Class 10 Geography and Environment

Chapter 4 Waste Management MCQs

Question 1. Carbon particles emitted by vehicles are controlled by the use of:
1. Cyclone Separators
2. Electrostatic Precipitator
3. Scrubber
4. Coated Alumina

Answer: 1. Cyclone Separators

Question 2. In the human body contaminated water may cause:
1. Diarrhoea
2. Asthma
3. Lung cancer
4. Blindness

Answer: 1. Diarrhoea

Question 3. The following waste material is non-biodegradable by its nature:
1. Plastic wastes
2. Synthetic rubber wastes
3. Aluminium sheet
4. All are applicable

Answer: 4. All are applicable

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Question 4. The process of waste management involves:
1. Reuse of waste
2. Recycling of waste
3. Reduction of waste
4. All of them

Answer: 4. All of them

Question 5. Cooked food is considered a:
1. Liquid waste
2. Gaseous waste
3. Solid waste
4. All of these

Answer: 3. Solid waste

Question 6. Vegetable peelings, bits of paper, etc. are
1. Non-toxic wastes
2. Toxic wastes
3. Liquid wastes
4. Gaseous wastes

Answer: 1. Non-toxic wastes

Question 7. The wastes that are generated from residential homes are called:
1. Industrial wastes
2. Domestic wastes
3. Agricultural wastes
4. Radioactive wastes

Answer: 2. Domestic wastes

Question 8. The wastes that are generated from hospitals are called:
1. Biomedical wastes
2. Industrial wastes
3. Domestic wastes
4. Radioactive wastes

Answer: 1. Biomedical wastes

Question 9. Hazardous and harmful wastes are called
1. Non-toxic wastes
2. Solid wastes
3. Toxic wastes
4. Liquid wastes

Answer: 3. Toxic wastes

Question 10. Burning of Uranium in nuclear reactors creates waste.
1. Radio-active
2. Toxic
3. Biomedical
4. Liquid

Answer: 1. Radio-active

Question 11. The method of using a liquid to remove waste is called
1. Composting
2. Scrubbing
3. Landfilling
4. Dumping

Answer: 2. Scrubbing

Question 12. The useless or worthless material stuff to be thrown away is called:
1. Resource
2. Waste
3. Neutral stuff
4. None of these

Answer: 2. Waste

 

Chapter 6 Satellite Imaginary And Topographical Map MCQs

Question 1. The colour used for drawing contour lines in the topographical map is:
1. Brown
2. Black
3. Red
4. Blue

Answer: 1. Brown

Question 2. The latitudinal and longitudinal extension of million sheet topographical map is:
1. 15′ x 15′
2. 30′ x 30′
3. l°xl°
4. 4°x4°

Answer: 4. 4°x4°

Question 3. The satellite sent by India is ______
1. IRS
2. LANDSAT
3. SPOT
4. Station

Answer: 3. SPOT

Question 4. The R.F. of a topographical map with 15’xl5′ latitudinal and longitudinal extension is ______
1. 1: 2,50,000
2. 1:1,00,000
3. 1:50,000
4. 1: 25,000

Answer: 4. 1: 50,000

Question 5. Satellites images are powerful tools of Meteorology as they:
1. Forecast the behaviour of the atmosphere
2. Identify the shipping route
3. Do landuse mapping
4. Identify physiography

Answer: 1. Forecast the behaviour of the atmosphere

Question 6. The satellite that remains in a fixed location on the earth’s surface is called:
1. Polar-orbiting satellite
2. Geostationary satellite
3. Data collecting system
4. None of these

Answer: 2. Geostationary satellite

Question 7. The satellite images that can be viewed during the day are:
1. Infrared imagery
2. Water vapour Imagery
3. Analogue satellite images
4. Visible imagery

Answer: 4. Visible imagery

Question 8. Topographical maps usually are:
1. Small-scale maps
2. Large-scale maps
3. Cadastral maps
4. Weather maps

Answer: 2. Large-scale maps

Question 9. In order to describe surface features, topographical maps use:
1. Scale
2. North line
3. Conventional signs
4. None of these

Answer: 3. Conventional signs

Question 10. The sensors in the satellites use to take images.
1. Conventional Camera
2. Digital Camera with CD
3. A mobile phone
4. None of these

Answer: 2. Digital Camera with CD

Question 11. The link between the earth and the sensor is:
1. Troposphere
2. Stratosphere
3. Electromagnetic wave
4. Short waves

Answer: 3. Electromagnetic wave

Question 12. Satellite imageries are photographs taken by______
1. Satellites
2. Planets
3. Manual cameras
4. Mobile phones

Answer: 1. Satellites

Question 13. Satellite imageries help to gather information regarding______
1. Only land bodies
2. Only water bodies
3. The earth as a whole
4. Mountains and Plateaus only

Answer: 3. The earth as a whole

Question 14. Satellites take photographs at _____ intervals.
1. Very small
2. Very long
3. Moderate
4. Not frequent

Answer: 1. Very small

Question 15. Topographical maps represent ______ features.
1. Physical
2. Cultural
3. Both physical and cultural
4. One of these

Answer: 3. Both physical and cultural

Question 16. Topographical maps are prepared by ______
1. Survey of India
2. Geological Survey of India
3. NAME
4. NATO

Answer: 1. Survey of India

Question 17. Weather forecasting is possible through_____
1. Satellite images
2. Topographical maps
3. Both
4. None

Answer: 1. Satellite images

Question 18. The images of earth and other planets collected by satellites are called:
1. Maps
2. Photographs
3. Satellite images
4. None of these

Answer: 3. Satellite images

 

India Location, Administrative Divisions True Or False Type:

Question 1. Sri Lanka is a neighboring country that shares a boundary with India.
Answer: False

Question 2. The largest union territory is Pondichery.
Answer: False

Question 3. Haryana attained statehood in 1966.
Answer: True

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 4. Goa, Daman, Diu became a part of India in 1961.
Answer: True

Question 5. State Reorganisation Committee was set up in 1953.
Answer: True

Question 6. Himachal Pradesh was made a full-fledged state in 1970.
Answer: True

Question 7. Chandigarh is the capital of Punjab and Haryana.
Answer: True

Question 8. The largest state of India is Madhya Pradesh.
Answer: False

Question 9. The extreme southern point of India is Indira point.
Answer: True

India Location, Administrative Divisions  Fill In The Blanks Type:

Question 1. The total area of India is ______ sq. km.
Answer: 32,87,263 sq. km.

Question 2. The newest state of India is ______.
Answer: Telangana.

Question 3. India includes 29 states & ______ Union Territories.
Answer: 7.

Question 4. Meghalaya became a state in ______.
Answer: 1972.

Question 5. Manipur attained statehood in ______.
Answer: 1972.

Geography Class 10 West Bengal Board

Question 6. Mysore became Karnataka in ______.
Answer: 1973.

Question 7. State Reorganisation Act was passed in ______.
Answer: 1953.

Question 8. Arunachal became a state of India in ______.
Answer: 1987.

Question 9. Haryana became a state of India in ______.
Answer: 1966.

Question 10. The largest state of India is ______.
Answer: Rajasthan.

Question 11. The smallest state of India is ______.
Answer: Goa.

India Location, Administrative Divisions Very Short Answer Type:

Question 1. In which year India became the Sovereign Democratic Republic?
Answer: On 26th January 1950, India became the Sovereign Democratic Republic.

Question 2. How many states are there in India at present?
Answer: There are 29 states at present in India.

Question 3. How many union territories are there in India at present?
Answer: There are seven union territories in India at present.

Question 4. When was Mysore’s name changed to Karnataka and that of Laccadives, Minicoy, and Amindivi to Lakshadweep?
Answer: Both in 1973.

Question 5. What was the position of India in 1956?
Answer: There were 14 states and 6 union territories in India in 1956.

Question 6. When was the State Reorganisation Committee was set up?
Answer: In 1953, State Reorganisation Committee was set up.

Geography Class 10 West Bengal Board

Question 7. How many Union Territories are there in the Indian Union?
Answer: Seven.

Question 8. What was the main basis of state reorganisation in India?
Answer: Language and Population.

Question 9. What is the area of India?
Answer: 32,87,263 sq. km.

Question 10. When did Meghalaya come into being as a state?
Answer: 1972 A.D.

Question 11. In which year Himachal Pradesh became a state?
Answer: 1971 A.D.

Question 12. In which year Andhra Pradesh became a state?
Answer: 1953 A.D.

Question 13. In which year Haryana became a state?
Answer: 1966 A.D.

Question 14. In which year Chhattisgarh came into being as the 26th state of India?
Answer: 1st November 2000 A.D.

Question 15. In which year Uttaranchal came into being as the 27th state of India?
Answer: 1st November 2000 A.D!

Question 16. In which year Chhattisgarh came into being as the 28th state of India?
Answer: On 15th November 2000 A.D.

Question 17. In which year Sikkim became a constituent state of India?
Answer: 26th April 1975 A.D.

Geography Class 10 West Bengal Board

Question 18. In which year Mizoram and Arunachal Pradesh became full-fledged states of India?
Answer: On 20th February 1987 A.D.

Question 19. Which is the smallest union territory of India?
Answer: Lakshadweep.

Question 20. Which is the most densely populated state in India?
Answer: West Bengal.

Question 21. Name the most densely populated union territory of India.
Answer: Delhi.

Question 22. In which year the State Reorganisation Act was passed?
Answer: in 1956.

Question 23. In which year Nagaland became a state?
Answer: In 1962.

Question 24. In which year Punjab was reorganized?
Answer: In 1966. It was made into two states: Punjab and Haryana.

Question 25. Which is the youngest state of India?
Answer: Telangana.

Question 26. Name a Cape in south India.
Answer: Cape Comorin.

India Location, Administrative Divisions 2 Marks Questions And Answers:

Question 1. When did Meghalaya come into being as a state? Who named it?
Answer: Meghalaya was carved out of Assam in 1970 as a Union Territory. It became a full-fledged State in 1972. It like many other places such of Marusthali, Arunachal Pradesh, etc. was named by Prof. S.P. Chatterjee, the doyen (the most respected person) of geography in India.

Question 2. Name the largest and the smallest States in India in terms of their area.
Answer: Rajasthan is the largest state in India and Sikkim is the smallest state in India.

Question 3. When were the following States formed:
(1)Andhra Pradesh, (2) Himachal Pradesh?
Answer:
(1) On 1st October 1953 out of Madras State.
(2) In 1954 Himachal Pradesh emerged as a centrally administered territory and in 1971 as a full-fledged State.

Geography Class 10 West Bengal Board

Question 4. When did Harayana and Chandigarh come into being?
Answer: On November 1st, 1966, Punjab was divided into Punjab and Haryana as full-fledged States and Chandigarh as a Union Territory.

Question 5. Where is New Delhi situated?
Answer: New Delhi, the capital of India, is within the Union Territory of Delhi-situated on the bank of the Yamuna River.

Question 6. When did (1) Dadra and Nagar Haveli and (2) Goa, Daman, and Diu become part of India?
Answer: (1) August 1961, (2) December 1961.

Question 7. In which year did (1) Nagaland, and (2) Arunachal Pradesh come into being?
Answer:
(1) Nagaland became a Union Territory in December 1957 and a full-fledged state in December 1963.
(2) In 1957, North-East Frontier Agency (NEFA) was carved out of Assam as a Union Territory. It was renamed Arunachal Pradesh in 1972.

Question 8. What was the position of India when she acquired independence in 1947?
Answer: At that time there were 15 states governed by governors, 5 states governed by chief commissioners and there were more than 600 princely states.

Question 9. What was the basis of the reorganization of the united states? In which year State Reorganisation Act was passed?
Answer: Language was the main basis of the state reorganization of India. The Act was passed in the year 1956.

Class 10 Geography WBBSE

Question 10. What was the main basis of state reorganisation in India and why?
Answer: Language was the main basis of state reorganisation in India because there was a widespread public demand for it.

Question 11. Name and locate the water bodies surrounding India.
Answer: India is surrounded by water bodies on three sides, i.e., the Bay of Bengal in the southeast, the Indian Ocean in the south, and the Arabian Sea in the southwest.

Question 12. Write the latitudinal & longitudinal extent of India.
Answer: India lies between 8°4′ (Cape Comorin) and 37°6′ (the northern extreme of Jammu & Kashmir) north latitudes, and 68°7′ (the western end of Gujarat) and 97°25′ (the eastern end of Arunachal Pradesh) east longitudes.

Question 13. Name two islands that covered India.
Answer: (1) Andaman & Nicobar Islands, (2) Lakshadweep.

India Location, Administrative Divisions 3 Marks Questions And Answers:

Question 1. State how West Bengal attained its present shape since the partition of India in 1947.
Answer: At the time of the partition of India, West Bengal was a truncated state northern and southern parts remained separated from each other. Cooch Behar became a part of West Bengal in 1948 and the French Chandanagar-Gourhati in 1954. In 1956 when the Purulia subdivision and parts of the Kishengunj subdivision of Bihar were added, the State attained its present shape.

Question 2. Name any three union territories of India along with their capitals.
Answer: Three union territories of India are :
(1)Lakshadweep: Kavaratti
(2)Damanand Diu: Daman.
(3)Andaman and Nicobar Islands: Port Blair.

Class 10 Geography WBBSE

Question 3. State three basis of division of states after Independence.
Answer: Basis of the division of states of India after Independence: After independence, the different states or provinces of India were demarcated on the basis of some criteria; namely, language, culture, administration skills, economic stability, and physical and geographical similarities.

1. Language: India is a land where people speak different languages in different parts of the country. Based on this, the states were demarcated in 1956, designating the region speaking a common language as one state. E.g. the region where most people speak Assamese was marked as Assam, and the region where most people speak Punjabi was marked as Punjab.
2. Administrative advantage arid skill: Although language was a criterion of demarcating states, only this could not work very well. E.g. Hindi is the main language spoken in Uttar Pradesh, Bihar, Jharkhand, Madhya Pradesh, and Uttaranchal. But if all these states were kept united as one single state, it would have covered a huge area, causing difficulty in administration. Also, Bengali is spoken in West Bengal and also dominantly in Tripura. But due to physical distance, these two states could not be put together.

3. Culture: Even though the language spoken is the same, the local cultures and rituals followed in a particular region may differ. Hence, for administrative efficiency, these regions are frequented in different states. For E.g. Bjhar has been fragmented into Bihar and Jharkhand.

Question 4. Explain the boundary of India.
Answer: Boundary: India is bordered by the snowclad Himalayas in the north, the India Ocean in the south, the Bay of Bengal, Bangladesh, and Myanmar (Burma) in the east, and the Arabian Sea and Pakistan in the west. The Himalayan Kingdom Nepal and Bhutan lie on the lap of the Himalayas in the north; China lies in the farther north. The three sides of the southern peninsula are washed by the Arabian Sea, the Bay of Bengal, and the Indian Ocean. India has a land frontier of 15,200 km and a coastline of 7,516 km. The Andaman and Nicobar Islands in the Bay of Bengal and Lakshadweep (island) in the Arabian Sea are part and parcel of the territory of India.

Class 10 Geography WBBSE

Question 5. To what extent India is located? Explain.
Answer: Extent: The mainland extends from the Himalayas in the north to the Cape Comorin (Kanyakumari, the southern-most tip of the mainland) in the south, measuring about 3,214 km from north to south and from the western end of Gujarat to the eastern end at Arunachal Pradesh, measuring about 2,933 km from west to east. India covers an area of 32,87,263 sq. km. In terms of area, India ranks seventh position among the countries of the world. Russia occupies the first position followed by Canada, China, the U.S.A., Brazil, and Australia.

Question 6. In 1950 how many states and union, territories were present in India? Explain.
Answer: In the political map of 1950, we see that there were 28 states in India, they were classified into four groups stated as follows:
(1)9, ‘A’ States governed by Governors,
(2)8, ‘B’
(3)10, ‘C’ States governed by Chief Commissioners, and
(4)1, ‘D’ Union Territory.

WBBSE Class 10 Geography Chapter 5 Question Answer India Location, Administrative Divisions 5 Marks Questions And Answers:

Question 1. Give an account of the location, extent, and boundary of India.
Answer:
Location: India is located in the southern part of Asia, the largest continent of the world. The country lies towards the north of the equator, i.e., in the northern hemisphere. The mainland lies between 8°4 ‘(Cape Comorin) and 37°6 ‘(the northern extreme of Jammu & Kashmir) north latitudes, and 68°7 ‘(the western end of Gujarat) and 97°25′(the eastern end of Arunachal Pradesh) east-longitudes. The Tropic of Cancer passes almost through the middle of the country. The southernmost tip of the Nicobar Islands, i.e., the Indira Point touches the parallel of 6°45 ‘north latitude. India] States governed by the Princes,

occupies a strategic position in Asia, looking across the seas to Arabia and Africa on the west and to Myanmar, Malaysia, and the Indonesian Archipelago on the east. Geographically, the Himalayan Range in the north keeps India apart from the rest of Asia. India occupies a central position in south Asia. Of her unique geographical position, Indian civilization and culture spread over the countries of southeast and southwest Asia. India’s geographical location also influences the climate of the country. The presence of the lofty Himalayas in the north checks the inward flow of the southwest Monsoon to make rain. This is of immense importance for Indian agriculture.

Class 10 Geography WBBSE

Extent: The mainland extends from the Himalayas in the north to the Cape Comorin (Kanyakumari, the southern-most tip of the mainland) in the south, measuring about 3,124 km from north to south and from the western end of Gujarat to the eastern end at Arunachal Pradesh, measuring about 2,933 km from west to east. India covers an area of 32,87,263 sq. km in terms of area. India ranks seventh position among the countries of the world. Russia occupies the first position followed by Canada, China, the U.S.A., Brazil, and Australia.

Boundary: India is bordered by the snowclad Himalayas in the north, the Indian Ocean in the south, the Bay of Bengal, Bangladesh, and Myanmar (Burma) in the east, and the Arabian Sea and Pakistan in the west. The Himalayan Kingdom Nepal and Bhutan lie on the lap of the Himalayas in the north. The three sides of the southern peninsula are washed by the Arabian Sea, the Bay of Bengal, and the Indian Ocean. India has a land frontier of 15,200 km and a coastline of 7,516 km. The Andaman and Nicobar Islands in the Bay of Bengal and Lakshadweep (island) in the Arabian Sea are part and parcel of the territory of India.

Class 10 Geography WBBSE

Question 2. Give an account of the existing provinces and Union Territories of India.
Answer:
Existing provinces and Union Territories of India: India at present is a federal union of states comprising 29 states and 7 union territories. The states and union territories are further subdivided into districts and further into smaller administrative divisions. Amongst the states of India, Rajasthan is the largest and Goa is the smallest state in terms of area. According to the size of population, Uttar Pradesh ranks the first and Sikkim the last position. The highest density of population prevails in West Bengal (1029 per sq km), while the lowest density of population is recorded in Arunachal Pradesh (17 per sq km). However, if we consider the population of the states and the union territories together, the highest density of population prevails at Delhi (11,279 per sq km) and the lowest at Arunachal Pradesh.
A table is given below to show the details of the states and union territories:

WBBSE Class 10 Geography Chapter 5 Question Answer

State	capital	Area in (sq. km)	Population (in thousands)	The density of Population(perqs. km.)
1. Andhra Pradesh	Hyderabad	160.205	49.386	308
2. Arunachal Pradesh	Itanagar	83743	1,382	17
3. Assam (Asom)	Dispur	78,438	31,169	397
4. Bihar	Patna	94,163	103.804	1,102
5. Chhatisgarh	Raipur	136,034	25,540	189
6. Goa	Panaji	3,702	1,457	394
7. Gujarat	Gandhinagar	195,024	60,383	308
8. Haryana	Chandigarh	44,212	25,353	573
9. Himachal Pradesh	Shimla	55,673	6,856	123
10 Jammu & Kashmir	Srinagar	2,22,236	12,548	124
11. Jharkhand	Ranch	79,714	32,965	414
12. Karnataka	Bengaluru	191,791	61,130	319
13. Keraia	Thiruvanthapuram	38,863	33,387	859
14. Madhya Pradesh	Bhopal	308,000	72,597	236
15 Maharashtra	Mumbai	307,713	112,372	365
16. Manipur	Imphal	22,327	2,721	122
17 Meghalaya	Shillong	22,429	2,964	132
18. Mizoram	Aizawl	21,081	1,091	52
19. Nagaland	Kohima	16,579	1,980	119
20. Odisha	Bhubaneshwar	155,707	41,947	269
21. Punjab	Chandigarh	50,362	27,704	550
22. Rajasthan	Jaipur	3,42,239	68,621	201
23. Sikkim	Gangtok	7,095	607	86
24. Tamil Nadu	Chennai	1,30,058	72,138	555
25. Telangana	Hyderabad	114,840	35,193	310
26. Tripura	Agartala	10,491	3,671	350
27. Uttarkhand	Dehradun	53,484	10,116	189
28. Uttar Pradesh	Lucknow	240,928	199,581	828
29 West Bengal	Kolkata	33.752	51 347	1,029
Union Territories
1. Andaman & Nicobar	3ort Blair	8,249	379	46
?. Chandigarh	Chandigarh	114	1.054	9,252
3. Dadrs 8 \agar Have	Silvassa	491	342	698
4. Daman & Diu	Daman	112	242	2,169
5. Delhi	Delhi	1,483	16.753	11,297
6. Lakshadweep	Kavaratti	32	64	2,0i3
7. Pondicherry	Pondicherry	479	1,244	2.593
India	New Delhi	3,287,263	1,21,01,93,422	382

Question 3. Write in brief about the history of the demarcation of provinces of India after independence.
Answer: India, a union of states, is a Sovereign Socialist Secular Democratic Republic. It became a Republic on 26th January 1950. In the political map of1950, we see that there were 28 states in India; they were classified into four groups stated as follows: 9, ‘A’ States governed by the Governors, 8, ‘B’ States governed by the Princes, 10, ‘C1 States governed by Chief commissioners and 1, ‘D’ Union Territory.

The State Reorganisation Commission was set up in 1953. According to the recommendation of the commission, the entire political setup of the country was reorganized on a linguistic basis. The classification of the States into ‘A’, ‘B1, and ‘C’ categories was abolished. Only two types of political divisions, namely ‘states’ and ‘union territory’ were recognised. The process of reorganization of states continued since 1st November 1956 and the political map of India went on changing. A short account of this is given below:

1. The years between 1957 and 1987 saw the divisions of the former Assam and the birth of full-fledged states, such as, Arunachal Pradesh, Nagaland, Meghalaya and Mizoram.
2. On 1st May 1960 Bombay was bifurcated into Maharashtra and Gujarat states.
3. In 1961 India occupied the Portuguese enclaves of Goa, Daman, and Diu.
4. On 1st December 1963 Nagaland became a full-fledged state of the Indian Union.
5. On 1st November 1966 former Punjab of the Indian Union has divided again and the present Haryana and Punjab came into being.
6. In 1971 Himachal Pradesh and in 1972 Manipur, Meghalaya and Tripura became full-fledged States.
7. On 26th April 1975 the Himalayan Kingdom Sikkim joined the Indian Union as its 22nd state.
8. On 20th February, 1987 Mizoram and Arunachal Pradesh, and on 30th May, 1987 Goa became the 2.3rd, the 24th and the 25th states of the Indian Union respectively.
9. On 1st November 2000 Chhattisgarh (Capital: Raipur), on 8th November 2000 Uttaranchal now known as Uttarakhand (Capital: Dehra Dun) and on 15th November 2000 Jharkhand (Capital: Ranchi) became the 26th, 27th and 28th States of India respectively.
10. On 2nd June 2014Telengana  carved out from the north-western region of Andhra Pradesh, appeared as the 29th State of India with the city of Hyderabad as its capital.

Geography Class 10 West Bengal Board Chapter 1 Exogenic Processes And Resultant Landforms True Or False Type:

Question 1. Cusec is the unit used for measuring river velocity.
Answer: False

Question 2. A floating ice mass in the sea is called an iceberg.
Answer: True

Question 3. The confluence of the Alakananda and Bhagirathi rivers is at Devprayag.
Answer: True

Question 4. The altitude of the snowline varies with latitude.
Answer: True

Question 5. Potholes are formed at the base of the waterfall.
Answer: False

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 6. Seif dunes are transformed from Barkhan dunes.
Answer: True

Question 7. Most of the deserts in the world lie on the western parts of the continents where trade winds blow offshore.
Answer: True

Question 8. One of the conditions of delta formation is that there should be large lakes in the river course.
Answer: False

Question 9. Outwash plains present glacial-fluvial landforms.
Answer: True

Question 10. Small streams and rivulets that join the mainstream are called distributaries.
Answer: False

Question 11. The uplands which divide the channels are known as water divides or watersheds.
Answer: True

Question 12. Drumlins are low elongated hills formed by glacial deposition.
Answer: True

Question 13. A series of cracks that develop on the surface of a glacier is known as Crevasses.
Answer: True

Question 14. Outwash plains are formed by glacial deposition.
Answer: True

Question 15. The mobile dunes of Rajasthan are called Dhrians.
Answer: True

Question 16. The Ganga-Brahmaputra delta is the largest delta in the world.
Answer: True

Question 17. The ‘New Moore island’ is suspected to have submerged again.
Answer: True

Geography Class 10 West Bengal Board

Question 18. Overgrazing does not cause desertification.
Answer: False

Question 19. Deltas occur in the upper course of a river.
Answer: False

Question 20. Plucking is an important action of wind erosion.
Answer: False

Question 21. The largest Indian glacier is Siachen on the Karakoram.
Answer: True

Question 22. The mobile sand dunes of Rajasthan are known as Dorians.
Answer: True

Question 23. Flood plains are found in Glacial Region.
Answer: True

Question 24. Levees are common in river valleys.
Answer: True

Question 25. Deltas are found at the mouth of the rivers.
Answer: True

Question 26. Drumlins are common in the lower course of Glacier.
Answer: True

Question 27. Barkhan is common in the Desert Region.
Answer: True

Question 28. Zemu isa glacierof the Eastern Himalaya.
Answer: True

Question 29. Moraines are common in Glacial Valley.
Answer: True

Question 30. Pyramidal peaks are common in the Desert Region.
Answer: False

Question 31. One of the salient features of a river in its upper course is pothole.
Answer: True

Question 32. The landforms either carved out or build up by running water are called alluvial landforms.
Answer: True

Question 33. Abrasion is the mechanical wear and tear of the erosional tables in themselves.
Answer: False

Question 34. Canyons and gorges represent very deep and narrow valleys.
Answer: True

Question 35. Rapids are of much wider dimension than waterfalls.
Answer: False

Question 36. The narrow flat surface on either side of the valley floor are called the river terrace.
Answer: True

Question 37. The side cutting of a river is mostly found in upper course.
Answer: True

Geography Class 10 West Bengal Board

Question 38. An ideal river has three courses.
Answer: True

Question 39. The highest waterfall in the world is the Niagra.
Answer: False

Question 40. Flood plains are found in glaciated regions.
Answer: False

Question 41. The course from the source to its mouth is the basin of the river.
Answer: True

Question 42. Hanging Valley is common in a glacial valley.
Answer: True

Question 43. Cirques are common in mountain areas.
Answer: True

Question 44. Snowline is the height above which the snow never melts.
Answer: True

Question 45. The snow line does not vary due to latitude and the nature of slope.
Answer: False

Question 46. A glacier is a large mass of moving ice.
Answer: True

Question 47. Levees are common in river valleys.
Answer: True

Question 48. The action of the wind is dominant in humid regions.
Answer: False

Question 49. A large depression formed by deflation is called a blowout.
Answer: True

Question 50. Steep sides overhanging ridges of hard rocks are called Yardangs.
Answer: True

Question 51. Zeugens are formed when soft rocks lie under a layer of hard rocks.
Answer: True

Question 52. Inselbergs are mostly found in the Sahara desert.
Answer: False

Question 53. Mushroom rocks are formed in desert areas.
Answer: True

Question 54. The rocks with hanging broad upper parts and narrow bases resembling an umbrella are called Mushrooms.
Answer: True

Geography Class 10 West Bengal Board

Question 55. The lakes formed in deserts are known as Playas.
Answer: True

Question 56. The rocky desert is called Ery.
Answer: False

Question 57. Barkhan is a longitudinal dune.
Answer: False

Question 58. The rivers move swiftly and create round holes by corrasion on the river bed called deflation hollows.
Answer: False

Question 59. The knife-like sharp serrated ridge between two corries is called an Arete.
Answer: True

WBBSE Class 10 Geography Solutions Chapter 1 Exogenic Processes And Resultant Landforms Fill In The Blanks Type:

Question 1. The Nile delta is ______ shaped.
Answer: arcuate

Question 2. The highland between two adjacent corries is called ______.
Answer: Arate

Question 3. The process of modifying landforms by the combined action of erosion and weathering is called _____.
Answer: Denotation.

Question 4. Holes formed by abrasion on river bed are called _______.
Answer: Pothole.

Geography Class 10 West Bengal Board

Question 5. After the name of ______ river, the zigzag course of a river is known as a meander.
Answer: Menderes.

Question 6. Horizontal and parallel cracks or fractures found on the surface of a glacier are called ______.
Answer: Crevasse.

Question 7. The plantation of landmass caused by different exogenic forces is called ______.
Answer: Graduation.

Question 8. Long, narrow, winding, steep-sided ridges formed by the fluvioglacial deposits of sands and gravels is called ______.
Answer: Esker.

Question 9. Sundarban is located on the delta of the three rivers _______,______ and ______.
Answer: Ganga, Brahmaputra and Meghna.

Question 10. ______ are low elongated hills formed by glacial deposition.
Answer: Drumlins.

Question 11. _______ or rock pedestal is produced by wind erosion.
Answer: Gour.

Question 12. The hard stony ribs of ridge and furrow topography formed due to wind erosion (on vertical bands of hard and soft rocks) are called ______.
Answer: Yardangs.

Question 13. The steep-sided deep valley produced by a river is called ______.
Answer: V-shaped valley.

Question 14. U-shaped valley is produced by the erosive action of ______.
Answer: Glacier.

Question 15. ______ are typical cresent-shaped sand dunes.
Answer: Barkhans.

Question 16. Flood plains are found in the _______ course of a river.
Answer: Lower.

Question 17. ______ is an agent of Gradation.
Answer: River.

Question 18. ‘U’-shaped valley is common is the ______ region.
Answer: Glacial.

Question 19. ‘V’-shaped valley is common in the ________.
Answer: River Basin.

Question 20. Deltas are the creation of a ________.
Answer: River.

Question 21. _______ are common in the limestone region.
Answer: Stalactites.

WBBSE Class 10 Geography Solutions

Question 22. Fossils are found in the _______.
Answer: Sedimentary Rock.

Question 23. The largest Glacier of India is _______.
Answer: Siachen.

Question 24. ________ is the largest Piedmont Glacier.
Answer: Malaspina.

Question 25. _______ is the main work of a river in the upper course.
Answer: Erosion.

Question 26. The naturally formed raised banks of a river are called _______.
Answer: Natural Levees.

Chapter 1 Exogenic Processes And Resultant Landforms Very Short Answer Type Questions:

Question 1. Which bank of a river meander experiences more erosion?
Answer: Concave slope / Outer bend

Question 2. At which altitude, the snow line is found in polar region?
Answer: sea level / 0 meter

Question 3. Name the sand dunes formed parallel to the wind direction.
Answer: Self-dunes / longitudinal dunes

Question 4. Name the largest valley glacier of the world.
Answer: Hubbard (122 km.)

WBBSE Class 10 Geography Solutions

Question 5. What is the name of the Sandy desert in the Sahara?
Answer: Ergs.

Question 6. From where the word ‘meander’ has been derived?
Answer: The word ‘meander’ is derived from the name of a small winding river ‘Meanders’ in Turkey.

Question 7. Which activity out of erosion and. deposition by river increases due to rejuvenation?
Answer: Erosion.

Question 8. In which stage does the incident river capture take place?
Answer: N.M. Davis.

Question 9. Give a single term for each of the following:
1. A stream that gets divided into a network of interconnected channels.
Answer: Braided Stream.

2. Raised banks of natural embankments built up of coarse deposits along the river channel.
Answer: Natural Levees.

3. Winding sections or loops of a stream.
Answer: River Meander and Oxbow lake.

4. A higher ground separating two adjoining drainage basins.
Answer: Water Divide.

5. A drainage pattern looking like the trunk and branches of a tree.
Answer: Dendritic pattern.

Question 10. Who put forward the idea of the ‘cycle of erosion’?
Answer: W.M. Davis.

Question 11. What are the three stages of the cycle of erosion?
Answer: Youth, maturity and old age.

WBBSE Class 10 Geography Solutions

Question 12. What is the deep vertical crack which opens up at the head of the glacier called?
Answer: Bergschrund.

Question 13. Name the typical crescent-shaped sand dunes in a desert.
Answer: Barkhans.

Question 14. What is the other word used to indicate the expansion of deserts?
Answer: Desertification.

Question 15. What is the shape of a glacial valley?
Answer: U-Shaped.

Question 16. What is Snout?
Answer: The glacier’s downstream end is known as the snout.

Question 17. What is Wadi?
Answer: The river valley created by the erosive action of rainwater due to sudden torrential showers in desert areas is called ‘Wadi1.

Question 18. What is Pediment?
Answer: The highly eroded plain formed at the foot of the mountain due to erosive actions of both wind and running water in deserts is called ‘Pediment’.

Question 19. Who coined the term ‘Inselberg’?
Answer: S. Passage, a German geomorphologist.

Question 20. Who coined the term ‘Roche Moutonnee’?
Answer: De Saussure in 1804.

Question 21. What is a wind gap?
Answer: The weak place between the elbow of capture and the upper portion of the cutted river is called the ‘wind gap’.

Question 22. What is the ‘sixth power law’?
Answer: ‘Gilbert’ propounded his famous ‘sixth power law’, which states that rate of the discharge of water is directly proportional to the velocity of the river.

Question 23. In which regions sand dunes are found?
Answer: In the Desert Region and in the Coastal Region sand dunes are found.

WBBSE Class 10 Geography Solutions

Question 24. Name the largest valley glacier of India.
Answer: Siachen.

Question 25. Name the largest Piedmont glacier in the world.
Answer: Malaspina in Alaska (U.S.A).

Question 26. Name the local names of the sand dunes of the Malabar coast (Kerala).
Answer: Teries.

Question 27. Name the local name of the lagoons in the Malabar coast.
Answer: Kayal.

Question 28. Name the glacier of the Eastern Himalayas.
Answer: Zemu glacier.

Question 29. Which is the largest desert of the world?
Answer: Sahara desert in North Africa.

Question 30. Name the desert of India.
Answer: The Thar desert.

Question 31. In which continents are the Atacama and Kalahari deserts located?
Answer: Atacama in South America and Kalahari in Africa.

Question 32. What is the name given to the sandy desert in the Sahara?
Answer: Erg.

Question 33. What name is given to the stony desert in Algeria?
Answer: Reg.

Question 34. What is Hammada?
Answer: Hammada is the name given to the rocky desert of the Sahara.

Question 35. What is the other name of mushroom rock?
Answer: Gaur or Gara or Pedestal rock.

Question 36. Name the area of the largest loess deserts.
Answer: North China.

Question 37. Name two important features formed by the depositional work of the wind.
Answer: Sand dunes and loess.

WBBSE Class 10 Geography Solutions

Question 38. Define a glacier.
Answer: A glacier is a mass of snow and ice that moves slowly over the land away from the place of accumulation.

Question 39. Who proved that glaciers are not static but they move forward?
Answer: Louis Agassiz.

Question 40. What is the significance of snowlines?
Answer: Snow never melts above the snowline. A huge mass of snow above the snowline gives birth to glaciers.

Question 41. Name the biggest continental ice sheet of the world.
Answer: Antarctica.

Question 42. What is Playa?
Answer: The small salt lakes present in desert regions are called playa.

Question 43. Name the largest canyon of the world.
Answer: Grand Canyon of river Colorado in the U.S.A.

Question 44. Which is the largest delta of the world?
Answer: The Ganga-Brahmaputra Delta in India.

Question 45. What will be the transport competence of a river if its velocity is doubled?
Answer: 64 times. [The transport competence is proportional to the sixth power of the velocity of the stream.]

Class 10 Geography Chapter 1 West Bengal Board Chapter 1 Exogenic Processes And Resultant Landforms 2 Marks Questions And Answers:

Question 1. Define “Graduation”.
Answer: Gradation is the process of levelling of the land by natural agents like rivers, groundwater, winds, glaciers, and sea waves. The processes in gradation are erosion, transportation, and deposition.

Question 2. What is an alluvial cone?
Answer: As the river comes suddenly from its upper course to its middle course, its velocity decreases and its sediments are deposited along with the flow of the river resembling the shape of a cone or fan. This is known as the Alluvial cone.

Question 3. What do you mean by “piedmont glacier”?
Answer: In temperate regions, the snow line descends quite low. Here small glaciers descend at the foot of the mountains and start meeting with each other. It is called the piedmont glacier.

Question 4. Define “transverse dune”
Answer: A large, strongly asymmetrical, elongated dune lying at right angles to the prevailing wind direction. Transverse dunes have a gently sloping windward side and a steeply sloping leeward side. They generally form in areas of sparse vegetation and abundant sand.

Question 5. What do you mean by”Maidan”?
Answer: A wide flat land area whose height is generally low. Generally, flat and wide areas up to 150 meters above sea level are called plains.

Class 10 Geography Chapter 1 West Bengal Board

Question 6. What is “Rann of Kutch”?
Answer: The Rann of Kutch is a salt marsh located in the Thar Desert in the Kutch District of Gujarat. Also referred to as the White Desert, it is about 30,000 sq. km. in size and is reputed to be one of the largest salt deserts in the world.

Question 7. What is Bergschrund?
Answer:
Bergschrund: A bergschrund is a long narrow crack developed at the source of the glacier. This is created when the mass of ice tends to flow down due to gravity and the mountain’s walls tend to hold back the ice due to friction.

Question 8. What is Canyon?
Answer:
Canyon: The valley formed by the river in its upper course in which vertical erosion is much greater than lateral erosion is known as an l-shaped valley as it resembles the English alphabet ‘I’. This valley is very narrow and very deep. It is also called Canyon.

Question 9. What do you mean by “Inselberg”?
Answer: Inselberg is a small, rounded hill, knob, ridge, or mini-mountain that rises abruptly from relatively flat surroundings. It is also called a monadnock.

Question 10. What is Plunge Pool?
Answer: In mountainous regions, waterfalls are created where the river drops from a considerable height with great velocity. Small depressions or hollows known as potholes are created at the base of the waterfalls due to the pounding of rock fragments brought down by the water. These potholes gradually grow bigger in size to form Plunge Pools.

Question 11. Define Loess.
Answer: Loess, an unstratified, geologically recent deposit of silty or loamy material that is usually buff or yellowish brown in colour and is chiefly deposited by the wind. Loess is a sedimentary deposit composed largely of silt-size grains that are loosely cemented by calcium carbonate.

Question 12. What is denudation?
Answer: Denudation involves the processes of weathering, erosion and transportation together. It is a term derived from the Latin word ‘denudate’ meaning ‘to strip bare’. It, therefore, causes the removal of rock layers from the earth’s surface resulting in the lowering of the land surface.

Question 13. How are the “deflation hollows” formed?
Answer: ‘Deflation hollows’ or deflation basins are formed by sweeping away of loose, light and dry sand particles by wind. They are also known as ‘desert hollows’ or ‘blow-outs’.

Class 10 Geography Chapter 1 West Bengal Board

Question 14. What is Iceberg?
Answer:
Iceberg: Huge blocks of ice that break off from glaciers and fall into the sea are called icebergs.

Question 15. How are the bird’s foot deltas formed?
Answer: The deltas that look like a bird’s claw or fingers spreading one beside the other, are called bird’s foot deltas. Eg. Delta of the river Mississippi in North America.

Question 16. What is an estuary? What geographical conditions are needed for its formation?
Answer: Some rivers have strong tidal currents at their mouths and so the materials brought down by these rivers to their mouths are carried far into the sea. Deposition of materials at the mouth is almost impossible. The mouths of such rivers are very wide. The wide mouths of tidal rivers are known as estuaries. The mouth of the Thames is a typical estuary.

Question 17. What are the different types of deltas?
Answer: Three types of deltas are usually distinguished:
1. Arcuate or fan-shaped, e.g. Nile.
2. Cuspate or pointed like a tooth, e.g. Ebro.
3. Birds-foot type with fingering branches, e.g. Mississippi.

Question 18. What part does water play to modify a desert landscape?
Answer: In a desert torrential short-lived rainstorms cause sheet floods on level ground and flash floods down slopes and channels. Such occasional floods are disastrous.

Water action produces:
1. Wadis: large dry channels,
2. Bajadas: piedmont alluvial plain produced by the merger of a number of alluvial fans, and
3. Playas, Salinas, Dhand’s, and Bolsons: all different names for salt lakes.

Class 10 Geography Chapter 1 West Bengal Board

Question 19. How do we identify a river’s realm or domain? What is a divide or watershed?
Answer: The land drained by a river, a natural drain, is the river basin; the area which supplies water is its catchment. Basin is a part of the catchment, and the two together constitute the domain of the realm of a river. A divide or watershed is the edge that divides two river basins.

Question 20. Distinguish between a bed and a valley.
Answer: A river flows in its bed which lies at the bottom of a curb called a valley. Although a river down cuts to form a valley floor, the shape of the valley sides is determined by mass wasting, which widens the narrow-cut bed made by the river.

Question 21. What is a basket of egg topography?
Answer: Basket of egg topography: When the Glacier faces an obstruction in its path, its load is more than it can carry, it dumps its load. These mounds taper two ends along the flow of the glacier, resembling upturned boats or eggs, as they are high at the centre, elongated and pointed at two ends. These are called Drumlins. Many drumlins deposited widely are also called “Basket of Eggs” topography.

Question 22. What is a glacier?
Answer: The term glacier is derived from the French word ‘Glace’, meaning ice. A huge mass of ice compressed and formed by the consolidation under the pressure of snow that moves slowly over land is called glacier.

Question 23. here is the source of the river Yamuna.
Answer: Yamuna originates from the Yamunotri glacier situated at the West of Gangotri (Uttranchal).

Question 24. What is a flood plain?
Answer: Floodplain All great rivers have wide-level lands adjacent to their banks over which they spill their waters in times of flood and deposit alluvium. Such low-lying alluvial plains built by rivers mainly during high water are called flood plains.
Example: Flood plains of the Ganga and Brahmaputra.

Question 25. What are the works of a river?
Answer: There are three works of a river
1. Erosion (in upper or mountain course),
2. Transportation (in the middle or plain course),
3. Deposition (in lower or delta course).

Class 10 Geography Chapter 1 West Bengal Board

Question 26. Where are alluvial cones formed?
Answer: Alluvial cones are formed at the foothills of mountains where the river suddenly changes its slope from steep to gentle. Its velocity also suddenly decreases. So, the river’s carrying capacity suddenly drops & it deposits pebbles & other coarse materials at the junction of the mountain & plain. The shape of the deposition is like fan or cone, so it is called an alluvial fan or cone. They are found abundantly in the Terai region of the Himalayas.

Question 27. Name three features produced by wind erosion.
Answer: Features produced by wind erosion are
1. Inselberg,
2. Ventifact,
3. Gour.

Question 28. What is Dhand? Where it is found?
Answer: Deflation is a process of wind erosion occurring in desert regions. The high speed of wind lifts sand from one region & carries it. Thus, by the lifting of sand many big & small depressions formed. The small depression produced by deflation is called Dhand. It is found in the Rajasthan desert of India.

Question 29. What is Kame?
Answer: At the end of a glacier when among the terminal moraines, snow meltwaters cause the various stones, rocks, pebbles & clay, etc. to form a mould-shaped deposition with three-sided angular, is called Kame.

Question 30. Why is the river Ganga called an ideal river?
Answer: River Ganga is called an ideal river because it clearly shows three courses,
1. Youthful or upper course,
2. Maturity or middle course and
3. Old or lower course.

Question 31. What is the discharge of a river?
Answer: The discharge of a river is the combination of the volume and velocity of the river. It is measured in cusec (a cubic foot of water passing through the river at a point per second).

Question 32. Name two rivers of India which form an estuary.
Answer: The Narmada &Tapti rivers of India form an estuary.

Class 10 Geography Chapter 1 West Bengal Board

Question 33. What are rapids & cascades?
Answer: When waterfalls have less steep slopes, they are called rapids. So, we may call them small waterfalls. It is found in the hilly regions of the Chhotanagpur plateau. When waterfalls flow down in many steps or in many channels or branches, they are called cascades.

Question 34. Give an example of a mountain glacier.
Answer: Zemu glacier (26 km in length) in the Karakoram mountain range is an example of a mountain glacier.

Question 35. What is Cirque?
Answer: Cirque is a basin (looks like a handle of a deck chair) cut into the side of a mountain by glacial erosion at the head of a glaciated valley.

Question 36. What is Hanging Valley?
Answer: The hanging valley is a valley of tributary glaciers located high above the valley of the main glacier. The streams in the hanging valley descend to the main valley as a waterfall.

Question 37. What is Roche moutonnee?
Answer: Roche moutonnee is a rock mound modified by glacial erosion. Its upstream surface is gently sloping & smooth while its downstream surface is steep & rough.

Question 38. Which is the largest glacier of the world?
Answer: Beardmore (160 km in length) which is the Antarctic continental glacier is considered the largest glacier in the world.

Question 39. Where is the world’s only equatorial glacier?
Answer: Mt. Cotopaxi in Equador supports the only glacier on the equator.

Question 40. What is a river?
‘Answer: According to Jackie Smith, “A river is a large stream of fresh water flowing down from the hills within a channel to enter or a lake or sea”.

Question 41. What is a river basin?
Answer: The principal river with its tributaries and distributaries drains a vast area. It looks like a basin. The area which is drained by a river and its tributaries and distributaries is called a river basin. The Ganga Basin is the largest river basin in India. The Amazon Basin of South America is the largest river basin of the world.

Question 42. What is water partings?
Answer: The highlands between the two adjacent river basins, which forms a natural boundary between the adjacent river basins, is called watershed or water partings.

Question 43. What are Interfluves?
Answer: The highlands separating one river valley from the next are called Interfluves.

Question 44. What are tributaries?
Answer: Tributaries are the smaller rivers that join the main river carrying the water from its surrounding.

Question 45. What are distributaries?
Answer: Distributaries are the branches or outlets which leave the main river carrying its water to the sea or lake.

Question 46. How far does the mountainous course of the river Ganga extend?
Answer: The mountainous course of the river Ganga extends from the icy cave of Gomukh on the Himalayas to the foothills at Haridwar.

Class 10 Geography Chapter 1 West Bengal Board

Question 47. In which part of the course of a river depositional activity is most prominent?
Answer: The depositional activity of a river is most prominent in the lower course.

Question 48. What is Dhrian?
Answer: The mobile sand dune of Rajasthan is known as Dhrian.

Question 49. What is the shape of the valley carved out by a glacier?
Answer: The shape of the valley carved out by a glacier is U-like, i.e., U-shaped.

Question 50. In which regions sand dunes are found?
Answer: Sand dunes are found in deserts (Arabian deserts, Rajasthan deserts) and coastal areas of seas and oceans.

Question 51. What is Espers?
Answer: The long ridge of material deposited parallel to the direction of flow of the meltwater is called espers.

Question 52. What are kettle lakes?
Answer: The melted water from glaciers may get accumulated in holes or depressions created in the outwash plains due to the melting of a detached mass of ice that might have been left partly or wholly buried. These are called kettle lakes.

Question 53. What is salt weathering?
Answer: Salt crystallisation causes the disintegration of rocks when saline solution seeps into cracks and joints in the rocks and evaporates, leaving salt crystals behind. These salt crystals expand as they are heated up, exerting pressure on the confining rock. This is known as salt weathering.

Question 54. What is Stone Lattice?
Answer: When a rock with parallel series of hard and soft strata of an area is arranged both in horizontal as well as in vertical directions, a Stone Lattice is formed.

Question 55. What is Demoiselle?
Answer: There are many areas which are made of hard rocks. Winds subject the upper parts of the rocks to abrasion but the lower parts remain protected. The protected soft rock stands like a pillar below the hard rock and is known as Demoiselle or Earth Pillars.

Question 56. What do you mean by Col or Pass?
Answer: Col or Pass: When two cirques from opposite sides of a hill develop and meet each other, a col or a pass is formed. Many passes in the Alps were formed by glacial action. Some of the world’s passes are used for transportation.

Class 10 Geography Chapter 1 West Bengal Board

Question 57. What is Fjord?
Answer:
Fjord: Fjord is a long narrow inlet with steep sides or cliffs, created by glacial erosion. It is generally formed when a glacier cuts a U-shaped valley by ice segregation and abrasion of bedrock. Most fjords are deeper than the adjacent seas. There are many fjords on the coast of Norway, Alaska, Iceland, etc.

Question 58. Differentiate between the valley shapes formed by the river and the glacier.
Answer: The valley shape formed by the river is V-shaped, while the valley developed by the glacier is of U-shape.

Question 59. Name two important deltas in India.
Answer:
1. The Ganga and the Brahmaputra have the most extensive delta,
2. The Delta of the Mahanadi.

Question 60. What is deflation hollow?
Answer: A deflation hollow is a vast depression on the sandy desert developed by the deflation action of wind erosion, i.e., by lifting and blowing away of sands from the ground.
Example: The Qattara Depression in Egypt.

Question 61. What is a pyramidal peak?
Answer: When several cirques are developed on all sides of a mountain, a horn-shaped pyramid is formed by the glacial action and is known as the pyramidal peak.
Example: Neelkanth peak on the Himalayas.

Geography Class 10 Solutions WBBSE Chapter 1 Exogenic Processes And Resultant Landforms Short Notes:

Question 1. Sand bars.
Answer: While carrying a lot of sand, deposits, the path of wind is obstructed by vegetation, large rock pieces, bushes, etc. The wind dumps a part of its load where it is obstructed to form a mound of sand which is called sand. bars.

Question 2. Zeugen.
Answer: When the wind blows steadily in one direction for a considerable time, due to differential abrasion, the wind wears away the underlying softer rock through the joints (caused by mechanical weathering). The harder rock layer stands uneroded like a ridge. This is known as Zeugen. They are of varying heights (from 1.5 m to 45 m).

Question 3. Waterfalls.
Answer: When a river falls suddenly from a certain height along a vertical slope, it is known as a waterfall. Waterfalls are formed in mountainous regions, when
1. Water falls over a softer rock horizontally, soft rocks are eroded away rapidly; and
2. A hard rock bed lies vertically across a river. Niagara Falls in North America is a famous waterfall of the world. In India, the Narmada Falls at Jabalpur on marble rock presents a beauty scene. Victoria Falls in Africa has a name and fame.

Geography Class 10 Solutions WBBSE

Question 4. Alluvial fan.
Answer:
Alluvial cone or fan: As the river suddenly changes its slope from steep to gentle, its velocity decreases. Thus, the river’s carrying capacity also decreases and the loads are deposited at the juncture of the mountain with the plain. The sand, pebbles, etc. that are deposited, increase in width along the flow of the river, giving it a cone of fan-shape of alluvial deposit. This is called the alluvial cone or fan. At Haridwar along the river, Gange’s alluvial fans can be seen.

Question 5. Gour or Rock pedestal.
Answer: The rocks having broad upper parts and narrow bases resembling an umbrella or mushroom are called mushroom rocks or pedestal rocks. These are formed due to the abrasive works of wind. The base of the individual rock block is abraded vigorously from all sides because of variable wind directions. Active abrasion is limited to six feet height from the ground while the upper part is least affected by abrasion. These are also called “Gara” in Sahara.

Question 6. Delta.
Answer: Largest deposits of materials take place at the mouth of a river. The deposits are so vast that the flow of the river is obstructed and the river course turns in many branches and between each couple of branches, a fan-shaped alluvial land is formed. This land resembles the Greek alphabet (A)delta, thus, is known as delta. Some deltas are “arcuate” or “bow-shaped” and some are.”bird-foot”. The delta of the Nile is the bird-foot delta. The delta of the Ganga in southern West Bengal is the largest delta of the world.

Geography Class 10 Solutions WBBSE

Question 7. Barkhan.
Answer: When the sand-carrying wind blows constantly in a particular direction, the slightest obstruction, like a tuft of grass may cause typical crescent-shaped dunes in sandy deserts. They are known as ‘Barkhans’ or ‘Barchans’. Their windward slope is convex and gentle while their leeward slope is concave and steep. The rate of their movement is nearly one metre per day. They move in the direction of the prevailing wind. They are mostly found in the deserts of Atacama, Sahara, Kalahari and Arabia. These shifting dunes in the Indian desert are called Dhrians.

 

Question 8. Roche Moutonnee.
Answer: These are hillocks of rock of a glaciated mountain which have been smoothed by the glacier on the upstream side, and left rough and rugged, with steeper slopes on the downstream side. They resemble sheep lying on the hillside and are also called sheep rocks.

Question 9. Natural Levee.
Answer: Along the banks of an old river large deposits of materials take place every year when the river is in flood. This accumulation of materials becomes so much that the bank gets higher and higher after a long period of time. This raised bank is known as a natural levee. Sometimes the flood water is obstructed to flow out by the levees. Natural levees are found in the lower course of the Ganga and the Hwang-Ho rivers.

Geography Class 10 Solutions WBBSE

Question 10. Potholes.
Answer: Whenever a soft rock comes in the way of the river, it is eroded and scattered all around. Eddies are formed and water whirls around and produces depression by plucking the sediment up. This makes the depression deep and cylindrical. Sometimes these depressions look like discs and are known as potholes. Stone pieces also enter the potholes along with water and act as grinders. The potholes have a diameter varying from a few centimetres to many metres.

The depth of a pothole is greater than its diameter. Potholes of over 7 metres in depth have been observed. When the potholes grow in size they are called plunge pools. It is very difficult to escape once one is caught in a plunge pool. Some people call these potholes and plunge pools as Devil’s Punch Bowl or Witches’ Cauldron because they think that such formations are due to the work of some supernatural power.

Question 11. Glacial Trough.
Answer: It is formed due to glacial erosion when a long elongated valley is formed as a result of abrasion and depletion of snow in the armchair-like depression of cirque. A glacial trough can also be formed when the wall between two back-to-back cirques breaks, thus forming a long valley.

Question 12. Pediment.
Answer: In the hot desert area the frontal part of a mountain is broken by the action of wind and the rocks thus left have a moderate slope. No deposition of materials takes place. This is known as a pediment.

Geography Class 10 Solutions WBBSE

Question 13. Corrie and Arete.
Answer: Corrie and Arete are the different types of features produced by glacial erosion. In the source regions of glaciers, in high mountain regions, glacial erosion causes a light depression to be eroded in such a way that the mountainside is steepened to form a headwall and at its foot, a pronounced depression is created by erosion. When the glacier melts away in summer, these resemble an armchair-like depression called Corrie in English and Cirque in French.

Whereas, Aretes are formed when glacial erosion may cause adjacent corries to develop in the mountainside. The ridge that forms the boundary between the adjacent depressions is called the Arete.

Question 14. Yardang.
Answer: Yardangs are one of the various landform features developed out of aeolian erosion in desert regions. When hard and soft rocks are arranged vertically to the earth’s surface, then the soft rocks get quickly eroded forming long valleys while the hard rocks stand out as ridges called Yardang. These are generally 15 metres high and are found in the deserts of Central Asia. Sometimes hard and soft rocks stand parallel to the prevailing winds. Due to abrasion soft rocks are worn away and the hard ones stand as stony ribs. The whole area resembles ‘furrow’ or ‘ridges’. This phenomenon is known as ‘Yardang’. This is common in the Atacama desert.

Geography Class 10 Solutions WBBSE

Question 15. Interlocking spur.
Answer: Interlocking spurs are found in the upper course of a river, in mountain regions hard rocks or rocky ridges obstruct the flow of a river in such a way that the river has to keep on bending to overcome the hard rock obstructions. From afar, these obstructions look like spurs that are interlocking, so they are called interlocking spurs.

Question 16. Hanging valley.
Answer: As the main river has a tributary river, in the same way the main glacier has a tributary glacier. The valley of the main glacier is deeper than that of the tributary glacier. After the melting of snow, the tributary valley seems to be hanging over the main valley. This is called Hanging valley.

Question 17. Drumlin.
Answer: In a few areas, due to the depositional work of a glacier, hills of considerable height are found. They are mainly composed of boulder clay and are elongated in the direction of the moving glacier. They look like elongated ‘whale back’ hummocks and are shaped like a half eggs. They are called drumlins. Drumlins are found in Central Ireland, Tweed basin and North-Eastern U.S.A. Drumlins are formed singly or in groups. When they are formed in groups, a “basket of eggs” like landscape is developed, called “Egg Basket Topography”.

Geography Class 10 Solutions WBBSE

Question 18. Lagoon.
Answer: On the sea coast due to the action of sea waves and wind, accumulation of sand takes place. The shallow and small stretch of water which is separated from the sea by sand bars is known as a Lagoon. Chilka lake on the coast of Orissa is a good example.

Question 19. Abrasion.
Answer: It is one of the three ways by which wind erosion is caused. The wind drives sand dust particles against an exposed rock, thereby scratching, polishing and wearing away the face of the rock. This process is known as ‘abrasion’. It is most effective on the base of the rock when the wind carries big-sized materials in larger quantities.

Question 20.Loess plain.
Answer: Fine particles of clay are blown by the wind and are deposited in faraway areas. This is blown due to the action of very swift wind. That is why they are deposited without any layer or strata. The colour of these materials is yellow or light grey. This soil is very fertile. The plain of the Hwang-Ho is made of such soil.

WBBSE Class 10 Geography Solutions

Question 21. Moraine.
Answer: Moraines are fragments, particularly boulders and coarse materials like sand, clay, and gravel that are brought down with the movement of a glacier. These are of the following types:

1. Terminal or Marginal Moraine: When the materials brought down by a glacier are dropped at the end of the glacier, a Terminal or End Moraine is formed. Here at this point, the ice is melting.
2. Lateral Moraine: When the materials are deposited along the sides of the moraine, it is known as Lateral Moraine.
3. Medial Moraine: When two glaciers meet, the meeting lateral moraine of each glacier forms an inner moraine below the meeting point. The line of materials is called Medial Moraine.
4. Ground Moraine: The materials deposited beneath the glaciers are called Ground Moraine. It consists of rock materials of all sizes from clay to large boulders and is found scattered.
5. Recessional Moraine: When the accumulation of materials takes place in a terminal or end moraine, and the scattered materials are left behind the terminal moraine the successive moraines produced by successive drifts in ice retreat are called Recessional Moraine.

Question 22. Outwash plains.
Answer: These are smooth sloping plains lying in front of the glacial margin. They are made of fluvioglacial deposits. Such plains are formed by the material washed out by streams and channels of melting water. An outwash plain is best developed just outside the terminal moraines.

Chapter 1 Exogenic Processes And Resultant Landforms 3 Marks Questions And Answers:

Question 1. Discuss in brief about three processes of river transportation activity.
Answer:
Transportation: The work by which the river carries away the eroded materials from one place to another is called transportation, the materials that the river transports are called its load.

Class 10 Geography Chapter 1 WBBSE

There are four methods by which the river transports its load:
1. Solution: The materials like salts are usually dissolved in river water and are carried in solution.
2. Suspension: Sand, silt and mud are carried in suspension as the river flows. The majority of the river’s load (about 70%) is carried in this way.
3. Saltation: By this method, the larger loads jump up and then hit the bed and side of the channel and repeat this process to proceed further.
4. Traction load: The materials like rocks, boulders, pebbles, stones etc., which are too heavy to float are rolled along the river bed as traction (pulled) load.
The work of transportation is prominent in the upper and middle course of the river.

Question 2. State three differences between “Seif dune” and “Barkhan”.
Answer:

Barkhans	Seif dunes
1. The term Barkhan comes from the Turkish word ‘Barkhan’, meaning sand mountain.	1. The term Seif comes from the Arabian word ‘Seif’, meaning a straight sword.
2. Formed like a curve diagonal or perpendicular to wind direction.	2. Formed like straight lines parallel to the wind direction.
3. They are crescent-shaped dunes. The windward side is convex and the leeward side is concave.	3. They are narrow and straight and look like parallel ridges.

Question 3. Explain why a delta is formed at the mouth of a river.
Answer:
Formation of Delta: The velocity of the river is almost nil where it meets with the sea. Thus, the heaviest amount of depositions occurs here. The main channel is broken into numerous distributaries as more and more depositions take place. The region acquires a triangular shape and looks like the Greek letter Delta, hence the name.

Deltas develop under the following conditions:
1. The sea bed near the mouth of the river is very shallow.
2. Slope is negligible.
3. Tidal action is low.
4. Huge amount of bed load.

Class 10 Geography Chapter 1 WBBSE

Question 4. Why is wind action dominant in desert regions?
Answer: Although the wind blows over the whole of the earth, its action is predominant in arid regions. This is because:
1. No obstacle in wind direction: In desert regions, due to lack of rainfall, there is no or very less vegetation cover. Thus wind blows unhindered at high speed.
2. Loose and exposed soil: Lack of vegetation makes the soil loose and exposed to wind action.
3. High diurnal range of temperature: Great difference between day and night temperature causes rocks to crack and break due to contraction and expansion. This makes the work of the wind easier.

Question 5. Discuss three factors affecting the transportation work of a river.
Answer:
Factors affecting the transportation work of a river: Following factors influence the transportation work of a river:

1. Velocity of Water: The velocity of water flowing in a river is the most important factor which influences the capacity of the river to transport its load. The increase in the velocity of water tremendously increases the transportation power of the river water. The transport competence is proportional to the sixth power of the velocity of the stream. If the velocity of the stream water is doubled, its competence is increased by:
(2)⁶ = 2x2x2x2x2x2 = 64times.

2. Volume of Water: Other things being equal, the transporting power of the water becomes double if the volume of water is doubled.
3. Size of the River Load: A stream can carry a much larger load of fine material than that of the coarser type. The distance up to which the eroded material is carried depends upon the size and weight of the fragments.

Question 2. Discuss the factors affecting the erosional work of a river.
Answer: Following factors influence the erosional work of a river:
1. Velocity of Water: The erosional work of the river depends upon the velocity of water in the river. On the hill slopes, the velocity of running water is much higher as compared to flat areas. Therefore, the erosional work by the river is more in the mountainous areas as compared to the plain areas.

2. Volume of Water: The increase in the volume of water in a river increases its capacity to erode. Accordingly, a river in flood has greater erosional power. In dry season when the volume of water in the river decreases, its capacity to erode is reduced.
3. Nature of Rocks: Soft rocks such as limestone and sandstone are eroded easily by the river whereas the river takes long to erode hard rocks like granite.

4. Load of the River: The running water by itself has little erosive action. The double work of corrosion or degradation of rocks by mechanical means, and corrosion or chemical weathering of the solid rock supply the load or the cutting tools for erosion. The corrosive work is mainly dependent upon the sediment load which a river current drags along with it. The eroded rock material helps the running water in deepening or vertical downcutting into the bed of the channel, lengthening as well as widening a river valley.

The sand, silt and pebbles are carried within the stream water in solution or suspension. The stones from the rocks and boulders are rolled along the bed of the stream. The particles get smoothened and rounded as they strike against each other and against the sides and bottom of the river valley.

Class 10 Geography Chapter 1 WBBSE

Question 6. What are the agents of gradation? Which of them is the most important? Why?
Answer:
Agents of Gradation: Any natural agency which is capable of eroding and transporting earth material is known as an agent of gradation. The principal agents of gradation are water, snow, ice, wind and sea waves.

Rivers are the most important agents of erosion, transportation and deposition. That is, they carve their own valleys and carry the eroded material downstream where it is either deposited by the riverside or delivered into a lake or the ocean. Rivers are the most important agents in transporting the products of erosion.

They drain vastly larger areas than do glaciers, and, even in their short flowage on deserts, they are able to carry more material than the ever-present wind can. Weathering, mass wasting and rivers work together to shape the landscape.

Question 7. Explain how deltas are formed.
Answer:
Formation of Deltas: The main work of the river in its lower course is deposition. The materials brought down by the river are steadily deposited at its mouth and, as a result, new land is formed. The river cannot cut through it as the current at the mouth is very weak. So it divides into several branches and flows around the newly formed island. As the islands grow larger, they assume the shape of the Greek letter a, so it is called a delta. Most of the important rivers such as the Ganga, the Nile, the Mississippi, etc. have extensive deltas at their mouths.

Question 8. Explain the following:
1. Nunataks,
2. Ice shelves,
3. Iceberg.

Answer:
1. Nunataks: From the central dome of the ice cap, ice creeps out in all directions (extrusion process). The peaks of the loftier mountains project above the ice surface as nunataks (Eskimo word).
2. Ice-Shelves: When the ice sheets reach right down to the sea, they often float as shelves or tidal glaciers. They terminate in precipitous cliffs (seaward face).of ice called ice-fronts.

Class 10 Geography Chapter 1 WBBSE

3. Iceberg: The tongues of the tidal glaciers are torn off by the buoyance of the seawater and great chunks float away in the form of icebergs. In the northern hemisphere, icebergs are like castles, towering high above the water; 10,000-15,000 are formed each year mostly from Greenland carried south by East Greenland and Labrador Currents.

They are rarely found in the Pacific Ocean, as the Bering Strait is shallow and narrow. The southern hemisphere icebergs are mainly tabular, large floating islands of ice. They move at about 6 km per day. Icebergs melt when approaching warmer waters, dropping the rock debris that was frozen inside them on the sea bed.

Question 9. What is an exotic stream? Name and locate four.
Answer: Some delta plains are on desert coasts. They are built by large streams which are fed by the abundant precipitation of mountain regions. Such streams have sufficient volume to flow right across the deserts and to discharge their loads into the bordering sea. These are exotic streams. Outstanding among them are the Nile, the Tigris-Euphrates, the Indus and Colorado.

Question 10. Define alluvium. Name the four principal classes of the alluvial plain.
Answer: Alluvium is the weathered and eroded material that is carried and deposited by streams.
The principal classes of alluvial plains are
1. Delta plains,
2. Flood plains,
3. Piedmont alluvial plains, and
4. Plains of older alluvium.

Question 11. Define the terms source, mouth, tributaries and distributaries.
Answer: The place from where a river begins its flow, is called the source of the river, and the place where its flow ends, is called the mouth.

Small streams and rivulets that descend to join the mainstream are called tributaries. A mighty stream receives innumerable tributaries.
On the lower course of the river, particularly near the mouth, several branches come out from the main channel and these are known as distributaries of the river.

Class 10 Geography Chapter 1 WBBSE
Example: The Bhagirathi-Hooghly.

Question 12. What is a river basin?
Answer: The principal river with its tributaries and distributaries drains a vast area. It looks like a basin. The area which is drained by a river and its tributaries and distributaries is called a river basin. The Ganga Basin is the largest river basin in India. The Amazon Basin of South America is the largest river basin in the world.

Question 13. What do you mean by water partings or watersheds?
Answer: Sometimes, ridges and uplands separate the channels of running water. The uplands which divide the channels are known as water divides or watersheds or water partings. The Vindhya Range in central India divides the river basin of Narmada and Son. Elance, the Vindhyan range is a watershed between Narmada and Son rivers.

Question 14. Name and state the nature of work which a river does. Or, What are the works of a river?
Answer: As it begins to flow along the slope of the land, a river does a lot of work for its smooth journey to the sea. It reshapes the land through which it passes. The work of a river can be divided into three types:

(1) Erosion,
(2) Transportation and
(3) Deposition.

1. Erosion: It is the work of a river by which it wears away the land and breaks down its bed and the sides of its channel. The erosive actions of a river are of three types. These are:
(1)Solution,
(2) Attrition and
(3) Corrasion.

(1)Solution: this is the action in which the river dissolves the soluble rocks like limestone.
(2)Attrition: This is the action in which a load of a river such as pebbles and stones collide with each other and break into smaller pieces.
(3) Corrosion: The action in which river beds and sides of its channel wear away.

Corrasion is of two types:
(1) Vertical corrasion and
(2) Lateral corrasion.

(1)Vertical Corrasion: this is the process of down-cutting; when a river erodes downwards and deepens the valley, it is known as vertical corrasion.
(2)Lateral Corrasion: this is the process of side-cutting; when a river erodes the sides and widens the valley, it is known as lateral corrasion.

2. Transportation: The work in which the river carries away the eroded materials from one place to another is called transportation.
3. Deposition: The work in which the river deposits the transported material is called deposition.

Class 10 Geography Chapter 1 WBBSE

Question 15. How are glaciers formed?
Answer:
Formation of Glaciers: Low temperature and sufficient snowfall are the two important factors for the formation of a glacier. Snowfall that occurs on the high mountains and plateaus and in polar regions each winter, does not melt away completely even during the next summer. Year after year, it accumulates and vast snowfields are formed.

It gradually turns into ice; the first stage from snowflakes to ice crystals is called ’Neve1 or ‘firn1. These are gradually transformed into a solid mass of ice. Then under the force of its own weight, due to melting at the bottom under the influence of latent heat of the masses of ice and owing to gravitational force, the solid mass of ice starts moving and is called a glacier.

Question 16. What are the processes of aeolian erosion? Or, How does wind work in an arid region? Or, Name the processes involved in wind erosion.
Answer: Winds cause erosion in three ways they are
1. Deflation,
2. Abrasion and
3. Attrition.

1. Deflation: The process by which the wind lifts and rolls along the loose particles on the ground is known as Deflation. It, thus, lowers the desert surfaces and causes extensive depressions.
2. Abrasion: This is the process in which the wind drives sand dust particles against an exposed rock or solid surface and results in rock surfaces being scratched, polished or worn away. This process is known as abrasions. It works most effectively near the base of rocks, where material blown by the wind is of the biggest size and the largest quantity.
3. Attrition: In this process, wind-borne particles roll against one another in a collision they wear each other away for this, their sizes are greatly reduced and .grains take rounded form.

Class 10 Geography Chapter 1 WBBSE

Question 17. What are the three types of glaciers?
Answer: Glaciers are of three types:
1. Continental Glacier,
2. Valley Glacier or mountain glacier and
3. Piedmont Glacier.

1. Continental Glacier: Masses of ice which cover large areas of a continent are called Continental Glaciers. These are also called Ice-sheet.
Example: At present two major ice sheets are found in (1) Greenland and (2) Antarctica.

2. Valley or Mountain Glacier: The glaciers which originate and occupy mountain valleys are known as Valley Glaciers or Mountain Glaciers.
Example: The Gangotri Glacier of the Himalayas.

3. Piedmont Glacier: The word Piedmont means ‘the foot of the mountain’. The piedmont glaciers are formed by the union of the spreading ends of several mountain glaciers at the foot of the mountain.
Example: The Malaspina Glacier of southeast Alaska.

Question 18. What is sand dune?
Answer:
Sand Dune: A sand dune is a heap of sand. It is of several metres high. It moves with the prevailing winds. Sand dunes are formed by the accumulation of sand and are shaped by the movement of the wind. A sand dune is built up when the wind faces some obstruction in its paths, such as a bush, a tuff of grass or a large rock. Sand dunes are usually stationary, but they often move in the direction of the wind. However, they move very slowly. The mobile sand dunes of Rajasthan are known as Dorians.

Question 19. Into which parts can the course of a river be divided according to its work?
Answer: The course of an ideal river, from its source to its mouth, can be divided into the following three segments (sections) according to its mode of work:

1. The upper course, or the mountain course: In this stage, the main work of a river is erosion; however, it also does the work of transportation.
2. The middle course or the course on the plains: In this course, the main work of a river is transportation however, it also does the work of deposition.
3. The lower course or the course on the delta: Near the delta, a river does the work of deposition.

Question 20. Describe the factors on which the erosive power of a river depends.
Answer: The erosive power of a river depends upon the following factors:

1. Volume of water: It plays a vital role. A river cannot work more if the volume of water in the channel remains low. The ability increases with the rise of the volume of water. The volume of water that flows in a river is measured in a unit known as cusec or cubic metre per second.

2. Slope of the land: The ability to work of a river largely depends on it. As the slope increases, the velocity of flow increases too.
3. Load of a river: A load of a river acts as its tool. A river with a load of pebbles and stones can erode more.
4. Nature of land: The hardness of land exerts some influence on the work of a river. Soft rocks wear away easily, while hard rocks check the rate of erosion.

Question 21. What are the erosional processes of a river?
Answer: Erosion by a river is called fluvial erosion. River erosion is accomplished in the following ways, such as
1. Hydraulic plucking: Removing and carrying the loose bedrock by the action of the force of running water is known as hydraulic plucking.

2. Abrasion or Corrasion: The wearing away of rock beds by the collision of the flowing rock fragments and the static rocks is known as abrasion or Corrosion. It is of two types:
(1) Lateral Corrasion
(2) Vertical Corrasion.

3. Attrition: The process of the formation of finer materials by the pebbles, and stones being carried by a river due to collision with each other is known as Attrition.
Corrosion: The chemical weathering of the rocks is known as corrasion or solution. Rocks like limestone dissolve in the water.

Question 22. Describe the processes of river transportation.
Answer: A river transports the materials that had eroded as well as a greater mass of materials brought into the river flow. A river transports its load in several ways

1. Solution: When the soluble rocks are dissolved in water they are carried in the form of the solution by the river.
2. Suspension: The fine particles of the rocks remain in a suspended position as long as the force of the upward turbulence is stronger than the downward settling tendency of the particles.

3. Saltation(Latin: Saltere means to leap): The mode of transportation of eroded particles such as small pebbles which make intermittent leaps from the river bed is called Saltation.
4. Traction: Traction is the rolling of very big rocks along the floor of the river as they are too heavy to float in the river. So they roll along the floor of the river.

Question 23. What are the processes of glacial erosion?
Answer: Glacial Erosion consists of the following processes
1. Plucking: The pressure of the moving glacier on rocks along the mountainside pulls them and takes them away. This is called plucking.
2. Abrasion: Ice and its load move along and erode the rocks by scraping. It acts as a giant file grinding the floor and the sides.
3. Ploughing: Loose material is pushed ahead of the glacier, or rock material may fall from valley walls and come to rest on top of the ice.

Question 24. What is a snowline? Explain why its height varies.
Answer: Snowline is the lowest limit of perpetual snow:
The height of the snowline varies with latitude, altitude, seasons and precipitation.

Latitude: It is situated at sea level in the polar regions and about 5,000 metres in the equatorial regions.
Altitude: In the Alps and the Himalayas it moves between 3,000 and 5,000 m and higher still at Mt. Kilimanjaro on the equator.
Season and precipitation: On the southern slopes of the Himalayas the height of the snowline increases from east to Weston account of a progressive decrease in moisture supply. It varies from 4,000 m in the eastern part to 5,500 m in the western part. In summer it goes up, in the wet and cold season it comes down.

Class 10 Geography WBBSE

Question 25. Distinguish between a V-shaped valley and U shaped valley.
Answer:

V Shaped Valley	U Shaped Valley
1. This valley is formed by the downcutting of the river.	1. This valley is formed by the side cutting of glaciers.
2. Deep narrow valleys and T-shaped, known as Canyons.	2. A valley formed at a higher level is known as a hanging valley.
3. This valley is formed by the cutting and down cutting of the river bed.	3. It is formed when a glacier enters a ‘V-shaped valley.
4. Its shape resembles the letter V.	4. Its shape resembles the letter ‘U’.

Question 26. What is a floodplain? What is the difference between a river bank and a river bluff?
Answer: When there is little water in a river a lean flow silts and creates a wide and dry bed but sometimes there is so much water that a river attains a bankful stage and often surplus water spills as a flood. The valley floor over which a flood deposits silt is the floodplain. The river bed is walled by banks, the floodplains by bluffs.

Question 27. Differentiate between alluvial cone and delta.
Answer:

Alluvial cone	Delta
1. It is formed at a place where a river passes from arrow canyons to an open plain.	1. It is formed at a place where the river passes from the plain to the sea.
2. River doesn’t divide into distributaries.	2. River divides into distributaries.
3. It has no connection with the salt content of the river.	3. More the salt content, the more will be the chance of its formation.
4. It is formed in the middle stage of a river.	4. It is formed in the lower stage or mouth of a river.
5. It is always cone-shaped.	5. It is mainly triangular in shape.

Question 28. Differentiate between Yardangs and Barkhans.
Answer:

Yardangs	Barkhans
1. They are formed due to wind erosion.	1. They are formed due to wind deposition.
2. They are fixed in one position.	2. They migrate from one place to another.
3. They are roughly parallel to the wind direction.	3. They are transverse or at right angles to the wind direction.
4. They are formed of hard and soft rocks.	4. They are formed of sand particles.
5. They have flat tops.	5. They do not have flattops.

Question 29. Differentiate between Zeugen and Yardangs.
Answer:

Zeugen	Yardangs
(1)They arc horizontal layers of harder and softer rocks.	(1)They are vertical bands of harder and softer rocks.
(2)They are higher in height in comparison to yardangs.	(2)They are of comparatively low height.
(3)It is formed due to wind abrasion.	(3)It is formed due to wind abrasion and deflation.
(4)It forms caves and pillar-like structures.	(4)It forms ridges and valleys-like structures.

Question 30. Differentiate the river valley from the glaciated valley.
Answer:

Basis	River Valley	Glaciated Valley
1. Shape	V-shaped or l-shaped.	U-shaped.
2. Creating an agent	Flowing water of the river.	Sliding ice of the glacier.
3. Process of erosion	Corrasion as well as corrosion.	Abrasion and plucking.
4. Time of predominance	Predominates in the present day.	Predominated in the past during ice ages.
5. Origin and termination	Originates at the end of the glaciers and terminates at the oceans.	Originates at the high mountain slopes and terminates at the mountain bases below the snowline.
6. Superimposition	Now, river valleys are superimposed on the past valleys by glaciers.	During the ice ages, glacial valleys were superimposed on the previous valleys carved out by rivers.

Question 31. Show with the help of a diagram any two landforms developed out of glacial action.
Answer: Landforms developed by glacial action

Class 10 Geography WBBSE

(1) Corrie and Arete: Corrie and Arete are the different types of features produced by glacial erosion. In the source regions of glaciers, in high mountain regions, glacial erosion causes a light depression to be eroded in such a way that the mountainside is steepened to form a headwall and at its foot, a pronounced depression is created by erosion.

When the glacier melts away in summer these resemble an armchair-like depression called Corrie in English and Cirque in French. Whereas, Arete is formed when glacial erosion may cause adjacent Corries to develop in the mountainside. The ridge that forms the boundary between the adjacent depressions is called Arete.

Question 32. Flow is the delta formed in the old stage of a river.
Answer: Near the mouth, at sea level, the main work of a river is the deposition of materials. Due to the heavy load of materials, the current of the river and its erosion action become weak and the accumulation of materials on the river bed is so high that the river is divided into many branches, forming islands between the two channels. This type of deposition resembles the Greek letter A and so is known as delta. Practically all the big rivers(e.g. Ganga, Nile, Mississippi, Missouri) have formed deltas. The delta of the Ganga is the largest in the world.

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Question 33. What are the differences between a Gorge& Canyon?
Answer:
1. Gorges are deep narrow valleys which look like the English letter’V’. Canyons, on the other hand, are very deep& extremely narrow, so they resemble the English alphabet T.
2. Gorges are formed due to high velocity in rivers of rainy mountain areas whereas Canyons are formed in dry regions ‘or deserts.
3. As Gorges are formed in areas receiving high rainfall, either bank gets eroded to give the shape V & many tributaries join from either bank. But canyons are mainly snowed and flow through semi-arid or dry areas.

Question 34. Differentiate between pediment and outwash plains.
Answer:
1. Pediment plains are produced by the work of wind, whereas outwash plains are produced by the work of glaciers.
2. Pediments are produced by wind erosion whereas outwash plains are produced by glacial deposition.
3. Pediments are slightly sloppy, dry, stony plains whereas outwash plain is covered with rocks, stones, pebbles, sand, etc. It is a levelled plain with snowmelt water flowing on the ground.

Chapter 1 Exogenic Processes And Resultant Landforms 5 Marks Questions And Answers:

Question 1. Describe with sketches three landforms carved out by glacial erosion.
Answer: The main landforms formed by erosion by glaciers are:

1. ‘U’ Shaped valley: The valley formed due to erosion on its bed and sides is called a ‘U’ shaped valley as it resembles the English alphabet ‘U’.

2. Corrie or Cirque: In the source region of the glacier, glacial erosion causes a’ depression in the rock bed, due to which the landform looks like an armchair. It is known as corrie or cirque. When it is filled with meltwater, it forms a cirque lake.

3. Hanging valley: Often the valley of a tributary glacier meets the valley of the main glacier. As the tributary glacier forms a smaller valley than the main glacier, it looks to hang above the main valley glacier. This valley of the tributary glacier is called Hanging Valley.

Question 2. Describe with sketches three major landforms developed by the erosional work of rivers.
Answer: The major landforms developed by the erosional work of rivers are described as follows:
1. V-shaped valley: The valley formed by a river in its upper course in which lateral erosion is greater than vertical erosion is known as a V-shaped valley as it resembles the English alphabet V. This valley is so narrow and the sides are so steep that gorges are formed.

Class 10 Geography WBBSE

2. l-Shaped valley: The valley formed by a river in its upper course in which vertical erosion is much greater than lateral erosion is known as an l-shaped valley as it resembles the English alphabet T. This valley is very narrow and very deep. It is also called Canyon.

3. Interlocking spur: A series of spurs lies between the banks of the river. As the main channel twists from side to side, so the spurs are described as ‘interlocking’.

4. Waterfalls: When a stream plunges down a very steep slope over a cliff, it forms a waterfall. India’s highest waterfall, Jog falls, (289.08 m) is on the river Sharavati.

Question 3. Describe with sketches the major landforms produced by Flavio-glacial deposition.
Answer: The landforms formed by glacial deposition are:

Class 10 Geography WBBSE

1. Moraines: Any landform formed by depositions of the valley and continental glaciers is called a moraine. The moraines can be mainly of three types:
(1)Moraines deposited alongside of glacial valley floor are called lateral moraines,
(2)Where two lateral moraines of adjacent glaciers combine, the deposition lying in the middle of the main glacier is called medial moraine,
(3)Moraines deposited at the end of a glacier are called terminal or end moraines.

2. Eskers: Long ridges of material deposited parallel to the direction of the flow of glacial melt water are called eskers. glacial meltwater is called eskers.
3. Erratics: These are depositions of boulders and rock fragments in an area where they are a total mismatch with the surroundings.

4. Drumlins: These are low elongated hills formed by glacial deposits. They are called ‘basket of eggs’ topography.

5. Karnes: These are small rounded hillocks of sand and gravel.
6. Outwash plains: These are materials washed out by glacial melt water and deposited in a variety of forms.

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Question 4. Describe with sketches the landforms developed by the combined action of wind and running water in the arid region.
Answer: The different landforms formed by the combined action of water and wind in a desert region are:

1. Wadi: In deserts, sudden torrential rains lead to the formation of valleys through which the collected rainwater may flow like a river. In the dry season, these valleys also remain dry.

2. Playa: Playas are small lakes found in deserts. They are highly saline and the water cannot be used for agricultural or household purposes.
3. Pediment: Pediment refers to the eroded and lowered plainlands that lie at the foot of the mountains.
4. Bajada: Bajada refers to the deposition of materials brought down by wind as well as water and deposited beyond the pediment.

Question 5. Describe the river’s erosional process and its different agents.
Answer: River erosion is accomplished in many ways, such as:
1. Hydraulic Plucking,
2. Abrasion or Corrasion,
3. Attrition and
4. Corrosion.

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1. Hydraulic Plucking: The force of moving water causes to sweep out of loose debris and particles from the river bed and channel walls, and carries the materials along in the current. These materials as carried by simple hydraulic action, range in size from clay to silt, sand, gravel and boulders.

2. Abrasion or Corrasion: Abrasion is the wearing away of the bed and banks using the load as the grinding tool. It is also called corrosion. It is the scouring action by the bedloads of rivers.

Types of Abrasion or Corrasion: The bed loads cause mechanical grinding as they knock, bounce, scrape and drag along the sides and bottom of the valley and break off additional rock fragments. The sideway erosion is called lateral corrasion. It widens the V-shaped valley. The downward erosion is called vertical corrasion. It deepens the river channel.

Potholes: Corrasion creates round holds called potholes, cylindrical holes carved into the hard bedrock of a swiftly moving stream. Potholes are deepened by spherical stones which are often found in the potholes. A spiralling flow of water in the pothole rotates the spherical stones at the base of the hole, boring gradually into the rock.

Plunge Pool: The plunge pool is another feature of the abrasion of a mountain stream. It is a deep pool cut out by the whirling round of boulders and stones at the base of a waterfall into which the water plunges.

3. Attrition: The pebbles, stones and boulders being carried by river currents do roll and collide with one another. They then transform into finer materials carried further downstream to be deposited. This attrition is the wear and tear of the transported materials themselves.

4. Corrosion: The chemical weathering of the rocks of the river bed and channel walls is called corrosion. Corrosion may be accomplished through solution and car- donation. Erosion by the dissolving action of fresh water, salt water, and acidic water is called corrosion.-The effects of corrosion are conspicuous in limestone, which develops cupped and fluted surfaces.

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Question 6. Describe the process of wind erosion.
Answer: The erosive power of the wind involves a triple process:
1. Deflation,
2. Abrasion and
3. Attrition.

1. Deflation: Deflation (Latin, “to blow away”) is similar to the plucking of a glacier or the hydraulic force of a river. As wind velocity increases, the surface materials lying loose are blown away. The finest ones lying loose on the surface, especially the dust, are picked up by the wind.

They are carried in suspension so long as the power of the upward currents of air exceeds the tendency of the suspended particles to fall to the ground. Generally, the wind blowing at a speed of about 16 km per hour picks up surface sand grains and transports them in suspension elsewhere.

In the suspension process, dust-like fine particles are picked up readily by the wind. Dust particles are transported to great distances and to great heights in the atmosphere. The heavier particles that are too big to be carried in suspension are bounded along the ground by the transportation process of Saltation (Latin: saltare, to leap).

Saltation makes sand grains hop, land and rebound, imparting fresh impetus to other surface particles and dislodging them. In the saltation process, the coarse sand grains are propelled by the wind. They hop, land and rebound. So sand grains are transported to short distances and maximum heights of 1.5 to 2.5 metres.

The surface particles of the ground dislodged by the saltation process are then driven forward on the ground as surface creep. In the surface creep process, small pebbles are made to roll forward with the momentum gained from jumping sand particles.

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Wind Load: Wind makes two types of load, such as
(1) Wind’s suspended load and
(2) Wind’s bed load. The surface particles carried in suspension by the wind make up the wind’s suspended load. The particles that bump and jump along the land surface make up the wind’s bed load. Wind load is used as cutting tools for abrasion by the wind.

2. Abrasion: The second process in which the wind erodes is abrasion. The wind-carried sand particles scratch, and polish the solid rocks. Particles carried by the wind strike obstacles such as rocks, boulders, etc. on their path. Such wind carrying a load can smooth and polish and groove rock surfaces. This activity of wind is called Abrasion (Latin ‘Scrape off).

Abrasion becomes highly forceful when the winds carry a load of hard quartz grains. After the initial weathering of rock surfaces through an excessive range of temperatures (annual and diurnal), the wind armed with rock fragments is capable to abrade. In their turn, the fragments created by abrasion are worn down by their attack which is formed like a sandblast on the solid rock against which they are blown.

Thus the process produces a great accumulation of rock debris. It is not possible for rock debris of all sizes to be transported. The pebbles and stones are not so readily removed as the fine sand. Wind can lift fine sand particles into the air and the abrasion action of the wind is the most effective within an altitude of a few metres above ground level as there is considerable frictional drag in the lowest layers of air.

In desert areas, fence posts and telephone poles are quickly cut through at the base by wind abrasion. So a protective metal sheathing or heap of large stones is placed around the base.

3. Attrition: Wind load is in a constant state of movement since it is being transported through processes like
(1) Suspension,
(2) Saltation and
(3) Surface creep.

These transportation processes involved in the gradual reduction in the size of pebbles as one rub against another are termed Attrition. More simply, attrition is the process by which different types of wind loads are reduced in size by rubbing against one another in course of their transportation by the wind.

Question 7. Describe the exogenetic processes active in producing landforms.
Answer: Exogenetic or Exogenous or External forces are those that work on the earth’s surface from outside and result in the formation of new landforms. These forces include. the shipments of the earth’s atmosphere, other agents of denudation and the formation of the force of gravity. They are essentially processes of destruction.

Agents of exogenetic processes: Exogenetic forces include running water, ground water, sea waves and shore currents, glaciers, periglacial processes, work of wind, weathering and mass movements, etc. Man along with plants and animals also acts as an exogenetic force.

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Processes: Exogenetic processes work through the processes of-
(1)Weathering,
(2) Mass wasting,
(3) Erosion,
(4) Transportation and
(5) Deposition. These start as soon as a newly created landform is exposed to the influence of weather.

Classification: The exogenetic processes can be classified as follows

1. Gradational Process
Definition: Gradational processes are continuously engaged in removing the vertical irregularities created by endogenous processes through denudational (both weathering and erosion) and depositional activities.

Agents of Gradational Process: The important agents of the gradational process are erosional, transportation and depositional works of running water or river, glacier, wind, groundwater and works of ocean waves and shore currents.

Process: Evidently, gradation involves three different processes:
(1)The process of wearing down (erosion) uplands,
(2)The process of transporting (transportation) the eroded materials,
(3)The process of filling up (deposition) lowlands.

Hence, Gradation = Erosion + Transportation + Deposition.
Types: It is clear that gradation is achieved by simultaneous action of the following three processes
(1) Degradation,
(2) Aggradation and
(3) Biotic Processes.

Associated Landforms:
(1) Flood plains,
(2) Formation of the delta,
(3) Moraine,
(4) Formation of stalactite and stalagmite,
(5) Loess, etc. are the important landforms created by the aggradation processes.

Biotic Processes: This includes the action of animals and insects, vegetation and man.

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2. Weathering
Definition: Weathering is the process that breaks rocks into smaller fragments by static agents of weather. It takes place in situ which means the rock fragments are found where they were formed originally.

Types: There are two major types of weathering
(1) Physical or Mechanical weathering and
(2) Chemical weathering.

3. Mass wasting
Definition: Mass wasting is the process of movement of soil or rock mass from one region to another mainly due to gravity. It can occur slowly or gradually (e.g. soil creep, or drastically, e.g. mudflow, rock slides).

Question 8. What are the reasons behind the location of the deserts?
Answer: About 1/3 rd of the world’s land is made up of deserts where the wind plays an active role in shaping the land. If you look at the world map, you will note that these deserts are more or less confined within a belt between 15° – 30° latitudes to the north and south of the equator. The reasons behind their location are:

1. These deserts lie mostly on the western part of the continents, where trade winds blow offshore and do not cause rain, e.g.: Sahara desert, Arabian desert, Iranian desert, Thar desert, etc.
2. Most of the deserts that lie in the coastal areas are influenced by the ‘desiccating effect’ of the cold ocean currents that prevent moisture to condense into precipitation. E.g.: Atacama desert (cold Peruvian current), Australian desert (West Australian current), etc.
3. In the mid-latitude temperate areas, deserts like Gobi, Takla Makan etc. lie in the continental interiors where there are extremes of temperature (continental climate). Winds lose any moisture that they may hold long before reaching the far-off continental interior.
4. The rainshadow effect produced by mountains also can create deserts. E.g.: Patagonia desert on the leeward side of Andes mountain, South America.

School Geography Class 10 WBBSE

Question 9. Suggest some measures to control desertification.
Answer:
Measures to control the expansion of the desert are:
1. Educating local poor people about the dangers of deforestation in order to stop it.
2. Employ the people to grow seedlings and transfer these too severely deforested areas during the rainy season,
3. Fixating soil by creating shelterbelts, windbreaks, etc. Windbreaks are made from trees and bushes that are planted across the path of the wind,
4. Anti-sand shields to resist the expansion of deserts to be created. Jojoba plantation is an effective anti-sand shield. This method is adopted in the Sahara desert,
5. Contour trenching, i.e., digging of trenches about 150 m long and 1 m deep to prevent water from flowing within the trenches causing erosion. Stone walls are to be created to prevent the trenches from closing up.
6. Sand fences can be used to control the drifting of soil and sand erosion,
7. Desert reclamation done by Farmer-Managed Natural Regeneration (FMNR) technique.
8. Managed intensive rational grazing for the restoration of grasslands is another method. Small paddocks with fences are to be used for grazing animals,
9. Creation of a plastic shield on the sand by sprinkling oil to prevent eroding away of sand particles,
10. Floodwater retention and infiltration and providing water for irrigation by canals dug from rivers of neighbouring regions.
(Indira Gandhi Neher in north Rajasthan provides water for irrigation in the Thar desert). Most of these measures have been adopted in the Sahara desert in Africa and the Thar desert of India for checking the expansion of the desert area.

Question 10. What are the effects of global warming on the region of Sundarbans?
Answer:
Effect of Global Warming on Sunderbans: Global warming on a large scale has affected the Sundarban region enormously. The effects of global warming are as follows:

1. Increasing temperature: The temperature of water in the Sundarbans has increased at an alarming rate of 0.5°C per decade causing harm to its aquatic life and the health of the mangrove forests. The span of the summer season has increased while that of the winter season has decreased.

2. Rising sea level due to the melting of ice sheets has led to the submergence of various islands in Sundar Moreover, the plants in the mangrove forests are becoming shorter and narrower with fewer branches resulting in lower rates of photosynthesis necessary for their regeneration.

3. Increase in the intensity and occurrence of cyclonic storms has become a serious problem. The occurrence of cyclone Aila in 2009 devastated the land.
4. Rise in the salinity due to a decrease in freshwater runoff has affected mangrove growth and soil fertility. So agriculture is also suffering from poor crop yield.
5. Due to global warming rainfall has become erratic and hence forced a change in agricultural patterns is causing low crop yield or crop failure.
6. The intrusion of saline water causes severe stress on the availability of drinking water also.

Question 11. Give an account of the current situation of Lohachara, New Moore and Ghoramara islands.
Answer:
Current situation of Lohachara Island: This island was permanently inundated in the 1980s due to a rise in the sea level probably as a result of global warming. It was an island located in the Hooghly river. It was an island located in the Hooghly river. It formed a part of the Sundarban delta before 1980. The definite disappearance of the island was reported by Indian researchers in December 2006.

It was an inhabited island with more than 6000 people. These people were forced to move to the mainland. Coastal erosion, cyclones, mangrove destruction and coastal flooding were considered as the other probable causes of its disappearance. In April 2009, however, the local Newspaper announced the re-emergence of the island from the waters.

Current situation of Newmoore or South Talpatti Island: South Talpatti (as was known in Bangladesh) or New Moore or Purbasha (India) was a small uninhabited island situated only 2 km from the mouth of Hariabhanga river in the coastal Bay of Bengal. An American satellite discovered the island in 1974. In March 2010, Sugata Flazra, an oceanographer at Jadavpur University of Kolkata, India, said that the island had disappeared due to sea level rise caused by climate change, changes in monsoon rain patterns and land subsidence.

Current situation of Ghoramara Island: Ghoramara island is located 150 km South of Kolkata, India, in the Sundarban delta complex of the Bay of Bengal. The island is only 5 sq km in area. Its existence is being threatened due to erosion and constant rise in the sea level and the total disappearance of this island in near future is apprehended.

School Geography Class 10 WBBSE

Question 12. What are the causes of desertification?
Answer:
Causes of desertification: According to Prof. Andre Goody of Oxford University, deserts extend due to various climatic and man-made causes. The gradual decrease in humidity and deterioration of land quality speeds up the process. Presently about l/6th of the total area of the world is under desert cover. The various causes of desertification are

1. Physical causes:

1)Drought: Regular and repetitive droughts in a particular area cause permanent damage to the soil. Vegetation cover is gradually lost and all ecosystems are destroyed.
2)Climatic changes: The greenhouse effect and global warming due to urbanisation, industrial growth, pollution, etc. affect the climate of the regions, which may speed up desertification.
3)Soil erosion: Removal of topsoil also causes desertification.
4)Presence of mountains: The presence of high mountains may stop moisture-laden winds to cause rainfall. Hence, deserts tend to grow in the rainshadow area.

2. Man-made causes:

1)Overgrazing: Overgrazing may remove the vegetative cover totally, causing permanent damage to the soil.
2)Over-cultivation: Over-cultivation may remove essential soil nutrients and bring about soil erosion.
3)Unscientific cultivation: Unscientific cultivation, especially in arid and semidesert areas, cause further extension of deserts.
4)Uncontrolled irrigation: Over-watering may cause some soils to become saline, hence loose fertility may tend to turn to deserts.
5)Deforestation: Cutting down trees removes the vegetative cover, causing desertification.

Question 13. Write in brief about the Sahara Desert.
Answer: The Sahara desert:

Location: The largest hot desert of the world, the Sahara lies in Africa over about 91,00,000 sq km area. It is bounded by the Atlantic Ocean in the west, the Red sea in the east, the Mediterranean sea in the north and the Niger river valley in the south. This desert lies over the countries of Algeria, Libya, Sudan, Chad, Tunisia, Mali, Morocco, Niger, etc.
Desertification: Satellite imageries show that the area of the Sahara desert is gradually increasing, especially towards the southern boundaries.

Reasons:
1. Extreme sand storms,
2. Lack of rainfall due to global warming,
3. Reduction of agriculture at border areas of the desert,
4. Occurrence of regular droughts.

Preventive measures:
1. The Federal State and the Govt, of Nigeria together have taken up annual tree-planting programmes. Free plants are distributed to be planted in agricultural fields and personal houses,
2. Heavy reforestation programmes are taken up in dry areas of Mali, Mauritania, Niger, Senegal, Chad, Ethiopia, Sudan, etc.
3. Involvement of students, ladies and the youth in reforestation and awareness programmes,
4. Spread of knowledge and awareness by students right from school levels,
5. In India the ‘van Mahotsav programme’ was taken up, by which thousands of trees were planted along roads, railway lines and hill slopes. The ‘Green Chattisgarh programme’ included the planting of robust trees with long life expectancies like teak and tamarind and fruit trees like mango and jackfruit in the dry regions.

School Geography Class 10 WBBSE

Question 14. Write in brief about the Thar desert.
Answer: The Thar Desert:

Location: The Thar desert spreads over 2.34 million sq km in India, covering west Rajasthan, Gujarat, southwestern Punjab and parts of Haryana.
Desertification: The region where the Thar desert lies today was known to be covered with vegetation in ancient times. The region was drained by the Saraswati and Yamuna rivers. Gradually due to geographical changes and human erratic actions the desert was created. The desert is extending still, and even the capital of Delhi may be engulfed one day.

1. High-speed winds,
2. Large moving sand dunes,
3. High diurnal range of temperature,
4. Low rainfall,
5. High rate of evaporation. The spread of gravelly soil in Jaisalmer suggests the existence of some mighty river in this region in the past. Evidence also shows that the desert extended outward in a big convex arc through Ferozepur, Patiala, and Agra towards Aligarh encroaching 130 sq km of fertile land every year.

Preventive measures:
1. Reforestation is being done on the hill slopes in this region according to several government programmes,
2. Artificial grasslands are being created to prevent the movement of sand dunes in Barmer, Jaisalmer, etc.
3. Trees that grow fast are being planted to meet the demand for fuel wood from local people in Jaisalmer, Jhunjhunu, etc.
4. The Rajasthan canal has been constructed to irrigate and reclaim infertile desert land.

Question 15. Give a brief description of three different landforms formed by the river in its lower course. Illustrate with diagrams.
Answer: In the lower course, near the mouth at sea level, the river loses all its strength and attains a stage of old age. At this stage, deposition becomes the main work and the river flows sluggishly; widespread deposition takes place and extensive flood plains are formed. The deposition is greater along the banks and on the mouth, and thus the following landforms are formed:

1. Flood plain: In the rainy season when a flood occurs, a widespread deposition of alluvium takes place. The depositions gradually fill up the low-lying areas of both the banks of a river and build up plains. These are known as flood plains. They are well-developed along the middle and lower course of the Ganga, Hwang Ho, Yangtze and other major rivers of the world. These flood plains are very fertile and densely populated.

2. Natural Levees: On the lower course of a river, active deposition takes place along the banks of an old river when it is in flood. Each time this happens, the banks get higher. After a long period of such deposition, the river banks are raised. These raised banks of the river are known as Natural Levees. Sometimes, the flood water breaks through these levees and brings devastating floods. Natural levees are found along the lower courses of the great rivers, such as, the Ganga, Hwang Ho and Yangtze.

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3. Deltas: Most of the load carried by a river is ultimately deposited into the sea into which it flows. The deposition, sometimes, builds up a fan-shaped alluvial cone which often looks like the Greek letter delta on its mouth and it is called delta. As deposition goes on in the river mouth, the river is forced to divide into several channels, each of which repeatedly divides.

All these channels are distributaries. Thus, a large number of distributaries are formed. The Ganga-Brahmaputra delta, the largest delta in the world, presents all these features.

Question 16. Write in short about the features mainly created by a river in its middle course.
Answer: The main features formed by a river in its middle course are

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1. Alluvial fan or Alluvial cone: As the river comes suddenly from its upper course to its middle course, its velocity decreases and its sediments are deposited along with the flow of the river resembling the shape of a cone or fan. This is known as Alluvial Fan.

(1)Widening valley: In the middle course of a river, lateral erosion predominates. The volume of water increases and the flow of water exerts its greatest force at the banks.

(2)Sand bars: The pebbles, sand, silt, etc. are deposited on the valley floor to form sand bars. Such bars are very common at the mouth of a river.
(3)Meander: In the middle course of river a because of the slackening of speed, a series of loops and bends are noticed. These bends are called meanders.

2. Oxbow lakes: During the meandering course of a river it often cuts through the curve to flow straight. Hence the left curve becomes a lake called ox-bow lake or horse-shoelace.

3. Flood plains and Natural levees: During the rainy season flood occurs in the river. So the water spreads out and deposits the sediment brought down and forms flood plains. On the bank of the river repeated deposit of silt or clay increases the height of the bank, forming natural levees.

4. Yazoo streams: During floods, levees may develop across the junctions of minor tributaries. Those tributaries are then compelled to follow a meandering course of their own until they find a new entrance in the main river. They flow roughly parallel to the main river in between the levees. Such rivers are called yazoos.

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Question 17. Describe the main erosional landforms formed by glaciers.
Answer: The main landforms formed by glaciers are

(1) ’U’ Shaped valley: The valley formed due to erosion on its bed and sides is called a ‘U’ shaped valley as it resembles the English alphabet ‘U’.

(2)Corrie or Cirque: In the source region of the glacier, glacial erosion causes a depression on the rock bed due to which it looks like an armchair. It is known as corrie or cirque. When it is filled with melt-water, it forms a cirque lake.

(3)Arete: Knife-edge ridge that is developed when the walls of two back-to-back corries have met after sapping from both sides, is called Arete or Serrated Ridge.
(4)Pyramidal Peak: Several aretes may meet at one point to make a peak known as Pyramidal Peak.

(5)Col: A col is a notch or a pass from where two cirques intersect to produce a deep saddle between high peaks.
(6)Hanging valley: Often the valley of a tributary glacier meets the valley of the main glacier. As the tributary glacier forms a smaller valley than the main glacier, it looks to hang above the main valley glacier. This valley of the tributary glacier is called Hanging Valley.

 

(7)Roche Moutonnee: These are hillocks of rock of a glaciated mountain which have been smoothened by the glacier on the upstream side, and left rough and rugged, with steeper slopes on the downstream side. They resemble sheep lying on the hillside and are also called sheep rocks.

(8)Crag and Tail: Along the path of a glacier if hard rocks and soft rocks lie one after another, the hard rocks protect the soft rocks from erosion by the glacier, so the hard rocks form a steep slope of a mountain called crag, while the soft rocks gently slope downwards to form a tail. This is called Crag and tail.

Question 18. Describe the aeolian depositional landforms with examples.
Answer: Depositional work of wind is geomorphological very important because significant features like sand dunes and loess are formed. Deposition of wind-blown sediments occurs due to a marked reduction in wind speed and obstruction caused by Pushes, forests, marshes and swamps, lakes, big rivers, walls, etc.

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Sand dunes are heaps or mounds of sand. There is a wide range of variations in the shape, size and structure of different types of dunes. They also vary in height and length. Dunes are classified on various bases-named morphology, structure, orientation, location etc.

1. Barkhans: Barkhan is a crescent or moon-shaped sand dune formed in a perpendicular direction to the wind. The windward side is convex and gentle while the leeward side is concave and steep. Its ends are called Horns. These resemble a Sickel or Bow. The sand dunes keep on advancing and many towns and vi buildings have been buried under these sand dunes.

2. Longitudinal dunes: These are long narrow ridges of sand. These lie parallel to the direction of the prevailing wind. They are sometimes hundreds of metres high. These are called Sief (meaning sword) in Sahara.

3. Transverse dunes: These are formed perpendicular to the wind. They look like large waves of sand. They are semicircular in shape.
4. Star dunes: The dunes having multiple slip faces, high central peaks, and radially extending three or more arms are called star dunes. Unlike other dunes, star dunes grow vertically and thus do not migrate laterally.

5. Whaleback dunes: The dunes formed of coarser sands left behind due to the migration of longitudinal dunes are called whaleback dunes. Very large whaleback dunes are called ‘dress’.
6. Head dune and Tail dune: Sometimes when there is an obstruction like a rock along the path of blowing wind, a sand dune gradually forms adjacent to the rock or the windward side, named a head dune. Another dune which forms on the leeward side is called a tail dune. The dune that forms just a little before the head dune is called an advanced dune and the dunes formed on both sides of the obstruction is called lateral dunes.

7. Loess: Loess is a wind-borne deposit. It is a yellow, porous, fertile deposit. The most extensive deposits are found in the N.W. China in Hwang-Ho Basin. It covers an area of 3 lakh sq. miles. Actually, the word ‘loess’ comes from such a deposit in a village of France.

Question 19. Compare the works of a river with those of a glacier.
Answer:

River	Glacier
1. Rivers arc the running water, rainwater or snow-melt water moving downwards along the slope of the land.	1. Glaciers are moving ice slowly come down because of the pull of gravity.
2. The rivers move faster than the glaciers and their erosive power is much more than that of glaciers.	2. The glaciers move slowly and their erosive power is less than that of the rivers.
3. Obstruction causes the river to form a meander.	3. Obstruction causes the glacier to remove or move over it.
4. The work of a river depends on the slope of the land, rock character and volume of water	4. The work of a glacier mainly depends on the volume of the glacier and the character of the rock over which it flows.
5. River valleys are V-shaped.	5. Glacier valleys are ‘U’- shaped.
6. The materials formed as a result of erosion due to river flow are rounded and smooth.	6. Materials formed due to glacial flow have no definite shape.
7. The course of a river can be divided into three stages: upper, middle and lower courses.	7. The course or path of a glacier can not be divided in such a manner.
8. The materials carried by a river are deposited according to the shape and size of the materials along the various stages of the river.	8. The materials transported by a glacier are deposited at any part of its valley and in various sizes.
9. Erosion by a river generally occurs through physical and chemical actions.	9. Glaciers only erode by physical action.
10. River erosion produces gorges, waterfalls, rapids, cataracts, potholes, V-shaped valleys, alluvial fans, etc.	10. Glacial erosion produces features like ‘U’- shaped valleys; corries or cirques, aretes, pyramidal peaks, hanging valleys, etc
11. River deposition produces flood plains, levees, deltas, braided channels, meanders, oxbow lakes, etc.	11. Glacial deposition produces moraines (lateral, medial, frontal), kames, drumlins, eskars, outwash plains, etc.
12. River action can be seen in all areas of the world except very cold and dry desert regions.	12. Glacier action can only be seen in the high mountains and in the very cold polar regions of the world.

Question 20. Describe the landforms formed due to aeolian erosion.
Answer:
1. Mushroom Rocks Sometimes the degree of hardness in the rocks varies considerably. Due to differential abrasion, the softer rock is worn out more easily than the harder rock and the under-cutting on the base is more than on the top forming narrow rock. The rock resembles the like of an elephant or camel or another animal. Local names are given to this type of rock such as Mushroom rock or Gour.

2. Zeugen When the wind blows steadily in one direction for a considerable time due to differential abrasion, the wind wears away the underlying softer rock through the joints (caused by mechanical weathering). The harder rock layer stands uneroded and stands like ridges. This is known as Zeugen. They are of varying heights (from 1.5 m to 45 m).

3. Yardangs: Yardangs are one of the various landform features developed out of aeolian erosion in desert regions. When hard and soft rocks are arranged vertically on the earth’s surface, then the soft rocks get quickly eroded forming long valleys while the hard rocks stand out as ridges called Yardangs. These are generally 15 metres high and are found in the deserts of Central Asia.

Sometimes hard and soft rocks stand parallel to the prevailing winds. Due to abrasion soft rocks are worn away and the hard one stands as stony ribs. The whole area resembles ‘furrow’ or ‘ridges’. This phenomenon is known as ‘Yardang’. This is common in the Atacama desert.

4. Inselberg: Inselbergs are very highly resistant hard rock structures formed due to wind erosion. They are found in desert areas and are of usually the same height. They have a flat-topped surface with steep slopes.

 

Geography Class 10 West Bengal Board India – Climate Of India Multiple Choice Type:

Question 1. “Burst of Monsoon” is first observed in:
1. Kerala
2. Karnataka
3. Maghalaya
4. West Bengal

Answer: 1. Kerala

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 2. Western disturbances occur in India during:
1. Summer season
2. Autumn season
3. Rainy season
4. Winter season

Answer: 2. Winter season

Question 3. Dust storms of North-West India in summer are called:
1. Kalbaisakhi
2. Andhi
3. Westem disturbance
4. Loo

Answer: 2. Andhi

Question 4. ______ receives highest rainfall.
1. Mousinram
2. Kerala
3. Andhra Pradesh
4. Orissa

Answer: 1. Mousinram

Geography Class 10 West Bengal Board

Question 5. ______ is common in West Bengal.
1. Kalbaisakhi
2. Western disturbance
3. Hurricanes
4. Landslides

Answer: 1. Kalbaisakhi

Question 6. Winter rainfall in India is caused due to
1. Cyclones
2. South-West Monsoon
3. Hurricanes
4. North-East Monsoon

Answer: 2. South-West Monsoon

Question 7. The State of Assam falls in the region ______.
1. Heavy rainfall
2. Moderate rainfall
3. Light rainfall
4. None

Answer: 1. Heavy rainfall

Question 8. Monsoons are ______ winds.
1. Local
2. Seasonal
3. Permanent
4. Casual

Answer: 2. Seasonal

Question 9. The place that gets rainfall from the western disturbances is _____.
1. Srinagar
2. Mumbai
3. Ahmedabad
4. Orissa

Answer: 3. Ahmedabad

Question 10. The place which has the lowest mean temperature in January is ______.
1. Kolkata
2. Lucknow
3. Srinagar
4. Chennai

Answer: 3. Srinagar

Question 11. Excessive heavy rainfall occurs in _______.
1. Andhra Pradesh
2. Meghalaya
3. Punjab
4. Orissa

Answer: 2. Meghalaya

Question 12. Local winds which bring thunderstorm are _____.
1. Loo
2. Andhi
3. Nor’westers
4. Cyclones

Answer: 3. Nor’westers

Question 13. Desert and semi-desert condition prevails in _____.
1. Karnataka
2. Rajasthan
3. Kerala
4. Arunachal Pradesh

Answer: 2. Rajasthan

Question 14. Maximum temperature occurs in:
1. Cherrapunji
2. Bermer
3. Bhopal
4. Delhi

Answer: 2. Bermer

Question 15. Deccan Plateau is a _____ region.
1. Rainshadow
2. Heavy rainfall
3. Mountainous
4. Plain area

Answer: 1. Rainshadow

Question 16. The _____ experiences rainfall twice.
1. Malabar coast
2. Konkancoast
3. Coromondel coast
4. None of the above

Answer: 3. Coromandel coast

Geography Class 10 West Bengal Board

Question 17. The western coastal plain receives blows from rainfall
1. Low
2. High
3. Moderate
4. Normal

Answer: 2. High

Question 18. The monsoon wind during summer blows from ______ direction in India.
1. South-east
2. North-east
3. South-west
4. East-west

Answer: 3. South-west

Question 19. The north-western part of India has
1. Extremes of climate
2. Moderate climate
3. Wet climate
4. None of the above

Answer: 1. Extremes of climate

Question 20. The highest rainfall in India is recorded at
1. Baxadoars
2. Cherrapunji
3. Mousinram
4. None of the above

Answer: 3. Mousinram

Question 21. The interior part of the Deccan Plateau is situated in the _____ side of the Western Ghats.
1. Leeward
2. Windward
3. Western side of the western ghats
4. None of the above

Answer: 1. Leeward

Question 22. Loo is a
1. Hot wind
2. Cold wind which mainly blows over U.P.
3. Savannah
4. None of the above

Answer: 1. Hot wind

Question 23. Andhi is a:
1. Dust storm
2. Cold wind which flows during summer month
3. Hot wind
4. None of the above

Answer: 1. Dust storm

Question 24. ______ is common in West Bengal.
1. Kalbaisakhi
2. Western disturbance
3. Both of these
4. None of these

Answer: 1. Kalbaisakhi

Question 25. Winter rainfall in India is caused due to
1. Cyclones
2. S.W.Monsoon
3. Both of these
4. None of these

Answer: 1. Cyclones

Geography Class 10 West Bengal Board

Question 26. Excessive heavy rainfall occurs in
1. Meghalaya
2. Andhra Pradesh
3. Punjab
4. West Bengal

Answer: 1. Meghalaya

Question 27. Local winds which bring thunderstorms are
1. Loo
2. Andhi
3. Mango Showers
4. Nor-westers

Answer: 4. Nor-westers

Question 28. Maximum rainfall occurs during the month of
1. July-August
2. May-June
3. January-March
4. September-October

Answer: 1. July-August

School Geography Class 10 WBBSE India – Climate Of India True Or False Type:

Question 1. Monsoon is an Arabic word.
Answer: True

Question 2. India is a land of monsoons.
Answer: True

Question 3. South-West Monsoon causes heavy rainfall.
Answer: True

Question 4. Coromandel Coast receives rainfall twice in a year.
Answer: True

Question 5. Heavy rainfall causes floods.
Answer: True

Question 6. There are mainly 4 seasons in India.
Answer: True

Question 7. South-West Monsoon brings rainfall in India.
Answer: True

Question 8. Tamil Nadu Coastal plain receives rainfall in the winter season.
Answer: True

Question 9. Nor’wester blows in West Bengal.
Answer: True

Geography Class 10 West Bengal Board

Question 10. Western disturbance is common in the North—Western States of India.
Answer: True

Question 11. A rain shadow area in India is Pune.
Answer: True

Question 12. The actual period of the South-West Monsoon is January to March.
Answer: False

Question 13. The rainfall of India is evenly distributed.
Answer: False

Question 14. March is the hottest month of summer in India.
Answer: False

Question 15. Seasonal heavy rainfall and drought are common features of the monsoon climate in India.
Answer: True

Question 16. High-pressure condition prevails on the Indian Ocean in summer.
Answer: True

Question 17. Rainfall is heavy on the eastern side of the Western Ghats.
Answer: False

Question 18. Dust storm in Western India is called Loo.
Answer: False

Question 19. The hot wind blowing over the U.P. during summer months is called Loo.
Answer: True

Question 20. Mango Showers are experienced in Tamil Nadu.
Answer: True

Question 21. Deccan Plateau is a rain shadow region.
Answer: True

Question 22. Thar desert receives scanty rainfall.
Answer: True

Geography Class 10 West Bengal Board

Question 23. Seasonal rainfall and drought are common features of the monsoon climate of India.
Answer: True

Question 24. High pressure condition prevails in the Indian Ocean in summer.
Answer: True

Question 25. Rainfall is heavy on the leeward side of the Western Ghats.
Answer: False

Question 26. The north-western part of India has a very low-pressure centre during summer.
Answer: True

Question 27. The western part of India has a very low-pressure centre during summer.
Answer: False

Question 28. The western disturbances bring rainfall and coldness during summer.
Answer: True

Question 29. Winter rainfall in India is very common.
Answer: False

Question 30. The coastal region has extremes of climate.
Answer: False

Question 31. The climate of India is hot, arid and monsoon-type.
Answer: False

Geography Class 10 Solutions WBBSE India – Climate Of India Fill In The Blanks Type:

Question 1. The dust storms developed during summer seasons in North-West India are known as ______.
Answer: Andhi.

Question 2. ______ is a hot dry wind found in India.
Answer: Loo.

Question 3. Monsoon means ______ or Season.
Answer: Mousom.

Question 4. _____ means Inter Tropical Convergence.
Answer: ITC.

Question 5. ______ receives the highest rainfall in India.
Answer: Mausinram.

Geography Class 10 West Bengal Board

Question 6. Monsoon is an Arabic word meaning _____.
Answer: Season.

Question 7. Deccan Plateau is a rain ______ region.
Answer: Shadow.

Question 8. Mousinram receives the highest in India.
Answer: Rainfall.

Question 9. ______ is a desert because of scanty rainfall.
Answer: Rajasthan.

Question 10. _____ coast receives rainfall twice in a year.
Answer: Coromandel.

Question 11. ______ is a storm experienced in W.B.
Answer: Kalbaisakhi.

India – Climate Of India Very Short Answer Type:

Question 1. Which region in India experiences rainfall twice in a year?
Answer: The Coromandal coast (Tamil Nadu coast).

Question 2. Name a region where snowfall occurs.
Answer: Kashmir Himalaya.

Question 3. Name the place recording the lowest temperature in India
Answer: Dras or Kargilin J & K.

Question 4. Name an important area of winter rainfall in south India.
Answer: Tamil Nadu.

Question 5. Give an important area receiving rainfall from the western disturbances.
Answer: North-West India.

Question 6. Name two areas receiving annual rainfall below 20 cm.
Answer: The western extremity of Rajasthan and the region in the north-east of Ladakh range in J & K.

Question 7. Name the ranges which receive the heaviest rainfall.
Answer: Western Ghats and Meghalaya plateau.

Question 8. What do you mean by the word monsoon?
Answer: Monsoon is an Arabic word. It means season.

Question 9. Name one rainshadow region of India.
Answer: The eastern slopes of the Eastern Ghats of the Deccan Plateau.

Question 10. Which wind controls the rainfall in India?
Answer: South-West Monsoon Wind.

Question 11. Which region of India receives scanty rainfall?
Answer: Western India (Thar Desert).

Question 12. Name the winter months of India.
Answer: December to February.

Geography Class 10 West Bengal Board

Question 13. Name the rainy months of India.
Answer: June to September.

Question 14. Name a rainshadow region of India.
Answer: Karnataka Plateau.

Question 15. Which place in India records the highest rainfall?
Answer: Mousinram.

Question 16. Mention the factors affecting the Indian climate.
Answer: The main factors affecting the Indian climate are:
1. Relief,
2. Temperature,
3. Nearness to sea,
4. Continentality,
5. Presence of forest,
6. Humidity.

Question 17. What is a rainy day?
Answer: A rainy day in India is defined as one in which at least 2.5 mm of rain has been gauged in 24 hours.

WBBSE Class 10 Geography Solutions India – Climate Of India 2 Marks Questions And Answers:

Question 1. What is Western Disturbance?
Answer: During the winter season cyclonic disturbances come from the Mediterranean region. They enter India from the northwest and give some rainfall to the North Western India, Gangetic plains and snowfall in the Himalayan region. These depressions coming from the west disrupt the quiet weather in winter and, therefore, are called Western Disturbances.

Question 2. What is ‘Kal Baishakhi’?
Answer: In summer rainfall is not high. Various parts of the country have local low pressures which bring in strong winds together with rainfall, thunder and lightning. Such storms are called ‘Kal Baisakhi’ in West Bengal.

Question 3. Why dies Kolkata experience the hot-most weather in summer?
Answer: During summer, S.W. Monsoon winds blow which bring water from the Indian ocean. Hence it gives rainfall in summer. Thus; Kolkata experiences hot moist weather in summer.

Question 4. What is the rainshadow area?
Answer: When moisture-laden winds come in contact with a mountain, they give rainfall to the windward side. On the leeward side, as the air descends, its temperature increases, the winds become compressed and warmed adaptively at the dry lapse rate which is rapid. As the winds descend, they become drier and drier resulting in very small rainfall or no rainfall. This leeward side is known as the ‘rainshadow area’.

Question 5. What is meant by ‘burst of monsoon’?
Answer: The southwest monsoon in India is noted for its dramatic arrival with a rainy spell of weather continuing for some days. It is called the ‘burst’ which takes place by the end of May in Kerala, and by the 7th of June in West Bengal. By July the whole of India is brought under the influence of monsoon.

Question 6. Why does Tamil Nadu coast receive rainfall twice a year?
Answer: Most of the rain by the S.W. monsoon falls on the western coast of India in the summer season and on the Tamil Nadu coast
the amount of rainfall is not much. But in the winter season, N.E. monsoon winds blow. When they cross the Bay of Bengal, they are full of water vapour and moisture. As a result, they give rain to the coast in winter.

Question 7. Why is the ‘Kalbaishakhi’ called ‘Nor’wester’?
Answer: Nor’westers are violent local storms. They often form during the summer in regions where deep humid clouds from the seas meet hot dry land winds. They are called Nor’westers because the storms usually come from the northwest, and they are known in Bengal as ‘Kalbaisakhi’, i.e., calamity in the month of Baisakh. These storms are accompanied by violent winds, torrential rain and hail. Very dry sandstorms of western India, called Andhi are also called Norwesters.

Class 10 Geography West Bengal Board

Question 8. Where is the highest rainfall region of the world located?
Answer: Mousinram (near Cherrapunji) in India receives the highest rainfall in the world. It is located in Meghalaya state.

Question 9. Why does the winter season in India experience dry weather?
Answer: During winter N.E. Monsoon winds blow which come from land. Hence they are very dry. This winter season in India experiences dry weather.

Question 10. What is ‘Mango Showers’?
Answer: In summer due to the formation of local low pressure, strong winds together with rainfall, thunder, lightening occur in parts of South India, This weather phenomenon is called ‘Mango Showers’.

Question 11. What is Loo?
Answer: In the month of May the temperature rises as high as 48°C in the desert region of India. This high temperature causes a hot, dry wind to blow during the daytime over north-western India. This wind over the Gangetic plain is called Loo.

Question 12. What is ‘Andhi’?
Answer: During summer months the desert of Rajasthan gets intensely heated. The high temperature causes a hot dry wind to blow during day time over north-western India. In Rajasthan, it is called ‘Andhi’.

Question 13. Mention three regions which receive rainfall of more than 200 cm annually.
Answer: The regions receiving rainfall more than 200 cm annually in India are:
1. Western slopes of the Western Ghats,
2. Eastern Himalayas – Mizoram, North Bengal And
3. Andaman & Nicobar groups of islands.

Question 14. What is the meaning of the term ‘Monsoon’?
Answer: During summer most wind from south-westerly directs blows almost all over India which brings rain & during winter dry north-easterly winds blow. These reverse winds are monsoon. The word monsoon has been derived from the Arabic word ‘Mausam’ which means season as monsoon is a seasonal wind.

Question 15. Explain why Delhi is rainier than Jodhpur.
Answer: Arabian sea branch of the monsoon moves over the Acer of Rajasthan where Jodhpur is located without giving rain because of extreme aridity. The Aravallis lie parallel to the wind direction of $.W. monsoon because of which winds moving over this area give only scanty rain. On the other hand, Delhi gets moderate rain as the Arabian sea branch of the monsoon meets the Bay of Bengal branch. These two branches jointly. cause moderate rainfall in this area.

Question 16. Name two states where ‘mango showers’ are a common phenomenon.
Answer: ‘Mangoshowers’ are commonly experienced in the states of Kerala and Andhra Pradesh.

Question 17. When the Malabar coasts receive heavy rainfall in July, the Tamil Nadu coast is comparatively dry. Critically analyse the statement.
Answer: The southwest monsoons cause heavy rainfall on the Malabar coast after striking against the Western Ghat but Tamil Nadu does not receive much rainfall because it is situated in the rainshadow area.

Class 10 Geography West Bengal Board

Question 18. The coastal areas of India do not experience significant variations in temperature between the summer and winter months.
Answer: The coastal areas do not experience much variation in temperature because they are influenced by the moderating effect of the sea.

Question 19. Name two types of cyclonic systems that affect the Indian sub-continent and two areas that receive rainfall from these systems.
Answer: Tropical cyclones in coastal areas of the Indian sub-continent and western disturbances in northwest India and Pakistan.

Question 20. Name the two branches of the South-West Monsoon.
Answer: Arabian Sea Branch and the Bay of Bengal Branch.

Question 21. Name two states receiving Mango Showers in India.
Answer: Kerala and Karnataka/Tamil Nadu.

WBBSE Class 10 Geography Solutions India – Climate Of India Short Notes:

Question 1. Western disturbance.
Answer: In winter weather is characterised by clear skies, high pressure, low humidity and rainless days. However, this fine weather in India is occasionally disturbed by cyclonic depressions. These weather disturbances originate in the east Mediterranean region and travel eastwards across Iran and Pakistan. They bring rain in areas of Jammu and Kashmir, Punjab, Himachal Pradesh, Haryana, Rajasthan and U.P. Sometimes they invade up to West Bengal. They also cause rainfall in North-Western Himalayas. As these winds come from the West, they are popularly known as Western Disturbances. They are very frequent in December, January and February.

Question 2. Ashwiner Jhar.
Answer: As the southwest monsoon retreats, the northeast monsoon winds approach and they collide, resulting in the formation of cyclones, particularly known as ‘Ashwin Jhar’ or the storms of the autumn. They give some rain. Sometimes these cyclones get the such speed and velocity that they become devastating and they cause great havoc to life and property. They caused havoc in Bangladesh in 1970, in Andhra in 1977, and in Orissa in 1999.

Question 3. Nor’westers.
Answer: In summer, North India is a region of rising temperature and decreasing air pressure. Air over the heated Indian landmass rises and slowly air from the adjoining cooler seas moves in to fill the vacuum. Violent local storms accompanied with thundershowers and hail are common in North India in the months of April and May.

Class 10 Geography West Bengal Board

In Assam and West Bengal, there are thunderstorms called ‘Kalbaisakhi’ or “Nor’westers’. ‘Kalbaisakhi’, i.e., calamity in the month of Baisakh. They are called ‘Mango Showers’ in Kerela, ‘Bordoichillah’ in Assam, ‘Cherry Blossoms’ in Karnataka – and Tamil Nadu.

Question 4. Vagaries of Monsoon.
Answer: About 70% of the population of India depends on agriculture, which in its turn, is primarily controlled by the rainfall caused by the South-West monsoon. Droughts and floods are two contrasting features of the summer monsoon seasons in India. They frequently occur in one part of the country or the other and in one year or the other. A weak monsoon in a year causes drought in many areas, especially in drought-prone areas in North-West India, whereas a strong monsoon in some other year causes floods in many rivers from excessive rainfall. It may be mentioned here that a normal feature of the summer monsoon in India is the occurrence of rainy spells of weather with intervening drier weather conditions. If, however, a dry spell persists too long, drought may also occur even in years of normal rainfall in amount and causes crops to wither in the field. So, if rain does not fall timely and in requisite amount, agriculture is greatly affected causing great distress to the people of India.

Question 5. El-Nino.
Answer: El-Nino is a warm surface ocean current which appears off the coast of Peru in South America. It is a temporary replacement of cold Peruvian current flowing along that coast. It happens to increase the temperature of tropical Pacific waters by about 10°C causing flood and drought in the tropical regions of the world. India lying in the tropical region also experiences such flood or drought situations due to its effect.

WBBSE Class 10 Geography Solutions India – Climate Of India 3 Marks Questions And Answers:

Question 1. Cherrapunji-Mousinram receives the highest rainfall in the world. Why?
Answer: Mousinram is in the Meghalaya Plateau. It is the wettest place in the world. The orographic feature of the Meghalaya Plateau has a pronounced effect in making it the wettest part of India.

Mousinram, situated about 16 km west of Cherrapunji, records the highest rainfall in the world, averaging 13,924 mm. That this highest rainfall occurs in the Cherrapunji Mousinram region is due to the fact that the Bay Monsoon, laden with a huge amount of moisture from the Indian Ocean and Bay of Bengal, blows over Bangladesh and is suddenly cut by the cliffs of the highland in the North about 1200 m which just like a peninsula into the surrounding gorge about 600 m deep on either side. The topography causes the monsoon winds reaching the head of the gorge to ascend vertically upwards and pour down very heavy rainfall.

Class 10 Geography West Bengal Board

Question 2. Why are floods and drought prevalent in India?
Answer: Cause of prevalence of floods:
1) An early and heavy monsoonal rain (causes floods mainly in Assam).
2) A prolonged rainy season.
3) continuous rain throughout the rainy season (causes floods in Bihar and West Bengal).

Apart from these physical reasons, some socio-economic reasons are also important.
(1) Heavy siltation at the artificial reservoirs.
(2) Urban and industrial development that retards the natural flow of rivers.
(3) Less infiltration and increased surface flow of rainwater.

Causes of the prevalence of drought:
(1) A delayed monsoon.
(2) A short duration of the rainy season.
(3) Long intervals among rains.

The socio-economic reasons are:
(1) Over-exploitation of groundwater.
(2) Deforestation.
(3) Global Warming.

Question 3. Name the climatic regions of India.
Answer: The climatic regions of India are as follows:
1. Tropical very humid monsoon.
2. Tropical Savanna.
3. Tropic with dry summer & humid winter region.
4. Tropical, Semi-arid & sub-tropical, Steppe region.
5. Hot desert region.
6. Temperate with short summer & cold humid region.
7. Humid tropical monsoon region with dry winters.
8. Cold mountain type of climate region.

School Geography Class 10 WBBSE

Question 4. Mention the influence of monsoon climate on Indian Life.
Answer:
Monsoon plays a dynamic role in Indian life:
1. Success of agriculture depends on the good yield of Kharif food crops and cash crops, like Rice, sugarcane, cotton, tea, jute, etc. Winter crops also depend on monsoon rain, like Wheat, barley, pulses, oilseeds, etc.
2. Development of agro-based industries has an indirect influence on monsoon. Good yield of cash crops supports the agro-based industry as well as they are foreign exchange-earners.
3. Forest growth: the vast resource of tropical evergreen, as well as deciduous forests, is the gift of monsoon.

Question 5. Give at least three important reasons why the western part of Rajasthan remains almost dry during the South-West monsoon season.
Answer:
1. This area is located far away from the moderating influence of the sea.
2. The Aravallis are parallel to the S. W. monsoon winds & fail to obstruct these winds.
3. Since the area has poor vegetation, it is not conducive to precipitation.
4. Hot and dry condition leads to retardation of precipitation.
5. The Bay of Bengal branch of the monsoon becomes dry till it reaches this area.

Question 6. Why is the distribution of rainfall in India uneven? Give at least three reasons.
Answer: Causes of Uneven Distribution of Rainfall in India:
India is a huge country. It gets its rainfall mainly from the South-West monsoon. These are, however, governed by relief or orography.

Therefore, the causes of the uneven distribution of rainfall are:
1. The Arabian sea branch of the monsoon is obstructed by the Western Ghats. The windward side of the Sahyadris receives very heavy rains (over 250 cm, however, the seaward side is hardly able to receive 50 cm).
2. Another part of the Arabian sea branch strikes the Saurashtra peninsula and the Kutchchh. It passes over west Rajasthan & along the Aravallis causing only a scanty rainfall. This is because there is no obstruction on their path as Aravallis lie parallel to the winds.
3. The Bay of Bengal branch enters West Bengal and Bangladesh and splits into two. One branch moves up the Brahmaputra valley in the north and northeast causing rains in North-eastern India. Therefore, it causes heavy rains in Garo and Khasi hills andCherrapunji.

Question 7. Why is there a large desert in Rajasthan?
Answer: The influence of the Arabian Sea Branch scarcely reaches north of the Gulf of Khambat; further north, a part of these winds passes over the desert of Rajasthan and goes straight to the foothills of the Himalayas without giving any rain.
The Aravalli Range lies almost parallel to the direction of the wind. Hence, it gives no obstruction, and that is why no rainfall occurs. Again, the feeble Bay of Bengal current which reaches western Rajasthan fails to produce any rain. Thus western Rajasthan remains almost rainless presenting the Thar desert.

School Geography Class 10 WBBSE

Question 8. What is the Inter-Tropical Convergence Zone (ITCZ)? How does it attract southwest monsoon?
Answer: This is the zone near the equator where northeast trade winds from the northern hemisphere and the southeast trade winds from the southern hemisphere meet each other. It changes its position with the march of the vertical rays of the sun. It is near the Tropic of Cancer in the north in summer season and near the Tropic of Capricorn in the south in the winter season. It is at about 25°N latitude in summer, as a result of which the southeast trade winds cross over the equator and enter India as southwest monsoon.

Question 9. Give three important characteristics of the summer monsoon rainfall.
Answer:
1. Seasonal rainfall.
2. Uncertain and unreliable rainfall.
3. Uneven distribution of rainfall.

Question 10. Name the rainiest and driest parts of India. Why are they so?

Answer: Mausinram near Cherrapunji with 1221 cm of annual rainfall is the rainiest part of India. The southwest monsoon winds reach Garo, Khasi and Jaintia hills and have to rise suddenly because the hills are funnel-shaped. This causes heavy rainfall. The driest part is Jaisalmer in Rajasthan. This is due to its location far away from the sea.

Question 11. Give five examples with reference to the distribution of rainfall and the effect of relief on its distribution.
Answer:
1. Heavy rainfall on the west coastal plain due to the Western Ghats.
2. Low rainfall in the rain shadow area of the Western Ghats.
3. Heavy rainfall in Meghalaya due to the slope of the hills.
4. Low rainfall in Rajasthan due to the direction of the Aravalli Range.
5. Effect of the Himalayas on the direction of the monsoons.

Question 12. Rainfall decreases as one goes up the Ganga plain. Why?
Answer: After heavy rainfall in the eastern Himalayan region, the monsoon wind takes a left turn and blows towards the west. On its way rainfall occurs. But the percentage of water vapour decreases and rainfall also decreases. Eastern India receives 200 to 300 cm of rainfall, but northern India receives only 50 to 70 cm rainfall.

School Geography Class 10 WBBSE

Question 13. Write the features of rainfall in India.
Answer: Features of Rainfall in India:
The main features of the rainfall in India are:

1. There is rainfall over three months and the rest of the year is mostly dry. Seventy per cent of the annual rainfall occurs in the rainy season.
2. The rains are mainly of relief type. The windward slopes of the mountains get more rainfall than the leeward side.
3. Only a small portion of the rainfall is received from sources other than monsoons, like cyclonic rainfall and convectional rainfall.
4. The quantity and the time of occurrence of rainfall cannot be predicted as the rainfall is erratic. It is because of this uncertainty that sometimes there are floods; and sometimes droughts.
5. India has an agrarian economy dependent on rainfall. As such rainfall affects the economy of the country.

Question 14. Give an account of the areas which receive rainfall in the winter season.
Answer: There are some areas which do receive rainfall in the winter season. They are:
1. Central parts of India and northern parts of the southern Peninsular region get occasional rainfall in winter.
2. Some weak temperate cyclones from the Mediterranean sea cause rainfall in Delhi, Haryana, Punjab and western Uttar Pradesh. Though the amount of this rainfall is meagre, it is quite beneficial for the rabi crops.
3. The northeastern part of India also gets rainfall during the winter months. Arunachal Pradesh and Assam get rains between 25 mm and 50 mm during winter.
4. In the months of October and November, the north-east monsoon while crossing over the Bay of Bengal, picks up moisture and brings torrential rainfall over parts of Andhra Pradesh, Karnataka, Kerala and Tamil Nadu coast.

Question 15. Distinguish between the Arabian Sea branch and the Bay of Bengal Branch of South-West Monsoon winds.
Answer:

Question 16. ‘Temperature in India varies from place to place’. Comment.
Answer: Seasonal variations in temperature occur from place to place and from region to region. Variations in temperature are found also at a single place and in a single day. Examples of these variations are:

School Geography Class 10 WBBSE

1. Barmer in Rajasthan may record a temperature of 48°C or 50°C on a June day, while it hardly reaches 22°C at Pahalgam or Gulmarg in Kashmir on the same day.
2. Kerala has a tropical climate with warm and moist air, whereas Punjab has continental climate with severe heat alternating with a severe cold.
3. The temperature touches —40°C in Kargil in the month of December whereas Kerala records 20°C or 22°C in the same month.
4. Temperature rises up to 50°C in Rajasthan during summer while in Dras near Kargil, the temperature may go down to —40°C during winter.
5. The annual range of temperature is 3°C along the Malabar Coast and more than 20°C in the interiors.
6. The difference between day and night temperatures in the Andaman Islands and Kerala is hardly seven or eight-degree celsius, whereas in the Thar desert it is between 25 to 30°C. at

Question 17. Explain the difference in the type and content of precipitation across India.
Answer: Variations occur not only in the type of precipitation but also in its amount. Snowfall occurs in the Himalayas, whereas it only rains over the rest of the country.
1. Cherrapunji and Mausinram in Meghalaya get about 1100 cm rain over the year, whereas Jaisalmer in Rajasthan hardly receives 9:cm of rainfall in a year.
2. A place called Tura in Meghalaya gets an amount of rainfall in a single day which is equal to 10 years of rainfall at Jaisalmer in Rajasthan.
3. The Coromandal Coast remains dry in the months of July and August, whereas the Ganga delta and the coastal plains of Orissa are hit by strong storms almost every third or fifth day during these months.
4. Most parts of India receive rainfall during June-September, but the coastal areas of Tamil Nadu also get rains in the beginning of the winter season.

Question 18. What are the features of Indian climate?
Answer: Features of Indian Climate:
1. Tropical monsoon type of climate.
2. Diversity in climatic conditions.
3. Monsoon mechanism dominates the climate.
4. Presence of four distinct seasons in the year.
5. Tropical depressions or Bay cyclones in late monsoons.
6. Westerly depressions causing rainfall in winter in North India.

Question 19. State some characteristics of monsoon.
Answer: Characteristics of Monsoon:
1. Monsoons are erratic in nature.
2. Monsoons are unevenly spread and sporadic.
3. Monsoon rains are orographic in nature.
4. Monsoons bring rain in summer.
5. Monsoon rains determine the economic state of the country by controlling agricultural prosperity.
6. Some of the rain occurs due to tropical depressions.

Question 20. Explain briefly three effects of climatic changes observed in the Sundarban region.
Answer: Global warming and climate change compound the dangers to the Sundarbans. These low-lying mangrove forests are highly susceptible to the effects of sea-level rise-including inundation of coastal areas, increased exposure to storm surges, in- creased coastal erosion, and rising salinity in ground and surface waters.

Geography Class 10 Solutions WBBSE

Question 21. Write the impact of monsoon rainfall on soil, natural vegetation, and agriculture.
Answer: Monsoonal climate is primarily evident in tropical countries like India where more than 75% of the annual rainfall is caused by monsoons. Removal of the top soil layer is caused by heavy downpours. The top soil retains plant nutrients and hence agricultural productivity. suffers when there is soil erosion. The luxuriant growth of evergreen vegetation is noticed in areas of heavy rainfall. Dry deciduous forests grow in the rainshadow areas of the Deccan plateau. Little rainfall in the north-western part of India has produced a desert there with thorny scrubs and stunted trees. The impact of monsoon is mostly felt in the agricultural fields as our cropping season entirely depends on the timely arrival and departure of monsoon. This whimsical nature of monsoon causes disruption of regular cropping seasons and affects agricultural yield. Sometimes heavy rainfall leads to a devastating flood that causes crop failure. Scanty rainfall or short summer monsoon may cause extensive drought condition when no crop can be produced.

Question 22. Compare between Retreating S.W. Monsoon and North-East Monsoon.
Answer: Comparison between Retreating S.W. Monson & N.E. Monsoon:

India – Climate Of India 5 Marks Questions And Answers:

Question 1. Name and describe the rainfall regions of India.
Answer: There are five rainfall zones in India. They are the following:

(1) Excessive rainfall regions: Regions experiencing 320 cm of rainfall or more, include the parts of Assam, Meghalaya, Arunachal Pradesh and mountainous tracts of the Western Ghat.

(2) Heavy rainfall regions: Regions experiencing 200 to 320 cm rainfall, include parts of Maharashtra (Western Ghat), Assam, Meghalaya, Arunachal Pradesh, Nagaland, Manipur, Tripura and West Bengal.

(3) Moderate rainfall region: Regions with 100 to 200 cm of rainfall, including major parts of West Bengal, Bihar, Orissa, Madhya Pradesh, Andhra Pradesh and some parts of other states.
(4) Scanty rainfall regions: Regions having 50 to 100 cm of rainfall, include the parts of Maharashtra, Gujarat, Karnataka, Tamil Nadu, Andhra Pradesh, ay Punjab, Haryana and Western Uttar Pradesh.
(5) Desert and semi-desert regions: Regions having below 50 cm of rainfall, include desert and semi-desert parts of Rajasthan, Gujarat and adjoining regions.

Geography Class 10 Solutions WBBSE

Question 2. Describe the seasons of India.
Answer: Seasons of India: The Meteorological Department of the Government of India has divided the climate of India into four seasons on the basis of the arrival and departure of the monsoons, total annual rainfall, temperature, air pressure, etc.

1. Winter Season or Cold Weather Season(December to February): The winter season lasts for 3 months in India. Sunrays fall vertically on the tropics in the southern hemisphere, while in the northern hemisphere they fall obliquely. The oblique rays, therefore, cause the temperature to decrease over the whole of India. The cool and dry northeast monsoon winds blow over India to the equatorial low-pressure region to the south.

The temperature during the winter season: Compared to south India the temperature over north India is low in winter. The average temperature is between 10°C to 15°C over north India. In winter the mountain regions of north India have temperatures below the freezing point. In 1991, during winter the Lahul, Spiti region of Himachal Pradesh experience the lowest temperatures, below —40°C which continued for some days. In the Kashmir and Kumaon Himalayas too the temperatures fell far below the freezing point at that time. In 1995 the Ladakh region of Kashmir experienced temperatures below —50°C in January. in winter the isotherm line shows temperatures to be rising gradually from the North to the South until it is 25°C over Tamil Nadu.

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Rainfall during the winter season: The northeast monsoon winds are dry, so there is little rainfall in winter in India. But these winds pick up moisture while blowing over the Bay of Bengal and give rainfall to the Coromandal Coast of Tamil Nadu. Sometimes from the Mediterranean regions, cyclonic disturbances enter India from the northwest and give some rainfall to this north-western area, the Ganga Plains and snowfall in the Himalayan region. These depressions coming from the west disrupt the quiet weather in winter and are, therefore, called Western Disturbances.

 

2. Summer Season or Hot Weather Season(March to May): This season lasts for 3months. By the end of March, the temperature starts rising in India. The vertical rays of the sun nearly reach the Tropic of Cancer after passing through the middle of India by the month of May. Thus the temperatures shoot up over the mainland of India.

The temperature during the summer season: In May the temperatures rise from 38° to. 40°C over Madhya Pradesh and Gujarat. Over the desert regions of Rajasthan, it is nearly 48°C. This results in the formation of an intense low-pressure cell over the desert region. The nearness of the ocean in South India does not allow the temperature to increase very high. The high temperature causes a hot, dry wind to blow during the daytime over northwestern India. Over the Indo-Ganga Plain, it is called the Loo and in Rajasthan, it is called Andhi.

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Rainfall during the summer season: In summer rainfall is not high. Various parts of the country have local low pressure which brings in strong together with rainfall, thunder, and lighting. Such storms are called Kal Baisakhi in west Bengal , ‘Bordoichila in Assam, and Mango Showers in South India

3. Rainy Season or South-West Monsoon Season (June to September): The rainy season lasts for 4 months in India. The strong low-pressure cell formed over the desert region of Rajasthan in summer attracts moist winds from the far-off Indian Ocean. As these winds come from the southwest, they are called the South-West Monsoon winds. By the first week of June, this monsoon wind enters India and the whole of India comes under its influence by the 15th of July. The arrival of the southwest monsoon is heralded by overcast skies and the sudden thunder and lightning that accompanies the heavy rainfall. As the monsoon suddenly begins with all this light and sound, it is called the Burst of Monsoon.

The south-west monsoon winds are divided into two branches:
(1)Arabian Sea Branch and
(2)Bay of Bengal Branch.

(1)Arabian Sea Branch: The Arabian Sea Branch of the monsoons is first obstructed by the Western Ghats; they are forced to rise and give heavy rainfall. Becoming lighter they cross the mountain and blow down the slopes to the east to the interior of the plateau giving little rainfall. The eastern slopes of the Western Ghats, therefore, form the rainshadow area, receiving little rainfall. Some of the Arabian Sea branches of the monsoon move further northwards blowing over Gujarat and part of Rajasthan.
(2) Bay of Bengal Branch: The Eastern Himalayas and the Purbanchal Mountains obstruct the path of the Bay of Bengal branch of the monsoons as the winds arrive. Thus, on the southern slopes of the Khasi Hills of Meghalaya, Mausinram near Cherrapunji receives the highest rainfall in the world, 1250 cm. Then this branch of monsoon divides into 2 branches, one moving to the Brahmaputra Valley in the east and the other moving to Bihar and U.P. in the west.

Rainfall during southwest monsoon season: To the total annual rainfall in India nearly 75% to 80% of the rainfall occurs in the rainy season. The maximum rainfall occurs in the west coastal plain and north-eastern mountainous region of India where the rainfall is more than 200 cm. Except for the desert region, northwestern India receives 60 to 200 cm of rainfall.

The temperature during southwest monsoon season: The sky is mainly overcast during this season and rainfall occurs heavily. So, the temperature is low over the entire India. In North India, it varies between 20° to 25°C and in South India, it varies between 20° to
30°C.

4. Autumn Season or Retreating South-West Monsoon Season (October to November): It lasts for 2 months. In the apparent annual movement of the sun, the vertical rays of the sun now move from the Equator to the Tropic of Capricorn. The rainfall in the previous season lowers the temperature over the Indian mainland. So the low-pressure cell disappears and the southwest monsoon wind retreats from India. With the rains departing the skies become clear.

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Temperature and rainfall during the autumn season: Clear skies cause temperatures to rise for some time. But the gradual arrival of the northeast monsoon winds from cold Central Asia lowers the temperature to a certain extent. The coastal regions in India experience cyclonic rainfall. This is also known as the October rains. These rains are not heavy but cause great damage to life and property.

Question 3. Discuss the influence of the South-West monsoon on India.
Answer: The influence of the South-West monsoon on India may be discussed as follows:

1. For the tremendous influence of the South-West Monsoon, India is often called ‘the land of monsoon’. The whole of the Indian climate remains within the grip of mon- soon throughout the year. It rules over the summer and parts of autumn. The North-East monsoon comes in the winter climate.

2. The South-West monsoon is responsible for the great amount of rainfall that occurred in India. From the early part of June, the South-West monsoon begins to invade the land of India. It brings moisture from the Southern Seas (the Indian Ocean, the Arabian Sea, and the Bay of Bengal). It gives rain all over the country; the distribution of rainfall, however, is not even all over; it is uneven according to the layout of the mountains and relief features. North-east India receives maximum rainfall (over 300 cm); the western part of the Western Ghats receives heavy rainfall (250 to 350 cm); the other parts of India receive a sufficient amount of rainfall (average between 130 and 175 cm); the north-western parts and western parts get low rainfall; and the lowest rainfall occurs in Rajasthan.

3. The fate of Indian agriculture largely depends on the southwest monsoon. It influences the cultivation of various types of crops for which India is famous. A variety of crops are grown for the uneven distribution of rainfall caused by the South-West
monsoon.

4. It is to the influence of the South-West monsoon, India has become a resourceful agriculturist country.

5. The whole of the Indian economy is largely influenced by the South-West. monsoon. Sometimes, monsoon failures cause great disasters. Again, the success of the monsoon brings smiles to the poverty-stricken Indian farmers.

6. The country’s major agro-based industries (cotton textiles, jute textiles, tea) also depend on the South-West monsoon and the success of agriculture. Thus, we see that the influence of south-west monsoon on India is of great import- ance. In fact, the South-West monsoon is one of the great resources of India.

Question 4. What are the controlling factors of the Indian climate? Discuss in brief.
Answer: The controlling factors of Indian climate are:

1. Latitudinal location: Tropic of Cancer passes through the middle of the country. As a result, the southern half of the country falls in the Tropical zone while the northern half is in the warm temperate zone. But the country, on the whole, experiences a tropical temperate climate.

2. Monsoon winds: The word is derived from the Arabic word mausim, meaning season. Actually, monsoon winds are the enlarged form of land breezes and sea breezes. The land breeze and sea breeze blow for six months from sea and the other six months from land masses. In the summer season of the Northern hemisphere low-pressure area is formed over the central hilly and mountainous region of Asia while a high-pressure area is formed in the southern hemisphere. The result is that winds blow from the South of the equator to the North and according to Ferrel’s law, they deflect towards the right. Thus the winds blow from a south-westerly direction. These are known as S.W. monsoon winds.

They divide into two branches: the Arabian Sea Branch and the Bay of Bengal Branch. They strike against the Western Ghat mountains giving
early and heavy rain to the coasts of Konkan and Malabar. The S.W. monsoon then loses its moisture and gives no rain or little rain to the Deccan trap (leeward side). Again, when it crosses the Bay of Bengal the winds become moisture-laden and join the Bay branch. It gives rain after striking the eastern Himalayas. Thus Andaman and Nicobar islands experience equatorial rainfall throughout the year and the western coast receives the first downpour of SW monsoon after striking the eastern Himalayas and giving rain to N.E. India and West Bengal. The monsoon currents move westward and give rainfall to the northern plain in the last week of June.

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In winter the dry north-east monsoon brings rainfall to the eastern coast (the Tamil Nadu coast) after taking moisture from the Bay of Bengal. During winter the low pressure of the Bay helps in the formation of the cyclonic storm that strikes the coast of Orissa, Andhra Pradesh, and Tamil Nadu.

3. Inter Tropical Convergence: In the winter the Indian climate is influenced by the western disturbances originating from the Mediterranean sea and characterised by snowfall or rainfall (its influence is seen sometimes upto the plains of West Bengal also). Kashmir, Punjab, and Western U.P. receive snowfall or rain during this time.

4. Mountains: Mountains play a significant role in influencing the Indian climate. The Himalayas on one side obstruct the cold winter winds from coming over to India, otherwise, the country would have been a cold desert like Tibet, and on the other side, checks the moisture-laden SW monsoon winds resulting in rainfall throughout the country. Again, the Aravalli range is situated parallel to the direction of NE and SW monsoon
winds making the region rainless.

5. El-Nino and La-Nina: El-Nino is a warm surface ocean current that appears off the coast of Peru in South America. It is a temporary replacement of the cold Peruvian current flowing along that coast. It happens to increase the temperature of tropical Pacific waters by about 10°C causing flood and drought in the tropical regions of the world. India lying in the Tropical region also experiences such flood or drought situations due to its effect. La-Nina or anti-El-Nino is the cooling of surface ocean water along the tropical west coast of South America. It causes heavier summer monsoons in southeast Asia. This benefits the Indian economy, which depends on monsoons for agriculture and industry.

Question 5. Give an account of the summer monsoon and winter monsoon in brief.
Answer: Monsoons are periodic seasonal winds. They develop because of differential heating as well as cooling of land and sea. They are divided into two wind systems the Summer Monsoon and the Winter Monsoon.

Summer Monsoons: In summer, the land gets heated more than the sea. Hence there develops a center of low pressure on the land. Over the adjoining sea, the air is comparatively cool, and a high pressure develops there. This causes the winds to blow from the sea to the land. It is the ‘Summer Monsoon’.

In May, June, and July, the plains of the Indian subcontinent are heated by the vertical rays of the sun. The intense heat develops a low pressure. During these months, over the Indian Ocean, a high-pressure area develops. So, the winds blow from the Indian Ocean northward and northwestward into Asia. As they blow from the sea to the land, they bring heavy rainfall in some parts of the Indian subcontinent. The summer monsoon winds blow south-west; so they are known as the ‘South-West
Summer Monsoon’.

Winter Monsoons: During the winter season, the conditions are just the reverse of those in summers. A high pressure develops over a big landmass stretching from Central Asia upto the northwest Indian plain. At the same time, a low-pressure zone develops in the Indian Ocean. As the winds blow from the land to the sea, they bring cold dry weather. They are incapable of producing rain.

When these winds blow overseas and pass over the adjoining land, they bring some rainfall. The Southern Coromandal Coast (Tamil Nadu) in India gets rain from winter monsoons. The winter monsoon winds blow northeast; so the monsoon is known as the ‘North-East Winter Monsoon’.

WBBSE Class 10 Geography Solutions

Question 6. How does monsoon result: in drought and flood? Explain.
Answer: Drought: Drought is a distress situation caused by the failure of rainfall when surface water is in short supply and groundwater loses its potentiality. A drought condition adversely affects the biotic life of the area. The rainfall may be insufficient and may not occur at the required time. Thus the quantum as well the time of rainfall both are important. However, drought is a relative phenomenon in the sense that the amount of moisture available is not as important as its effectiveness.

Droughts in India occur in the event of a weak southwest monsoon. A weak monsoon results in deficient rainfall and so droughts occur. Droughts also occur due to late arrival or early withdrawal of the monsoon. Prolonged breaks. in the monsoon during the rainy season also result in droughts. Although a drought may occur at any time and in any part of the country, most of the drought-prone areas are those having marginal rainfall and high variability of rainfall. i

Floods: A flood is a state of high water level along a river channel or on the sea coast that leads to inundation of land which is not submerged in normal circumstances. Flood is an attribute of the physical environment and this is an important component of the hydrological cycle of a drainage basin. As drought occurs due to the failure of rainfall, floods are the result of heavy rainfall. Thus droughts and floods are the extreme ends of the hydrological cycle. Flood is a natural phenomenon in response to heavy rainfall but it becomes a hazard when it inflicts loss to lives and properties of people.

Floods comprise another natural climate that India has to face almost every year. Floods are caused by excessive rainfall by the southwest monsoons, tropical cyclones in the pre and post-monsoon periods, silting of the river beds, changes in the river courses, and deforestation.

Class 10 Geography WBBSE Chapter 2 Atmosphere True Or False Type:

Question 1. Mistral is a warm local wind which blows over Rhone valley in France.
Answer: False

Question 2. Wind velocity is measured with the help of an Anemometer.
Answer: True

Question 3. The air pressure is measured with the help of Fortin’s Barometer.
Answer: True

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 4. The ozone layer is known as “Natural sun-screen”.
Answer: True

Question 5. In Mediterranean regions, rainfall generally occurs in summer.
Answer: False

School Geography Class 10 WBBSE

Question 6. Nitrogen occupies about 21% of the atmosphere by volume.
Answer: False

Question 7. Conduction is the process by which heat is transferred by contact.
Answer: True

Question 8. Vertical rays are cooler than slanting rays.
Answer: False

Question 9. The normal Lapse Rate is 0.6°C per 100 m.
Answer: True

Question 10. Mercury has a freezing point of —40°C.
Answer: True

Question 11. Alcohol has a freezing point of -130°C.
Answer: True

Question 12. A hygrometer measures the relative humidity.
Answer: True

Question 13. The lowest layer of the atmosphere is the stratosphere.
Answer: False

Question 14. Convectional rainfall mainly occurs in the equatorial region.
Answer: True

Question 15. Insolation is the incoming solar energy.
Answer: True

Question 16. There are seven heat zones.
Answer: False

Question 17. There are five pressure belts.
Answer: False

Question 18. An anemometer measures wind velocity.
Answer: True

Question 19. Windvane determines the direction of the wind.
Answer: True

School Geography Class 10 WBBSE

Question 20. Fohn is a local wind.
Answer: True

Question 21. Monsoon is a periodical wind.
Answer: True

Question 22. Trade winds are planetary winds.
Answer: True

Question 23. Orographic rainfall occurs at the windward side of the mountain.
Answer: True

Question 24. Brave westerlies flow in between 40-60 north latitudes.
Answer: False

Question 25. The humidity of air is measured by a hydrometer.
Answer: False

Question 26. Sixty-six per cent of the solar rays is responsible for the heating of the atmosphere.
Answer: True

Question 27. The wind velocity is so high and roaring at 40°S latitude that it is called horse latitude.
Answer: False

Question 28. The upper atmosphere is so thin that there is not enough air to breathe.
Answer: True

Geography Class 10 West Bengal Board Chapter 2 Atmosphere Fill In The Blanks Type:

Question 1. Oases are formed by ______ action of wind.
Answer: Deflation.

Question 2. _______ is formed by the mixing of dust and fog during winter in the industrial region.
Answer: Fog

Question 3. Tropical easterly Jet Stream forces ______ wind to blow over India.
Answer: Monsoon

Question 4. Temperature increases with the increase of altitude in the atmosphere is called _______.
Answer: Inversion of temperature.

School Geography Class 10 WBBSE

Question 5. In the Rainfall-Temperature graph of any place, if the temperature curve becomes downward sloping during the middle of the year then the station lies in ______ hemisphere.
Answer: Southern.

Question 6. In the southern hemisphere, an anti-cyclone moves _______.
Answer: Anti-clockwise.

Question 7. Fog is caused in the atmosphere due to ______ of water vapour.
Answer: Condensation.

Question 8. The relative humidity of the air is measured by ______.
Answer: Hygrometer.

Question 9. _______ rainfall occurs in the equatorial region in the afternoon.
Answer: Conventional.

Question 10. The rainshadow area is found on the _______ slope of the mountain.
Answer: Leeward.

Question 11. The relative humidity is expressed in _______.
Answer: Percentage.

Question 12. The sea breeze blows during ______.
Answer: Day.

Question 13. The range of temperature is maximum in the ______ region.
Answer: Desert.

Question 14. Rainfall is ______ on the leeward side.
Answer: Scanty.

Question 15. Convectional rainfall occurs in ______ region.
Answer: Equatorial.

Question 16. The line which connects the places with equal pressure of air is called ______.
Answer: lobar.

Question 17. The most abundant gas in the atmosphere is ______.
Answer: Nitrogen.

Question 18. The pressure of air at sea level is ______ millibar.
Answer: 1013.

Question 19. Two major constituent gases of air include nitrogen and ______.
Answer: Oxygen.

Question 20. ______ is a line joining places having an equal temperature.
Answer: Isotherm.

Question 21. _______ is a line joining places having equal pressure.
Answer: Isobar.

Question 22. _______ is a line joining places having equal rainfall.
Answer: Isohyet.

Question 23. ______ is the maximum rain-giving cloud.
Answer: Nimbus.

Question 24. _______ is a hot wind blowing over the rocks.
Answer: Chinook.

Question 25. ________ is a cold wind blowing over France.
Answer: Mistral.

Geography Class 10 West Bengal Board

Question 26. The climate of the place far off the ocean is of _______ type.
Answer: Continental.

Question 27. The expansion of the atmosphere is _______ km.
Answer: 10,000 km:

Question 28. Loo is a _______ wind.
Answer: Temporary.

Question 29. The lowermost layer of the atmosphere is called _______.
Answer: Troposphere.

Class 10 Geography WBBSE Chapter 2 Atmosphere Very Short Answer Type Questions:

Question 1. Where in the atmosphere over the earth’s surface ozone hole was first discovered?
Answer: Antarctica.

Question 2. Which type of rainfall is found in the Temperate zone?
Answer: Cyclonic rain.

Question 3. Which island of Sundarban was completely submerged due to global warming?
Answer: Lohachara, Needmore.

Question 4. In which layer of the atmosphere jet plane flies?
Answer: Stratosphere.

Question 5. What is the relative humidity of saturated air?
Answer: 100%.

Geography Class 10 West Bengal Board

Question 6. Name the instrument by which relative humidity is measured.
Answer: Relative humidity is measured by Hygrometer.

Question 7. Give a single term for each of the following:
1. The zone which separates the troposphere from the stratosphere.
2. The layer of the atmosphere where conditions are ideal for flying.
3. The layer of the atmosphere which reflects the radio waves back to the earth’s surface.
4. The vast expanse of air which envelopes the earth all around.
5. The atmosphere layer lies between the stratosphere and the ionosphere.
6. The uppermost layer of the atmosphere.

Answer:
1. Tropopause.
2. Stratosphere.
3. ionosphere.
4. Atmosphere.
5. Mesosphere.
6. Exosphere.

Question 8. Where is the coldest place on earth?
Answer: The pole of cold (78°S, 96°E) in Antarctica with an annual mean of — 72°F is the coldest place on earth.

Question 9. Where is the world’s desert place?
Answer: Calama, in the Atacama desert, Chile.

Question 10. What is isohyet?
Answer: Isohyet is an imaginary line joining places of equal amounts of rainfall. Isohyet is mainly used in the climatic map.

Question 11. Where is the foggiest place on earth?
Answer: The Grand Banks, Newfoundland, Canada where at sea-level fog persists for more than 120 days a year.

Question 12. What is the imaginary line joining places having equal temperatures called?
Answer: Isotherm.

Question 13. What is the warm, nutrient-poor water of Northern Peru called?
Answer: El Nino.

Question 14. Name the instrument used to measure air pressure.
Answer: Barometer.

Question 15. What do we call the winds that blow from one direction throughout the year?
Answer: Planetary winds.

Question 16. What is the warm dry wind blowing along the leeward slope of the Alps called?
Answer: Foehn.

Question 17. Name the rainfall that occurs in the presence of a mountain or plateau.
Answer: Orographic rainfall.

Question 18. What is the height of the atmosphere according to the latest discoveries?
Answer: 32,000 km.

Geography Class 10 Solutions WBBSE

Question 19. What are the major constituents of pure dry air?
Answer: Gases.

Question 20. Which gas is most essential for life?
Answer: Oxygen.

Question 21. Name the gas which is found in the lower part of the atmosphere.
Answer: Carbon dioxide.

Question 22. Which gas is mainly found in the upper part of the atmosphere?
Answer: Hydrogen.

Question 23. Which gas absorbs ultraviolet radiation from the sun?
Answer: Ozone.

Question 24. Name two major constituents of the atmosphere apart from the gases.
Answer: Water vapour and dust particles.

Question 25. Name the main layers of the atmosphere.
Answer: Troposphere, stratosphere, mesosphere, ionosphere and exosphere.

Question 26. Which atmospheric layer is most important for us?
Answer: Troposphere.

Question 27. What is the average height of the troposphere?
Answer: 16 km.

Question 28. What is the height of the troposphere at the equator and the poles respectively?
Answer: 18 km and 8 km respectively.

Geography Class 10 Solutions WBBSE

Question 29. Name the thin layer which separates the troposphere from the stratosphere.
Answer: Tropopause.

Question 30. How much is the normal lapse rate in the troposphere?
Answer: 1°C for 165 metres or 6.4°C for 1 km.

Question 31. Which layer of the atmosphere reflects radio waves?
Answer: the ionosphere.

Question 32. Why do jet planes prefer to fly higher than ordinary planes?
Answer: To avoid lumpy air pockets of the Troposphere.

Question 33. What is the unit of measuring ozone?
Answer: Dobson Unit (DU).

Question 34. Which gas is mainly responsible for ozone layer depletion?
Answer: Chlorofluorocarbon (CFC).

Question 35. Where is the ozone hole?
Answer: Over the Antarctica continent.

Question 36. What part of solar radiation is received by earth?
Answer: Two billionth part.

Question 37. Through which processes atmosphere is heated?
Answer: Radiation, condensation, convection and advection.

Question 38. What is the unit of measuring insolation?
Answer: Calorie.

Question 39. What is the standard sea-level pressure in millibars?
Answer: 1013.25 millibars.

Question 40. What is the rate of fall of atmospheric pressure with height?
Answer: 34 millibars per every 300 metres.

Geography Class 10 Solutions WBBSE

Question 41. Which unit of atmospheric pressure is used while drawing an isobaric map?
Answer: Millibar.

Question 42. Name the effect or force due to which winds are deflected from their path as a result of the earth’s rotation.
Answer: Coriolis effect.

Question 43. By which law is Coriolis force known?
Answer: Buys Ballot’s law or Ferrel’s law.

Question 44. Where do you find the maximum and minimum deflection of winds by the Coriolis effect?
Answer: At the poles and equator respectively.

Question 45. Name two permanent winds.
Answer: Trade winds and westerlies.

Question 46. Between which latitudes do westerlies blow?
Answer: 30°N and S latitudes.

Question 47. What is the direction of the flow of trade winds in the northern hemisphere?
Answer: From northeast to the southwest.

Question 48. Between which latitudes do westerlies blow?
Answer: From 30°—40° to 60°—-65° latitudes.

Question 49. Where do the Roaring Forties, Furious Fifties and Shrieking Sixties blow respectively?
Answer: At 40°, 50° and 60° South latitudes respectively.

Question 50. What is the literal meaning of Chinook?
Answer: Snow-eaters.

Question 51. Through which valley mistral wind blows?
Answer: Rhone valley.

Question 52. Name two broad types of cyclones.
Answer: Temperate and tropical cyclones.

Question 53. What are the two other names of temperature cyclones?
Answer: Depressions and western disturbances.

Geography Class 10 Solutions WBBSE

Question 54. Who propounded the polar front theory of the origin of temperate cyclones?
Answer: Vilham Bjerkens and his son Jacob Bjerkens.

Question 55. Where is the eye of a tropical cyclone located?
Answer: At its centre.

Question 56. What does ITCZ stand for?
Answer: Inter-tropical convergence zone.

Question 57. Give one technical term for each of the following:
1. An imaginary line drawn through places having equal atmospheric pressure reduced to sea level.
2. Air that moves horizontally along the earth’s surface.
3. Deflecting force due to rotation of the earth.
4. Winds blowing over the south and southeast Asia are characterized by a reversal in wind direction with a change in a season.
5. Winds blowing from the sub-tropical high-pressure belts towards the sub-polar low-pressure belts.
6. A warm dry wind, known as a snow-eater, blows on the eastern side of the Rocky Mountains.
7. A large body of air with uniform properties of temperature and humidity.
8. The contact line between air masses of different properties.
9. Azone of calmness in the vicinity of the equator on both sides.
10. An air mass originating over tropical oceans.

Answer:
1. Isobar,
2. Wind,
3. Coriolis force,
4. Monsoon winds,
5. The westerlies,
6. Chinook,
7. Air mass,
8. Front,
9. Doldrum,
10. Tropical Maritime.

Question 58. What is a ‘ Jet Stream’?
Answer: A jet stream is a high-altitude air movement consisting of very strong winds concentrated in a narrow belt.

Question 59. Give a single technical term for each of the following:
1. The process by which water is transformed from liquid to vapour or gas.
2. The amount of water vapour actually present in per unit volume of air.
3. The amount of water vapour actually present in per unit weight of air.
4. Ratio of the amount of water vapour actually present in the air at a particular temperature to the amount of water vapour required to saturate the same air at the same temperature.
5. The air that contains moisture to its full capacity.
6. The process of change of state from gaseous to liquid or solid forms of water.
7. The temperature at which condensation starts.
8. Falling of the frozen raindrops and refrozen melted snow on the earth’s surface.

Answer:
1. Evaporation,
2. Absolute humidity,
3. Specific humidity,
4. Relative humidity,
5. Saturated air,
6. Condensation,
7. Dew point,
8. Sleet.

Geography Class 10 Solutions WBBSE

Question 60. Name the factors controlling the rate of evaporation.
Answer:
1. Temperature,
2. Dryness of air,
3. Clouds,
4. Size of the water area,
5. Movement of air.

Question 61. Name three forms of humidity.
Answer:
1. Absolute humidity,
2. Specific humidity,
3. Relative humidity.

Question 62. What is the unit of measurement of relative humidity?
Answer: Present.

Question 63. Name various forms of precipitation.
Answer:
1. Snowfall,
2. Sleet,
3. Hail-fall,
4. Rainfall.

Question 64. Which type of rainfall generally occurs in the equatorial region?
Answer: Convectional rainfall.

Question 65. Which type of rainfall is associated with the following:
1. Convection currents,
2. Relief,
3. Convergence of cold and warm air masses?

Answer:
1. Convectional rainfall,
2. Orographic rainfall,
3. Cyclonic rainfall.

Question 66. Which part of South India receives orographic rainfall?
Answer: Western Ghats and West Coastal plains.

Question 67. What type of rainfall occurs in northwest India during winter?
Answer: Cyclonic rainfall.

Geography Class 10 Solutions WBBSE

Question 68. What climatic data are used for classifying climates?
Answer: Temperature and precipitation.

Question 69. Which type of climate is known for the minimum annual range of temperatures?
Answer: Equatorial climate.

Question 70. In which climate evaporation is higher than precipitation?
Answer: Desert climate.

Question 71. Which climate has rainfall in winter and practically no rainfall in summer?
Answer: Mediterranean climate.

Question 72. What is the significance of the 10°C summer isotherm?
Answer: It marks the southern boundary of the Tundra climate.

Question 73. Listed below are some important characteristics of a few climate types. Name the climatic types of which they refer to:
1. High temperature throughout the year, wet summers and dry winters.
2. Greatest daily ranges of temperature on the earth.
3. Reversal in wind direction with a change of season.
4. Constantly high temperatures and heavy precipitation throughout the year.
5. Warm and dry summer, mild winter, moderate rainfall mostly in winter.
6. Short summer temperature ranging between 10°C to 15°C, long and very cold winters, and low precipitation mostly in warmer months.
7. Severe winter, cool summer with temperature not rising above 10°C.

Answer:
1. Wet and dry (Savanna) climate,
2. Desert climate,
3. Monsoon climate,
4. Equatorial climate,
5. Mediterranean climate,
6. Boreal (Taiga) climate,
7. Tundra climate.

Geography Class 10 Solutions WBBSE

Question 74. Which type of cloud produces the maximum rainfall?
Answer: Cumulonimbus (Cu-Ni) cloud is a type of cloud which produces maximum rainfall.

Question 75. How many pressure belts are there on the surface of the earth?
Answer: There are seven pressure belts on the surface of the earth.

Question 76. Give an example of periodic wind.
Answer: Monsoon is an example of periodic wind.

Question 77. What is Terrestrial radiation?
Answer: The sun’s energy absorbed by the Earth’s surface when radiated out into space is called terrestrial radiation.

Question 78. What is the weight of the atmosphere?
Answer: 9046 thousand crore tones.

Question 79. Name two scientists who divided the atmosphere into two parts — Homosphere and Heterosphere.
Answer: Jastrio and Nicholas.

Question 80. Who invented the term ‘Tropopause’?
Answer: Sir Napier Shaw.

Question 81. In which layer of the atmosphere does aeroplanes fly?
Answer: Stratosphere layer.

Question 82. What is insolation?
Answer: Radiant energy from the sun that strikes the earth is called Insolation.

Question 83. What is the barometric slope or pressure gradient?
Answer: The difference of pressure between any two places is called pressure gradient or barometric slope.

Question 84. What do you mean by ITCZ?
Answer: The meeting zone of the trade winds and the equatorial westerlies is called the Inter Tropical Convergence Zone (ITCZ),

Question 85. What is the unit of measurement of clouds?
Answer: Okta or Tenths.

Question 86. Name the scale for ascertaining the speed of the wind.
Answer: Beaufort scale.

WBBSE Class 10 Geography Solutions

Question 87. What is heat balance?
Answer: The amount of energy received and lost by the atmosphere is called the heat balance.

Question 88. What is insolation?
Answer: The incoming solar radiation is called Insolation.

Question 89. What do you mean by daily range of temperature?
Answer: The daily range of temperature is the difference between the highest and the lowest temperature over a period of 24 hours.

Question 90. What do you mean by daily mean temperature?
Answer: The daily mean temperature is the mean of the maximum and the minimum temperatures of 24 hours.

Question 91. What do you mean by a diurnal range of temperature?
Answer: Diurnal range of temperature is the difference between the maximum and the minimum temperatures of a day.

Question 92. What do you mean by mean monthly temperature?
Answer: Mean monthly temperature is the average of the mean temperatures of all days in a month.

Question 93. What do you mean by an annual range of temperature?
Answer: Annual range of temperature is the difference between the mean temperature of the hottest month and that of the coldest month in a year.

Question 94. What is a pressure gradient?
Answer: The rate of fall of pressure per unit of horizontal distance.

Question 95. What is atmospheric pressure?
Answer: The force exerted by the vertical column of air per unit of area is called atmospheric pressure.

Question 96. Give an example of periodic wind.
Answer: A monsoon wind is a periodic wind.

Question 97. Name the instrument by which air temperature is measured.
Answer: Six’s thermometer.

School Geography Class 10 WBBSE Chapter 2 Atmosphere 2 Marks Questions And Answers:

Question 1. What is Doldrum?
Answer:
Doldrum: The equatorial region (the latitudes between 5°N and 5°S) is generally known as doldrum or equatorial calm. Over the equatorial region due to the continuous ascent of warm-moist air, there is no horizontal flow of air. So it is known as a doldrum.

Question 2. What is “inversion of temperature”?
Answer: Generally there is a decrease in temperature as we ascend upward above sea level, but sometimes temperature increases as we ascend upward. This is known as “Inversion of temperature”.

WBBSE Class 10 Geography Solutions

Question 3. What is ‘Chinook’?
Answer:
Chinook: Chinook is a warm, dry, gusty wind blowing down the Rocky mountains by the eastern slopes into the western prairies.

Question 4. Mention two characteristic features of Jet Streams.
Answer:
Characteristic features of Jet Streams:

1. It blows from west to east.
2. Length of the jet stream can be a few thousand kilometres.

Question 5. Discuss the relationship between Jet Stream & Monsoon.
Answer:
Relation between Jet Stream and Monsoon wind: The westerly jet stream causes high pressure on the Indian subcontinent in winter. Hence the monsoon winds start retreating. During the summer, the Tibet plateau gets excessively heated and drives the sub-tropical westerly jet stream north of the Himalayas.

The tropical easterly jet stream blows through the centre of the Indian subcontinent, causing low-pressure conditions. This gradually attracts the monsoon winds. The onset of the monsoons depends on the shifting of the sub-tropical jet stream towards the north.

As fast as this westerly jet moves northwards, the Tropical easterly jet sets in, and the monsoon winds are attracted. The sudden shift of the westerly jet stream northwards may cause a huge ‘Monsoon burst’.

Question 6. What do you mean by saturation & due point?
Answer: Saturation and Dew point: Air is said to be saturated when it contains water vapour in its full capacity. The temperature at which the air is saturated and below which condensation (the transformation of water vapour into water or ice) begins, is called the dew point.

Question 7. What is Meteorology?
Answer: Meteorology is the study of the atmosphere, and as the movements and composition of the atmosphere determine weather patterns, meteorology is the study of weather.

Question 8. If the temperature at sea level is 25°C, under average conditions, what would the air temperature be at a height of 2km?
Answer: The temperature decreases with the height at the rate of 1°C per 165 m. Therefore, for a height of 2 km or 2000 m the decrease in temperature \(\frac{2000}{165}\)= is 12°C nearly.

Therefore the temperature at the height of 2 km will be = 25°C— 12°C = 13°C.

Question 9. What is meant by the horizontal distribution of temperature?
Answer: Temperature varies from latitude to latitude. The horizontal distribution of temperature means the distribution of temperature according to latitude. It is shown by isotherms. In this distribution, the effect of altitude is eliminated so that the temperatures are reduced to sea level.

WBBSE Class 10 Geography Solutions

Question 10. Explain when minimum temperature occurs.
Answer:
The daily minimum temperature: The lowest temperature of the day is called the daily minimum temperature. The minimum temperature is not found at midnight. It is found at midnight. It is found at about 4 a.m. in the morning when the earth becomes cold due to rapid radiation. So the lowest temperature is found in the early hours of the morning.

Question 11. Explain the mean daily temperature of a place.
Answer:
Mean daily temperature: The average of the maximum temperature and minimum temperature recorded during a day is known as the mean daily temperature.

\(\text { Mean daily temperature }=\frac{\text { Max. temperature }+\text { Min. temperature }}{2}\)

For example, if a place has a maximum temperature of 42°C and minimum temperature of 28°C for a particular day, the mean daily temperature \(\frac{42^{\circ} \mathrm{C}+28^{\circ} \mathrm{C}}{2}\)= 35°C.

Question 12. Why are isotherms generally parallel to the parallels of latitude?
Answer: The isotherms generally trend east to west roughly parallel to the lines of latitudes. It is observed that the length of the day and the angle of the sun- rays are equal on all parts of the same parallel. All places on a parallel receive the same amount of insolation and have equal temperatures.

Therefore, the isotherms joining the places of equal temperature run roughly parallel to the lines of latitude. Thus due to the similarity between the distribution of insolation and latitude, isotherms follow parallels of latitude.

Question 13. Name the two factors which control the amount of insolation.
Answer:
The two major factors controlling the amount of insolation received on the earth’s surface are:

1. Intensity of insolation or the angle of incidence of sun rays.
2. The duration of solar radiation or length of the day.

All the places on the same parallel receive the same amount of insolation because the length of the day and the angle of the sun’s rays are equal on all parts of the same parallel.

Question 14. What is the relationship between heating, temperature and pressure?
Answer: There is a direct relation between heating, the temperature of air and atmospheric pressure. The chain of events follows from heating through temperature to pressure.

The land is heated through insolation. The air close to the surface is heated through conduction. Heating causes the expansion of air. It results in a decrease in convection. This leads to the development of low pressure as in the equatorial region.

Question 15. Why can clouds in tropical thunderstorms reach much greater heights than clouds in temperate areas?
Answer: The troposphere is 16-18 km high near the equator but only 10-11 km in the mid-latitudes. So clouds can rise higher in tropical areas.

WBBSE Class 10 Geography Solutions

Question 16. How is dew formed? How does it differ from fog formation?
Answer: When a layer of calm humid air immediately in contact with the ground is cooled, water may be formed directly on the cooler objects. This is dew. It is a contact process and no falling of water from the air is involved as in a fog.

Question 17. What is meant by the hydrological cycle?
Answer: By hydrological cycle we mean the movement of moisture from the ocean surfaces (or any other water surface) to the land where it is precipitated, and its ultimate return by evaporation and run-off to the sea.

Question 18. What do you understand by horse latitudes?
Answer:
Horse Latitudes: In the middle ages sailing ships carried a large number of horses and while crossing the subtropical belt of calm in the northern hemisphere they were stranded due to no horizontal movement of winds at these belts.

To reduce the load of the ships so that with little wind they could move, many horses were thrown overboard. In the northern hemisphere, the region between 30° to 35° N latitudes are, therefore, known as horse latitudes.

Question 19. What is ozone layer depletion?
Answer: CFC, CH_4,H₂o and other pollutants escape into the stratosphere and cause destruction of o₃ there. This is known as ozone layer depletion.

Question 20. What is the weather like?
Answer: The total sum of atmospheric conditions of a particular place at a given time is known as weather. It refers to a very short period of time.

Question 21. What is climate?
Answer: Climate is the atmospheric conditions of a very large area over a long period of time. It generally refers to those over 35 years.

Question 22. What do you understand by heat budget?
Answer: The amount of energy received and lost by the atmosphere is called the heat budget.

Question 23. Mention two effects of ozone layer depletion.
Answer: Two major effects of ozone layer depletion are:
1. The incidence of skin cancer and cataracts increases.
2. Diminishes the immune system.

WBBSE Class 10 Geography Solutions

Question 24. What is an ozone hole?
Answer: The decline in ozone layer thickness is termed as an ozone hole.

Question 25. Why is the stratosphere considered ideal for flying jet aircraft?
Answer: The stratosphere has no water vapour and dust particles. Air turbulence and clouds are absent and due to the absence of weather disturbances, this layer is considered ideal for flying jet aircraft.

Question 26. Write two differences between the normal lapse rate and inversion of temperature.
Answer:

Normal lapse rate	Inversion of temperature
(1)The decrease in temperature with increasing height is called the lapse rate.	(1)The increase in temperature with increasing height is called inversion of temperature.
(2)The lapse rate is higher in tropical areas than in polar areas.	(2)Inversion of temperature is a common phenomenon in mountain regions.

Question 27. Differentiate between Anabatic wind and Katabatic wind.
Answer:

AnabaticWind	Katabatic Wind
(1) It is a valley wind.	(1) It is a mountain wind.
(2) It blows from the valley’s bottom to the hillside slopes during the day.	(2) It is a downhill wind, usually cold, blowing into the valley at night.

Question 28. Why are the westerlies also called Anti-trade?
Answer: Westerlies are called Anti-trade also because their direction is opposite to that of the trade wind.

Question 29. What is a warm front?
Answer: A warm front is formed when a warm air mass is moving faster than the cold air so that warm air starts entering the air formerly occupied by the cold air.

Question 30. What is a cold front?
Answer: A cold front is formed when a cold air mass is moving faster and it starts replacing the warm air mass by invading in the area formerly occupied by warm air.

WBBSE Class 10 Geography Solutions

Question 31. What do you mean by precipitation?
Answer: Precipitation means ‘throwing down of moisture’ from the atmosphere. It is the collective name given to different forms of moisture falling on the earth from the condensation of water vapour in the atmosphere, such as:

1. Rainfall,
2. Snowfall,
3. Hail,
4. Sleet,
5. Dew and
6. Mist.

Question 32. What is Chinook?
Answer: Chinook is a type of local wind which is warm and dry and blows along the Eastern slopes of the Rockies into the Plains of Prairie. “Chinook” means snow eater.

Question 33. Why are cloudy nights warm?
Answer: Cloudy nights have more environmental humidity than clear-sky nights. Therefore, cloudy nights are warm.

Question 34. What are isobars and isotherms?
Answer:
Isotherms: isotherms are imaginary lines drawn on maps joining places having the same average temperature (reduced to sea level).

Isobar: An isobar is an imaginary line drawn on a map (or a weather chart) joining all areas having equal atmospheric pressure (reduced to sea level).

Question 35. What is relative humidity?
Answer:
Relative humidity: Relative humidity is the ratio between the actual amount of water vapour present in the air at a temperature and the maximum amount of water vapour which the same volume of air can hold at that temperature. This is expressed as a percentage.

Question 36. Write a note on Exosphere.
Answer: The exosphere is the outermost layer of the atmosphere which merges with the interplanetary medium, although there is no definite boundary with the ionosphere. It starts at a height of about 600 km. The composition of ratified gases mainly consists of a small amount of atomic oxygen up to 600 km and an equal proportion of hydrogen and helium with hydrogen predominating above 2400 km.

WBBSE Class 10 Geography Solutions

Question 37. What are the unique features of the ionosphere?
Answer: Air particles of the ionosphere are electrically charged by the sun’s radiation and congregate in four main layers : D, E, F, & F, which can mainly reflect radiowaves.

Aurora is caused by charged particles deflected by the earth’s magnetic field towards the poles (which occur between 65-965 km above the surface of the earth). The meteors from outer space burn up in this layer as they meet increased air resistance.

Question 38. What is the atmosphere?
Answer: The atmosphere is the gaseous blanket that encircles the earth.

Question 39. How many pressure belts are there on the surface of the earth?
Answer: There are seven pressure belts over the earth’s surface. Four of them are high-pressure belts and three are low.

Question 40. What is Fohn?
Answer: A hot dry wind blows over the northern slopes of the Alps and Rhine valley. The warm wind helps in snow melting & gives rise ‘to pasture in Rhine valley. This local wind is Fohn.

Question 41. What is the normal lapse rate?
Answer: Under normal conditions, temperature decreases with increasing height at the rate of 0-6°C per 100 metres, it is known as the normal lapse rate.

Question 42. What is ‘Doldrum?
Answer: A region calm on the equatorial belt (5° N & S) which has no horizontal movement of air, is called ‘Doldrum’.

Question 43. What is Heterosphere?
Answer: In the layer above the Homosphere, the percentage of gases varies and shows heterogeneous character and for this reason, the upper layer of the atmosphere is known as Heterosphere.

Question 44. What is Ferrel’s law?
Answer: Winds do not blow in a straight line. They change their direction while blowing. This is due to the rotational movement of the earth. In the northern hemisphere they deflect to the right while in the southern hemisphere, they deflect to left. This rule is known as Ferrel’s law. It is also applicable to an ocean current.

Question 45. What are planetary winds?
Answer: Planetary winds are permanent winds which originate due to the rotational movement of the earth. Example: Trade winds.

WBBSE Class 10 Geography Chapter 2 Atmosphere Short Notes:

Question 1. Ozone Depletion.
Answer:
Ozone Depletion: The extensive use of man-made chemicals called CFCs (Chlorofluorocarbons) has been confirmed to be the cause of the Antarctic ozone hole. CFC gases are used in refrigerators, aircraft and air-conditioners. CFC compounds escape into the atmosphere and finally break down in the stratosphere. They produce chlorine atoms which destroy the ozone layer. This phenomenon is termed as ozone depletion.

Question 2. Sea Breeze.
Answer:
Sea Breeze: During the daytime, the land gets rapidly heated up than the sea. The warm air rises to form a low pressure locally on land. The sea being cooler develops a high pressure. So a cool sea breeze blows from sea to land. Thus the winds complete a convection cycle.

Effects:
1. It brings cool and fresh air from the sea.
2. Sea breeze moderates the temperature of the coastal areas resulting in an equable or maritime climate.
3. Its influence does not exceed 20 miles from the coast.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 3. Land Breeze.
Answer:
Land Breeze: During the night the land becomes cooler than the sea. The cold and heavy air produces a local high pressure on land. The sea remains comparatively warmer with low pressure. Therefore, a land breeze blows from land to sea.

These are effective under a calm, cloudless sky.
1. The fishermen take advantage of the outgoing land breeze and sail out in the morning. They return with the incoming sea breeze in the evening.
2. The return current of warm air from the sea has a moderating effect on the temperature.

Question 4. Isobars.
Answer:
Isobars: Isobar is a combination of two words (Iso = equal, Bar = Pressure), So isobars are lines of equal pressure.

Isobar is an imaginary line joining places of equal pressure reduced to sea level. Pressure is reduced to sea level to eliminate the effects of altitude. Isobars, thus, show the distribution of pressure as if the whole earth were a level plain.

Main Characteristics:
1. isobars generally run in an east-west direction.
2. In the southern hemisphere these closely follow the lines of latitudes.
3. These are more regular in oceans than on land.
4. Isobars are used to show the distribution of pressure on climatic maps.

Question 5. Buys Ballot’s law.
Answer: This law clearly indicates the relation between the wind & pressure. Buy Ballot’s law states that — Stand with your back to the wind in the northern hemisphere, the low pressure will be towards your left and the high towards your right and the reverse applies in the southern hemisphere.

Question 6. Ferrel’s law.
Answer: Based on the Coriolis force of the earth and the deflection of winds Ferrel has propounded his law which is popularly known as Ferrel’s law. Ferrel’s law states that — the body, including a current of air moving in any direction over the earth, is deflected due to the earth’s rotation to the right in the northern hemisphere and to the left in the southern hemisphere.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 7. Horse latitude.
Answer: In the middle ages sailing ships carried a large number of horses and while crossing the sub-tropical belt of calm in the Northern hemisphere they often got stranded due to horizontal movements of the winds in this belt. To reduce the load of the ships, many horses were thrown overboard in the Northern hemisphere so it is known as Horse latitudes.

Question 8. Ozone layer.
Answer: The ozone layer of the atmosphere is stretched over a distance of 10-35 kilometres from the ground. The presence of the ozone layer in the lower stratosphere protects the earth from the harmful effects of the ultraviolet rays of the sun. But it is said that recently this ozone layer has been depleted in some parts of the world.

Major pollutants for ozone depletion are chlorofluorocarbons, nitrogen oxides and hydrocarbons. CFC or chlorofluorocarbons is the main threat to the ozone layer which is used in refrigerators, air conditioners, cleaning solvents and aerosol propellants. If the ozone layer is depleted, the whole creation of the earth would fall in danger and life would be at stake.

Question 9. Relative humidity.
Answer: Relative humidity is the ratio between the actual amount of water vapour present in the air at a temperature and the maximum amount of water vapour which the same volume of air can hold at that temperature. This is expressed as a percentage.

Example: The air at 15°C temperature has 16 g of water vapour per cubic centimetre but actually the air at the same amount of temperature (i.e., 15°C) can hold 20 g of water vapour per cubic centimetre.
Relative humidity = 16/20 x 100 = 80%.

Question 10. Smog.
Answer: The term smog was coined from the two words ‘Smoke’ and ‘Fog’. Smog is, therefore, a fog which is heavily laden with smoke. It is commonly found in industrial and densely populated urban areas.

Question 11. Local Wind.
Answer: Local winds blow over a limited area and are caused by local pressure conditions and relief features.

They may be of several types:
1. In high mountainous regions, due to the rapid fall of temperature at night, cold and dense air may slide down the mountain slope to occupy the valley bottom as Katabatic winds to cause an inversion of temperature. The Mistral of Rhone valley in Southern France and Bora in Yugoslavia are examples of Katabatic winds.

2. When winds are forced to descend on the leeward side of a mountain barrier, the air becomes hot and dry, and such winds are known as Descending or Compression winds. The Chinook in the Rocky Mountains and Fohn in the Alps are examples of this type.

3. Desert winds like Harmattan of West Africa and Sirocco of the Mediterranean basin are hot and dry winds which blow from deserts.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 12. Troposphere.
Answer: This is the lowest layer of the atmosphere. It is up to a height of 16 km on the equator and at the poles, the height is 8 km. The main feature of this layer is that temperature decreases in relation to height (for every 100-metre height the decrease in temperature is 0.6°C). 75% of all the water vapour, cloud, and dust particles are found in this layer. That is why this layer is called the ‘weather-making layer’.

Question 13. Albedo.
Answer: The ratio of total solar radiation falling upon a surface to the amount reflected from it expressed as a decimal to percentage is known as Albedo. A global average of about 40% of the incoming solar energy is reflected back into space. The reflected power of the earth is known as the Earth’s Albedo.

Question 14. Nor’wester.
Answer: These are violent storm winds. These are called so because they come from the North-West. These Nor’westers are known as Kal Baishakhi in West Bengal. They are called Kal Baishakhi which means ‘calamity of the month of Baishakhi’ because they cause much destruction in West Bengal and they occur is the month of Baishakh according to the Bengali calendar. The convergence of dry North-Western wind and moist Southern wind causes thunderstorms.

Question 15. Homosphere.
Answer: The proportion of gases varies greatly with height. Up to the height of nearly 100 km the composition and proportion of different gases in the atmosphere remains constant. This layer is known as Homosphere.

Question 16. Constituents of air.
Answer: The atmosphere is mainly composed of three elements. They are gases, water vapour and dust particles.

1. Gases: Of the various gases, Nitrogen (78.03%) and Oxygen (20.99%) are the most important ones, other gases are Argon (0.9%) and Carbon dioxide, Helium, Neon, Krypton, Hydrogen, Xenon, etc. (together 0.2%).

2. Water vapour: The amount of water vapour varies from time to time and from place to place. The percentage of water vapour decreases from the equator to the poles and the maximum amount is found between latitudes 10° and 30°.

3. Dust particles: These are mainly found in the lower atmosphere.

Question 17. ionosphere.
Answer: This is also known as Thermosphere. It is a zone of ion gas, electrons and atoms. The temperature increases very rapidly. The air in this layer contains electric charges and this reflects radio waves so that radio communication becomes possible.

It also absorbs the deadly ultraviolet rays of the sun. Thus, it is beneficial to human beings and other living creatures. The northern lights or Aurora Borealis and southern lights or Aurora Australis occur in this zone.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 18. Stratosphere.
Answer: This layer lies above the troposphere. Its average height is about 60 km. It is free from clouds, water vapour and dust particles. To avoid atmospheric disturbances, jet planes find their safe movement through this layer. The upper limit of this layer is known as Stratopause. o

Question 19. Normal Lapse Rate.
Answer: There is a decrease of temperature with the rise of altitude, which is known as the Normal Lapse Rate. We know that temperature decreases by 1°C at every 165 m of altitude. But this rate is not always the same at all places.

Question 20. Inversion of temperature.
Answer: Generally. there is a decrease in temperature as we ascend upward above sea level, but sometimes temperature increases as we ascend upward. This is known as “Inversion of temperature” or “Lapse rate of temperature”. The causes for the inversion are:

1. When in the calm and cloudless sky in the mid-latitude area, the radiation is swift or when a warm air current flows on a cold surface area of the earth.
2. On the upper slope of the mountain when radiation is rapid and the cold wind resembles the cold water or blows in a valley due to gravitation.

Question 21. Convectional rainfall.
Answer: When the land is intensely heated, the hot and moist air rises up vertically as convection currents. As the air rises up, it expands and cools and condensation takes place, resulting in the formation of cumulus clouds. The result is that torrential rainfall occurs. This type of rain occurs in the equatorial region.

Question 22. Roaring Forties. Convectional rainfall
Answer: In the southern hemisphere landmasses are less than that in the Northern hemisphere. The westerlies blowing near 40° latitude in the Southern hemisphere are not obstructed by the landmass. Hence, they blow with great velocity and make a roaring sound. Thus in 40° south latitude, the westerlies are known as Roaring Forties.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 23. Orographic Rainfall.
Answer: This is also known as Relief rain. When the vapour-laden winds come in contact with a high mountain, they move upward and are cooled, resulting in rain. This is known as Relief or Orographic rain. In monsoonal lands, this occurs in the summer season. There is no fixed time for this type of rainfall.

Question 24. Isotherm.
Answer: Temperature decreases at the rate of 1°F for every 300 ft ascent above sea level. Thus, the temperature of every place is not the same. Thus, the line joining the places of same temperature is known as an ‘Isotherm’.

Question 25. Atmosphere.
Answer: The atmosphere is the layer of air surrounding the earth. It is held to the earth by gravitational force. It extends to a height of 300 km. It is composed of various gases (Oxygen, Nitrogen, etc.). At sea level, the air is densest and becomes thinner according to ascent.

Question 26. Planetary winds.
Answer: These are permanent winds blowing from high-pressure areas to low-pressure areas.

There are three kinds of winds:
1. Easterlies or Trade winds,
2. Westerlies or Anti-trade winds and
3. Polar winds.

Question 27. Cyclonic rain.
Answer: When the warm moist air current and cold air current approach each other from opposite directions, the warm current being lighter go up and the cold air current blows below along the line of the frontal zone. In the process of ascent, the pressure decreases and the air expands, cools and condensation takes place. Thus, heavy clouds are formed and rain falls. It is associated with cyclones and is known as cyclonic rain; it mainly occurs in the temperate zone.

Question 28. Doldrums.
Answer: All along the equator and between 5° North and 5° South of the equator, allow pressure belt exists.

WBBSE Class 10 Geography Chapter 2 Question Answer

This is due to:
1. The vertical rays of the sun throughout, intense heat is caused. The hot air rises upwards as convection currents expand,
2. Presence of a large amount of water vapour makes the air lighter and,
3. Rotational force of the earth throws the air from the surface to make the pressure light. The movement of air is not horizontal but vertical, so these ascending air are called air currents with very little winds or horizontal movement of air. Thus the region is known also as the Belt of calm or Doldrums.

Question 29. Rain-shadow area.
Answer: After shedding orographic rain on the windward side of a mountain, the dry, cold wind overcomes the mountain and blows down the leeward side (i.e., the opposite slope of the windward side). There is very little moisture left in the air as most has been shed on the windward side.

Moreover, as the wind descends, the temperature of the air rises and so does its moisture-holding capacity. This results in very little of rainfall on the leeward slope, which is thus known as the ‘rain-shadow area’.

Example: The eastern slopes of the Western Ghats, i.e., the interior part of the Deccan Bissau e receive very little of rainfall is known as a rain-shadow area of India.

Question 30. What do you mean by river capture or river piracy?
Answer: River capture is a landform feature developed by a river on its mountain course in which a turbulent river captures the course of another weak river.

It, sometimes, happens on the mountainous course that a river increases its headward erosion and then breaks down the water partings and then captures the weaker river on the other side of the watershed. This action of a river is known as River capture or River piracy.

Question 31. What is oxbow lake?
Answer: Ox-bow lake is a lake-like water body in the shape of an ox-bow, developed by a river on its lower course. It, sometimes, develops where meander takes the shape of the letter ‘S’. The two bends of the S-like meander tend to approach each other by side-cutting. A swift current then cuts through the neck and tends to flow rightly straight. The bend is then left there without flow of running water as an ox-bow lake.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 32. What is a snowline?
Answer: A snowline is an imaginary line on which perpetual snow exists. It is a line on a mountain or hill slope which presents the lower limit of perpetual snow. It may be defined as a line above which the snow does not melt even in summer.

The height of snowlines ranges from sea level around the poles to 5,500 meters or more on mountains of east Africa, near the equator.

Question 33. Why is the Ganga called ‘an ‘ideal river’?
Answer: The Ganga is a typical example of an ideal river. Throughout the entire course, the Ganga presents the distinct characteristic features of the upper course (as on the Himalayas mountains), the middle course (as on the northern plains) and the lower course (as on the deltas) of an ideal river and that is why the Ganga is called an ideal river.

Question 34. What is Iceberg?
Answer: A block of ice which remains floating on the ocean water is known as an iceberg.

It forms when a glacier enters the sea, the ice is buoyed up by the water and a portion of the glacier is easily broken off and floats away. An iceberg is irregular in shape.
Icebergs are found near the Newfoundland coast which comes from the drift by the Labrador current.

Question 35. What is moraine?
Answer: Moraines are fragments of rock materials, consisting of sand, clay, gravel and boulder brought down with the movement of a glacier. They are of several types, such as, lateral moraines, medial moraines, ground moraines, terminal moraines, recessional moraines, etc.

Question 36. How are hanging valleys formed?
Answer: A hanging valley is formed by a tributary glacier. The main glacier forms a much deeper valley than a tributary glacier. After the ice has melted, the tributary valley is left at a higher level than the main valley. Such valleys appear hanging above the main valley and are called hanging valleys.

Question 37. Why do temperatures over land and water surface differ?
Answer: The temperatures over land and water surface differ because land surface gets heated rapidly and cooled rapidly as rocks and soils of the land surface are not good conductors of heat. Oceans/Seas get heated slowly and cooled slowly as water is a good conductor of heat.

WBBSE Class 10 Geography Chapter 2 Question Answer

Question 38. Snow melts more quickly on the south-facing slopes of the Himalayas than on the north-facing slopes – why?
Answer: Areas of steep slopes also show thermal contrast due to the aspect of the slope. Thus in the Himalayas, the south-facing sunny slopes are warmer than the north-facing shady slopes due to which snow melts more quickly on the south-facing slopes of the Himalayas than on the north-facing slopes.

Question 39. Where and why are the trade winds unable to cause rainfall?
Answer: Trade winds are unable to cause rainfall on the eastern margins of the continents because after crossing the continents from east to west they become dry. The western margins of the continents in the tropical zone are deserts like Sahara, Atacama, Kalahari and the western Australian desert because they blow from land to sea.

West Bengal Board Class 10 Geography Chapter 2 Atmosphere 3 Marks Questions And Answers:

Question 1. Briefly explain any three factors to identify the Mediterranean climate in the Temperature-Rainfall graph.
Answer: Three factors to identify the Mediterranean climate in the Temperature-Rainfall graph:

1. Average annual temp: 13°-18°C.
The annual range of temp: is 6° – 16°C. Average
summer temp: 14°-22°C.
Average winter temp: 10°-14°C.

2. Average annual rainfall:35-75 cm.
3. Identification of hemisphere: If the temperature is higher from May to August, the station belongs to the northern hemisphere. If the temperature is higher from November to February, the station belongs to the southern hemisphere.

Question 2. Why does temperature decrease with the increase in altitude in the Troposphere?
Answer: Atmospheric temperature decreases with an increase in altitude for the following reasons:

1. Insolation first heats up the earth’s surface. This heat is radiated into the atmosphere, gradually heating the layers from bottom to top.
2. The upper layers of the atmosphere are less dense and can rapidly radiate out heat and get cooled.
3. Pressure is less in the upper levels of the air, hence their heat absorbing capacity is also less.

Question 3. Discuss the differences between sea breeze and land breeze.
Answer: Differences between sea breeze and land breeze:

Sea Breeze	Land Breeze
1. It blows during the daytime.	1. It blows during the nighttime.
2. It blows from the sea towards the land.	2. It blows from the land towards the sea.
3. It happens due to unequal heating of land and sea.	3. It happens due to unequal rates of radiating heat by land and sea.

Question 4. Why does the sky appear blue?
Answer: The decrease in temperature in the lower atmosphere occurs because it cannot absorb all the incoming light equally. It tends to allow red colours (wavelengths), and this is the reason why the sky appears blue. Again, heat energy from the sun reaches the earth’s surface as short-wave radiation

which does not heat the air through which it passes. Only about 47% of solar energy reaches the earth’s surface, and 17% of it is reflected back into the atmosphere from snow and water surfaces.

Thus only about one-third (34%) of the total energy entering the atmosphere actually warms the earth’s surface. This heat is passed back into the atmosphere from the earth’s surface as long-wave radiation heating the lower atmosphere.

Question 5. Describe the role of water vapour in the weather processes.
Answer:
Water Vapour: Water vapour is the result of evaporation from water bodies on the earth. Water vapour represents about 2 per cent of the air by volume. The presence of water vapour in the atmosphere is of primary importance in weather phenomena.

1. It reduces the amount of insolation reaching the earth’s surface by absorption.
2. It acts like an insulating blanket by preserving the earth’s radiation. It allows the earth to become neither too cold nor too hot.

Class 10 Geography Chapter 2 Notes WBBSE

3. Water vapour is the basic cause of all condensation and precipitation.
4. The presence of most of the water vapour in this layer is responsible for condensation, clouds and precipitation.

5. Dust particles give rise to fog, clouds, smog, etc. in this layer.
6. Convection currents are confined to this layer for the heating and cooling of the atmosphere.
7. The air is unstable in this zone and gives rise to atmospheric disturbances like cyclones.

Question 6. What is the significance of dust particles in the atmosphere?
Answer:
Significance of Dust particles in the Atmosphere: The sources of these dust particles include dry deserts, lime beds, beaches, dry river beds, volcanic eruptions and meteors.

But particles are important due to the following reasons:
1. These play an important part in the heating and cooling of the atmosphere.
2. These affect insolation by the processes of scattering and absorbing sun rays.
3. The dust particles serve as hygroscopic nuclei for the condensation of water vapour.
4. These are responsible or the formation of clouds, sunset, fog and smog (smoke + fog).
5. It affects the visibility of the atmosphere.

Question 7. Distinguish between mist and fog. Why is visibility so poor in smog?
Answer: Mist and fog are not merely low clouds. Fog forms by cooling of rising air. Mist is the result of air of high humidity (80%) being cooled by passing over cooler ground. The particles of water in the mist are smaller and fewer than those in fog. So visibility is lesser in fog than in mist and it is the least in smog, i.e., smoke mixed with fog.

Question 8. How is air cooled?
Answer: Air is cooled in two main ways

1. By being made to rise:
(1) A wind may move up a mountain.
(2) Hot air may rise by convection.
(3) Warm air may rise over cold air.

2. By passing over a cold surface:
(1) A warm air blowing over a cold ocean current.
(2) A warm air blowing over a cold land surface.

Most of the world’s rain results from the first type of cooling and mist and fog from the second type of cooling.

Question 9. State the favourable conditions for the formation of dew.
Answer: Following conditions are favourable for the formation of dew:

1. Long Nights: Long nights give sufficient time for cooling the earth’s surface and the air touching it. This results in a fall of temperature below the dew point and dew is formed.
2. Clear Sky: Clouds obstruct the incoming and outgoing heat radiations. Clear sky permits sufficient heating and large-scale evaporation during the day. Condensation is caused by cooling at night and dew is formed.

3. Calm Air: If the air is calm, it will remain in contact with the earth’s surface for a long time and cool down to the dew point and dew will be formed.
4. High Relative Humidity: High relative humidity is essential for the formation of dew. Where the humidity is low, dew is not formed even if the temperature falls below the dew point.

Class 10 Geography Chapter 2 Notes WBBSE

5. Dew Point should be higher than Freezing Point: If the dew point falls below the freezing point, we will have frost in place of dew.

Question 10. State the factors affecting relative humidity.
Answer:
Factors Affecting Relative Humidity: Relative humidity depends upon the following two factors:

1. Amount of Water Vapour: If the amount of water vapour in the air increases due to evaporation, the relative humidity increases.
2. Temperature of the Air: Relative humidity increases with the fall of temperature but it decreases when the temperature rises. The relative humidity of saturated air is 100%. A given sample of air can become saturated without any addition of water vapour provided its temperature falls to the required extent. On the other hand, a saturated sample of air can become unsaturated if its temperature rises.

Absolute humidity has no relation with temperature. Suppose one cubic metre of air has 5 grams of water vapour at 10°C temperature. If the temperature of the air is increased, the amount of water vapour will remain the same, provided water vapour from outside is not allowed to enter the air. However, the water vapour holding capacity of the air is increased. In other words, the relative humidity will change but absolute humidity will remain unchanged. This thing becomes clear from the table given below.

Temperature (°C)	Absolute Humidity (Amount of water vapours present)(gm)	(The maximum amount of water vapour the air can hold) (gm)	(Relative Humidity (%) column (1)/ column (2) xl00)
5	7	7	7/7 x 100 = 100.0%
10	7	9	7/9 x 100 = 77.8%
15	7	14	7/14 x 100 = 50.0%
20	7	20	7/20 x 100 = 35.0%
25	7	28	7/28 x 100 = 25.0%

In other words, relative humidity decreases with the rise in temperature but the absolute humidity remains unchanged, or in other words, the temperature is inversely proportional to relative humidity.

Question 11. Write the importance of relative humidity.
Answer:
The Importance of Relative Humidity: Relative humidity is very important in our daily life. Some important points have been mentioned here:

1. Health: People who live in areas which have high relative humidity do not enjoy good health. Even very low relative humidity is not conducive to health as.it increases irritation and produces cracks on human skin. It has been found that a relative humidity of 60% is most suitable for human health. The study of relative humidity is important because it affects the capacity of human beings for work.

2. Forecasting of Rain: It is possible to find out the possibility of rainfall with the help of relative humidity. In fact, the relative humidity rises before rainfall takes place. Meteorologists are able to make forecasts of weather with the help of relative humidity data.

3. Agricultural Operations: It is possible to calculate the rate of evaporation with the help of relative humidity because the humidity is inversely proportional to evaporation. Evaporation has a great effect on the growth of agricultural crops, the health of animals, etc. Hence knowledge of relative humidity is essential to agricultural operations.

4. Building Material: It is necessary to take into account the relative humidity before constructing buildings. Many types of materials begin to ferment in high humidity. When the relative humidity is very low the plasters develop cracks. Building material is selected taking into consideration the relative humidity of the place.

Class 10 Geography Chapter 2 Notes WBBSE

Question 12. State the characteristics of trade winds.
Answer: The trade winds have the following characteristic features:

1. These winds blow from the north to the south in the Northern Hemisphere and from the south to the north in the Southern Hemisphere. But the Coriolis effect and Ferrel’s law explain how these winds are deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. Thus, they flow as the north-eastern trades in the Northern Hemisphere and the south-eastern trades in the Southern Hemisphere. That is why they are known as ‘Easterlies’ also.

2. The trade winds travel from about 30°N and S towards the equator and gradually become hot and dry. As such they do not cause much rainfall. But when they cross ocean water and reach the land, they cause heavy rainfall on the eastern margins of the continents while their western margins remain practically dry.

3. On the eastern margins of the oceans, the trade winds come into contact with cool ocean currents and do not cause much rainfall there.
4. Near the equator, the two trade winds clash with each other and on the line of convergence, they rise and cause heavy rainfall.

5. The trade winds follow a specific path with a speed of 15 to 25 km per hour. The speed is more in winter than in summer.
6. They are converted into monsoon winds in the Indian Ocean.

Question 13. State the characteristics of westerlies.
Answer: The westerlies have the following characteristics:

1. Under the influence of Coriolis force, they blow from southwest to north-east in the Northern Hemisphere and northwest to south-east in the Southern Hemisphere. They are called westerlies because they blow from the western side in both hemispheres.

2. Since they blow from warm areas to cold areas, they cause considerable rainfall, especially on the western margins of the continents.

3. Their flow is irregular and uncertain in temperate lands due to the occurrence of cyclones and anticyclones there.
4. Their westerly flow is obstructed due to the presence of vast land masses of irregular relief in the northern hemisphere.

5. Due to the presence of a vast expanse of oceans in the Southern Hemisphere, the westerlies are much more stronger and more constant in direction. The westerlies are best developed between 40° and 65° south latitudes. Here they are known as Brave West Winds. According to the sound created by westerlies, these latitudes are often called Roaring Forties, Furious Fifties and Shrieking Sixties, which are dreaded terms for navigators.

6. The poleward boundary of the westerlies is highly fluctuating. There are many seasonal and short-term fluctuations.

Question 14. State the characteristics of polar winds.
Answer: Their main characteristics are as follows:

1. They flow from the northeast to SW direction in the northern hemisphere and from the South-east to North-west direction in the southern hemisphere under the influence of Coriolis force.
2. Since they originate from the poles, they are extremely cold winds.

3. They flow from cold areas to comparatively warm areas and do not cause much rainfall. Their capacity to absorb moisture is also very little due to low temperatures.
4. These winds give birth to cyclones when they come in contact with the westerlies. This brings about frequent changes in the weather and heavy rainfall occurs.

Question 15. What are the reasons for prevailing Low pressure at the equator?
Answer: Low pressure prevails there due to the following three reasons:

1. Due to intense heating, air gets warm and rises over the equatorial region and producing the equatorial low-pressure belt.
2. There is high water vapour content in the air which reduces the density of the air. Reduction in density results in lowering the pressure. It is worth noting that the density of moist air is always less than that of dry air.

3. Earth’s rate of rotation is maximum at the equator. This results in maximum centrifugal force at the equator which pushes the air away from the earth’s surface and causes low-pressure conditions.

Question 16. State the favourable conditions for inversion of temperature.
Answer: Following conditions favour inversion of temperature:

1. Long Nights: Insolation is received during the daytime and it is radiated during the night. The earth’s surface cools down at night due to radiation. The air of the lower layer touching the earth’s surface is sufficiently cooled while the air of the upper layer is still warm. Thus, long nights are helpful for the inversion of temperature.

2. Clear Sky: Clear sky is essential for the reflection of heat radiations by the earth’s surface thereby cooling it. Clouds obstruct this reflection and hamper the occurrence of inversion of temperature.
3. Stable Weather: Continuous radiation of heat is possible in stable weather. This condition leads to temperature inversion. Change in weather disturbs the temperature inversion.

4. Dry Air: Moist air has a greater capacity to absorb heat radiation and obstructs temperature inversion. But dry air does not absorb much radiation and promotes temperature inversion.
5. Ice Cover: Areas covered with ice reflect most of the heat radiation and the layer of air touching it becomes cold while the upper air layer remains warm. This leads to temperature inversion.

6. Air Drainage: During long winter nights, the air on higher slopes cools down quickly and becomes dense. It moves down the slope and settles down on the valley bottom by pushing up the comparatively warmer air. Sometimes, the temperature of the air at the valley bottom falls below the freezing point, whereas the air at higher altitudes remains comparatively warm. This is known as ‘Air Drainage Temperature Inversion’.

Question 17. Give three differences between Temperature & Isolation.
Answer:

Insolation	Temperature
1. Insolation is heat energy which makes things hotter.	1. Temperature measures the intensity of heat, i.e., the degree of hotness.
2. Insolation is measured in calories.	2. Temperature is measured in degrees (Celsius or Fahrenheit).
3. Insolation is the cause.	3. Temperature is the effect.

Question 18. What are the harmful effects of ultraviolet rays?
Answer: Harmful Effects of Ultraviolet Radiations:

1. Ultraviolet radiations reaching the earth from the sun are harmful to all life forms on the earth (including man, plants and animals).
2. They cause skin cancer, particularly in fair-skinned people.
3. They cause cataracts and blindness among humans. and animals.
4. They reduce our immunity to diseases, thus, impairing the body’s resistance.
5. They adversely affect crop production and cause food shortages.
6. Rainfall cycle or hydrological cycle is also disturbed by ultraviolet rays.
7. On reaching the earth’s surface the ultraviolet rays cause ecological disturbances.
8. Ozone can affect the earth’s climate by adding to the greenhouse effect.

Question 19. State the characteristics of Ilsotherms.
Answer: Characteristics of Ilsotherms:

1. isotherms run almost parallel to latitudes because the same amount of insolation is received and the same temperature is experienced by almost all points located on a particular latitude.

2. Due to differential heating of land and water, temperature above the oceans and land masses varies even on the same latitude. Isotherms, therefore, bend slightly white crossing from landmass to oceans and vice-versa.

3. There is more water area in the southern hemisphere resulting in uniform temperature distribution. So there are less bends in the isotherms and their east-west trend is more clear in the southern hemisphere as compared to the northern hemisphere.

4. Distance between isotherms indicates the rate of change of temperature. Close spacing of isotherms indicates a rapid change in temperature and wide spacing means slow to change.
5. Temperature is always high in the tropics and isotherms of high value are located there. Very low temperature is experienced by polar areas and isotherms of low value are found there.

Question 20. State the effects of global warming.
Answer: Effects of Global Warming are:

1. Global temperature is likely to rise by 2°C to 5°C during the next century.
2. Due to the rise in temperature by 2°C to 5°C, there is a chance of the melting of ice caps on Earth’s poles. This melting of ice will result in the rise of the sea level. Large stretches of low-lying areas will submerge and many island countries will face deep encroachment by seawater. Some may disappear altogether.

3. As the increase in temperature will be uniform all over the surface of the world, there will be serious climatic changes. This will bring various changes in wind and rain patterns.
4. Higher temperatures will cause a rise in transpiration, which in turn, will affect the groundwater table.
5. As the climatic belts shift from the equator towards the pole, the vegetation would also shifts away from the equator.
6. Insects and pests will increase in warmer climatic conditions. Thus, pathogenic diseases will multiply.

Question 21. State two scales used to measure temperature. State their relation also.
Answer: Thermometers are used to measure temperature. There are two scales used to measure temperature — the Centigrade Scale and the Fahrenheit scale.

The centigrade scale has 100 divisions while the Fahrenheit scale has 180 divisions. One scale can be converted to the other with the help of the conversion formula:

Question 22. Discuss the different ranges of temperature.
Answer:
Ranges of Temperature: The difference between the maximum and the minimum temperatures on any one day is termed as the Diurnal Range of Temperature. Starting from sunrise, the temperature shows a gradual increase until mid-day and then remains fairly constant for a couple of hours before beginning to fall again.

Though the angle of incidence is maximum around noon, the maximum temperature is re- corded at about 3 p.m. This is because the heating of the atmosphere takes place from below and consequently there is a time lag.

The Mean Monthly Temperature is the average of mean temperatures of all the days in the month. In the Climate Data, the mean monthly temperature is calculated on the basis of average values of the mean temperature of the days for each month. The Mean Annual Range of Temperature is the seasonal difference in temperature or the difference between the mean temperature of the hottest month and the mean temperature of the coldest month.

Question 23. State three factors determining rainfall.
Answer: The same factors that determine climate also determine the amount of rainfall because there is a close relationship between moisture in the atmosphere, pressure and temperature. However, three chief factors are:

1. Land-sea contrast: Because water vapour rises from oceans, sea coasts receive more rainfall than the interior of the continents.
2. Direction of winds: Prevailing winds blowing from ocean to land bring more rainfall than winds blowing from the land.
3. Presence of mountains: Mountains force the winds to shed moisture on the windward side and the leeward side generally remains dry.

Question 24. Define absolute humidity and relative humidity.
Answer:
Absolute humidity: The total amount of water vapour in a definite volume of air at a particular temperature is called absolute humidity.
Relative humidity: The ratio between the absolute humidity and the amount of moisture that the same volume of air can hold at that temperature is called relative humidity.

Question 25. Differentiate between Absolute Humidity and Relative Humidity.
Answer:

Absolute Humidity	Relative Humidity
1. It is the measure of the weight of water vapour that is present in a given volume of air and is expressed in grams.	1. It is simply the ratio between the amount of water vapour in air at a given temperature and the maximum amount of water vapour that the air could hold at that temperature and is expressed as a percentage.
2. A.H. determines the amount of precipitation.	2. But R.H. indicates whether there will be any precipitation or not.
3. It may not change throughout the day.	3. It varies with the daily temperature.

Question 26. Differentiate between the troposphere and the stratosphere.
Answer:

Troposphere	Stratosphere
1. It is the lowest layer of the atmosphere.	1. It is the second layer of the atmosphere above the earth.
2. Its height varies from 8 km at the poles to 20 km at the equator.	2. Its height varies from 16 km at the equator and 72 km at the poles.
3. In this layer the temperature decreases at the rate of 1°C per 165 metres.	3. Temperature is very low and fairly constant in this layer.
4. It is a zone of convectional currents.	4. It is the non-convective zone of the atmosphere.
5. Most of the water vapour and dust particles are found in this layer.	5. Cloud, dust particles are practically absent in this layer.
6. Atmospheric disturbances are confined within this zone.	6. This zone is free from atmospheric disturbances.

Question 27. Write in short about the temperature belts of the world.
Answer: The earth is divided into 5 temperature zones.

They are:
1. One Torrid zone
2. Two Temperate zones and
3. Two Frigid zones.

1. One Torrid Zone: The 27° celsius isotherm lines on both sides of the equator determine the boundaries of the torrid zone. This zone receives maximum sunshine around the year,
2. Two Temperate Zones: The areas between the 27-celsius isotherm line and the 0-celsius isotherm line on both hemispheres constitute the two temperate zones.

3. Two Frigid Zones: The areas covering from 0 isothermal lines to the poles on both the hemisphere comprise the two frigid zones.

Question 28. Differentiate between weather and climate
Answer:

Weather	Climate
1. Weather stands for actual atmospheric conditions for a short period-a day or two.	1. Climate is the aggregate of atmospheric conditions for a longer period.
2. The weather change from day to day and can not be generalized.	2. The climate is ever-lasting and fixed, it does not change so frequently.
3. Weather is actually present at a place It is what you get.	3. Climate is what you expect. It is arrived at by climatic means or average.
4. Every type of weather can occur at one place.	4. A particular place can not have all types of climate.
5. Weather refers to a particular place.	5. But climate refers to a particular area.
6. Weather deals with the individual elements of weather.	6. But climate deals with the combination of all the elements of weather.

Question 29. What do you know about the composition of the atmosphere?
Answer: The atmosphere is mainly composed of three elements:

1. Gases,
2. Water vapour and
3. Dust particles.

1. Gases: Nitrogen and oxygen are the two major gases found in the atmosphere. About 99% of the atmosphere consists of these two gases. Nitrogen occupies 78% and oxygen occupies nearly 21% of the atmosphere by volume.

The remaining 1% consists of a number of gases like Argon, Carbon dioxide, Neon, Helium, Krypton, Hydrogen, Xenon, etc.

2. Water Vapour: The amount of water vapour varies from place to place and from time to time.
3. Dust particles: Air also contains tiny dust particles which are mainly found in the lower atmosphere. They are rarefied in the higher level.

Question 30. Explain the condition for the formation of rainfall.
Answer: The rains are drops of water which fall down on the ground from the clouds.

Formation of Rainfall: The main cause of rainfall is the cooling of saturated water. The mechanism involved in it passes through a number of stages:

1. Air should have plenty of water vapour,
2. Air should be saturated with moisture,
3. Air should get cooled or get the chance to come in contact with the cold air for condensation and
4. Condensation of water vapour makes droplets.

They together form clouds. Thus clouds are made of water droplets or ice particles. These cloud (particles) droplets coalesce (merge) to form raindrops. When these raindrops become heavy, air cannot hold them, and due to the gravitational pull of the earth, they fall on the ground in the form of raindrops.

Question 31. Westerlies cause heavy rainfall. Why?
Answer: Westerlies come from a hot place. So, they have a good capacity to hold water. While coming to a place they blow over the water bodies and pick up lots of moisture. As they arrive in a cooler region, their water-holding capacity shrinks giving rise to heavy rainfall. Hence, westerlies cause heavy rainfall.

Question 32. State the importance of water vapour in the atmosphere.
Answer: Water vapour has immense importance due to:

1. Presence of water vapour in the air causes clouds to form and rain to occur.
2. It is also the source of all forms of precipitation.
3. It absorbs heat and keeps the surrounding air warm.
4. It has an important role in determining the climate of a region.

Question 33. What do you know about Tropopause, Stratopause and Mesopause?
Answer:
Tropopause: The upper limit of the tropopause is called tropopause and at this boundary, the fall in temperature with increasing height stops.

Stratopause: The upper limit of the stratosphere is called stratopause and it is about 50 km above the ground.

Mesopause: The upper. limit of the mesosphere is called mesopause. The temperature falls to about 100 C at this mesopause.

Question 34. State the conditions necessary for precipitation.
Answer: Following conditions are necessary for precipitation:

1. There should be plenty of water vapour in the atmosphere in the adjoining areas. This is possible only when there is great evaporation in the neighbouring seas or oceans.
2. The oceanic winds should blow towards the land to transfer vapour-laden air from the ocean to the land, where the rainfall is to occur.
3. The process which can induce the vapour-laden air masses to rise to higher altitudes for cooling and condensation.

Question 35. Mention the different characteristics of the troposphere.
Answer: Of all the layers of the atmosphere, the troposphere is the most important in climatology due to its following characteristics :

1. All the weather-making processes are confined to this layer.
2. Great contrasts in climate and weather are observed in different areas due to changes in temperature in this layer.
3. The presence of most of the water vapour in this layer is responsible for the condensation of clouds and precipitation.
4. Dust particles give rise to fog, clouds, smog, etc. in this layer.
5. Convectional currents are confined to this layer for the heating and cooling of the atmosphere.
6. The air is unstable in this zone and gives rise to atmospheric disturbances like storms, and cyclones.

Question 36. Write the causes for the inversion of temperature.
Answer: Generally there is a decrease in temperature as we ascend upward above sea level, but sometimes temperature increases as we ascend upward. This is known as “Inversion of temperature” or “Lapse rate of temperature”. The causes for the inversion are :

1. When in the calm and cloudless sky in the mid-latitude area, the radiation is swift or when a warm air current flows on a cold surface area of the earth.
2. On the upper slope of the mountain when radiation is rapid and the cold wind resembles the cold water or blows ina the valley due to gravitation,

Question 37. State the characteristics of Cyclones and anticyclones.
Answer:
Cyclone:
1. Cyclone has low pressure at the centre.
2. It blows towards the centre of low pressure from all sides.
3. In the Northern hemisphere it moves anti-clockwise, in the Southern hemisphere it moves clockwise.
4. On reaching the centre of low pressure it moves upwards.
5. Rainfall occurs at the centre of the cyclone.

Anti-cyclone:
1. Anti-cyclone has higher pressure at the centre.
2. It blows in all directions from the centre.
3. In the Northern hemisphere it blows clockwise in the Southern hemisphere it blows anti-clockwise.
4. It moves downwards.
5. It does not produce rain, rather it brings fair weather.

Question 38. Distinguish between the land breeze and sea breeze.
Answer:

Basis	Land Breeze	Sea Breeze
1. Definition	A cool periodic wind blows from land to ocean in coasts.	A cool periodic wind blows from the ocean to land in the coasts.
2. Cause	A low-pressure situation on the ocean.	A low-pressure situation on land.
3. Time	Night, after sunrise it disappears.	Day, after sunset it disappears.
4. Nature	Weak.	Strong.
5. Expanse	Limited in the sea.	Reaches the interior of the continent.
6. Effect	Clear sky, weak anti-cyclones.	Cloudiness and weak cyclones.

Question 39. Differentiate between Trade winds and Westerlies.
Answer:

Trade winds	Westerlies
1. The winds blowing in both the hemispheres From the sub-tropical high-pressure belts towards the equatorial low-pressure belts are called Trade winds.	1. The winds blowing in both the hemisphere from sub-tropical high-pressure belts towards subpolar low-pressure belts are called Westerlies.
2. The direction of these winds in the Northern hemisphere remains from the northeast towards the southwest and in the Southern hemisphere from the southeast towards the northwest. Therefore, they bring rainfall at the Eastern coast of the continents through the Western coast remains almost dry.	2. The direction of these winds in the Northern hemisphere remains from southwest towards the northwest and in the Southern hemisphere from the northwest towards the southeast. Therefore, they bring rainfall at the western coast of continents though the eastern coast remains dry.
3. They show consistency in blowing. Thus these winds were helpful as backing winds to sailing ships in past.	3. These winds blow inconsistently. Sometimes they blow with low strength and sometimes with greater strength, especially in the winter season.

Question 40. Describe the mechanisms of any two types of rainfall.
Answer:
1. Orographic or relief rainfall: Orographic rainfall occurs when moisture-laden winds are cooled due to ascent along a mountain slope or a plateau barrier. As it rises, the moist wind comes in contact with the cool upper atmosphere. As a result, the moist air condenses and rainfall occurs. When the winds go to the opposite side of the hills, plateaus, etc.

They are left with little water vapour. Therefore, the rainfall is much less on the opposite side. The slope which gets maximum rainfall is referred to as the windward side and the side which gets little rain is called the leeward side or rain-shadow region. Since this type of rainfall is caused by the relief of the land, it is known as relief rainfall.

2. Cyclonic rainfall: This type of rainfall is caused by the convergence of warm and cold air masses along a front. It occurs when a moisture-laden warm air current and cold air current approach each other from opposite directions. The moist air climbs up the cold air along the meeting line called a front. The air expands, cools and finally, rain and cyclones occur.

Question 41. Why are cloud-free nights colder than clouded nights?
Answer:
Cloud-free nights are colder than clouded nights: During the day, the earth is heated by the sun. If the skies are clear, more heat reaches the earth’s surface. This leads to warmer temperatures.

However, if skies are cloudy, some of the sun’s rays are reflected off the cloud droplets back into space. Therefore, less of the sun’s energy is able to reach the earth’s surface, which causes the earth to heat up more slowly. This leads to cooler temperatures.

When forecasting daytime temperatures, if cloudy skies are expected, forecast lower temperatures than you would predict if clear skies were expected. At night cloud cover has the opposite effect. If skies are clear, the heat emitted from the earth’s surface freely escapes into space, resulting in colder temperatures.

However, if clouds are present, some of the heat emitted from the earth’s surface is trapped by the clouds and re-emitted back towards the earth. As a result, temperatures decrease more slowly than if the skies were clear.

When forecasting nighttime temperatures, if cloudy skies are expected, forecast warmer temperatures than you would predict if clear skies were expected  They show consistency in blowing. Thus these winds were helpful as backing winds to sailing ships in past.

Chapter 2 Atmosphere 5 Marks Questions And Answers:

Question 1. Give an account of the atmospheric layers of the Troposphere and Stratosphere.
Answer:
Troposphere: This layer extends up to 16-18 km from the earth’s surface over the equator. It is the layer which is connected with the earth’s surface.

1. All the weather-making processes are confined to this layer.
2. Great contrasts in climate and weather are observed in different areas due to changes of temperature in this layer.

3. The presence of most of the water vapour in this layer is responsible for the condensation of clouds and precipitation.
4. Dust particles give rise to fog, clouds, smog, etc. in this layer.
5. Convectional currents are confined to this layer for the heating and cooling of the atmosphere.

Stratosphere: This layer is found up to a height of 50 km above the Troposphere. There is no formation of clouds in this layer and thus there is no weather. There does not exist any danger of the storm. That is why this layer is ideal for aircraft.

1. It is the second layer of the atmosphere above the earth.
2. Its height varies from 16 km at the equator and 72 km at the poles.
3. Temperature is very low and generally increases in the upper part of the layer.
4. It is the non-convective zone of the atmosphere.
5. Cloud, dust particles are practically absent in this layer.

Question 2. Explain the factors responsible for the formation of equatorial low-pressure belts and polar high-pressure belts.
Answer:
Pressure Belts: The atmosphere is immensely heated due to high temperatures. The landmass is heated through insolation and the air close to the surface is heated through conduction. The heated air moves upwards giving place to low pressure.

Thus, a vacuum is created to fill the gap air from a low-temperature area, i.e., air from a high-pressure region comes. Thus, the winds blow from high-pressure areas to low-pressure areas.

1. Equatorial low-pressure belt: All along the equator and between 5° north and 5° south of the equator, a low-pressure belt exists. This is due to

(1) The vertical rays of the sun throughout, intense heat is caused. The hot air rises upwards as convection currents and expand,
(2) Presence of a large amount of water vapour makes the air lighter and
(3) rotational force of the earth throws the air from the earth’s surface to make the pressure light. The movement of air is not horizontal but vertical these ascending air are called air currents with very little winds or horizontal movement of air. Thus, the region is known also as the Belt of Calm or Doldrums.

2. Polar High-Pressure Belt: Around the North Pole and South Pole high pressure belts are found due to extreme cold, and very little centrifugal force. Here the region is frozen throughout the year and the temperature is always low.

Question 3. Give an account of the occurrence of orographic rainfall with a suitable example and diagram.
Answer:
Orographic or Relief rain: When clouds on their way dash against hills, plateaus, etc., they rise up. Higher up the clouds condense and then rain falls on the slopes of the mountain and the plateaus. When it goes to the other (opposite) side of the hills, plateaus, etc., it is left with little water vapour.

Therefore, the rainfall is much less on the opposite side. This type of rain is called relief rain as it is caused mainly due to the relief of the land. The opposite side of the hill where the rainfall is much less is called the rain shadow area. The Deccan plateau is an example of a rain-shadow region in India. Orographic or Relief rain

Question 4. Explain with sketches the origin and direction of planetary winds of the world.
Answer: There are three types of planetary winds:

1. The Trade winds,
2. The Westerlies,
3. The Polar winds.

1. The Trade winds: Winds that blow from the Sub-tropical high-pressure belts to the Equatorial low-pressure belts are called Trade winds. According to Ferrel’s law, due to Coriolis force, caused by the earth’s rotation, winds deflect to the right in the northern hemisphere and to the left in the southern hemisphere.

Hence, the winds are called northeast trade winds in the northern hemisphere and the southeast trade winds in the southern hemisphere. The velocity of NE trade winds is around 16 km per hour and that of SE trade winds is 22 km per hour (due to fewer landforms and vast oceans).

2. The Westerlies: The winds blowing from the sub-tropical high-pressure belts to the sub-polar low-pressure belts are called Westerlies. As the director of the Westerlies is opposite to that of trade winds, they are also called Anti-trade winds. In the northern hemisphere, they blow from the southwest and in the southern hemisphere, they blow from the North-West.

3. The polar winds: The chilled winds blowing from the polar regions to the subpolar low-pressure regions are called the polar winds. Since their direction is similar to that of Trade winds, they are also called Polar Easterlies or Polar Trade winds. In this region, the deflection of winds is so high that they appear to blow almost from the east.

Question 5. Discuss the major characteristic features of Tropical Monsoon climatic regions.
Answer: The word monsoon is derived from the Arabic word Muslim meaning season. The monsoon wind is a seasonal wing as it is very much associated with rain, it invariably means the rainy season. Characteristics of this climatic region are stated below:

1. The monsoon winds change their direction according to seasons (in summer and in winter).
2. The summer monsoons bring rains as they come from the seas winter, monsoons remain rainless as they generally blow from the land.
3. Summers are hot and wet, and winters are pleasantly warm and almost rainless.
4. The summer temperature ranges between 27°C and 32°C.
5. The winter temperature varies between 13°C and 22°C.
6. The range of temperature between day and night, and between summer and winter is considerably wide; it is about 10°C to 15°C.
7. The rains come in the latter half of summer.
8. The amount of rainfall varies from place to place according to landform features. Generally, this region has an average rainfall between 100 cm and 200 cm.

Question 6. Explain three major factors responsible for temperature variation in the atmosphere.
Answer: Three major factors responsible for temperature variation in the atmosphere are as follows:

1. Latitude: The latitudes exercise the most dominant control over the duration of the sunshine and thereby the length of the day. The higher is the latitude, the lower is the amount of heat received.
2. Altitude: By the normal lapse rate, temperature decreases by 64°C with every 1km rise in altitude. Hence, higher altitude places are colder than lower regions.

3. Distribution of land and water bodies: Heat-absorbing capacities of land and water bodies are not equal. The latent heat capacity of water is more compared to land. Hence, extremes of temperature are noticed on land, while water bodies show a moderate range of temperature.

Question 7. Give an account of the major climate regions of the world with respect to their natural vegetation, temperature, air pressure, rainfall & human activity.
Answer: The following table presents the scheme of the world’s climatic types with their seasonal temperature, air pressure, rainfall, natural vegetation and human activities:

Question 8. State the factor affecting the rate of evaporation.
Answer: The process by which water is transformed from liquid to vapour or gas is known as evaporation. The water vapour suspended in the earth’s atmosphere is the result of evaporation. Approximately 600 calories of energy are required to convert one gram of water vapour without any change in the temperature. This is known as latent heat. The rate of evaporation keeps on os from place to place and from time to time.

The following factors affect the rate of evaporation:
1. Temperature: An increase in temperature increases the water absorption and retention capacity of air. As such, air with higher temperature is capable of more evaporation as compared to air of lower & temperature. Evaporation in the tropical zone is much higher than in the polar zone because the temperature prevailing in the top Evaporation is higher in summer than in winter due to temperature differences. Similarly, evaporation is higher during the day as compared to night.

(1)Dryness of Air: Dry air has a larger potentiality of absorbing and retaining water vapour as compared to wet air. So evaporation by dry air is larger than that by wet air. It is on account of this reason that evaporation is higher in dry season than in the rainy season.

(2)Clouds: Clouds act as blankets for incoming solar radiation and obstruct evaporation. Thus, a clear sky is essential for evaporation.
(3)Size of the Water Area: The larger the size of the water area, the larger the amount of evaporation.
(4)Movement of Air: The movement of air replaces the saturated layer with the unsat- curated layer which has a greater capacity of absorbing moisture. Hence, the greater the movement of air, the greater is the evaporation.

Question 8. Distinguish between temperate cyclone & tropical cyclone.
Answer:

Temperate Cyclones	Tropical Cyclones
1. Temperate cyclones develop in temperate lands.	1. Tropical cyclones originate and grow in the tropical zone.
2. Temperate cyclones can develop both on land and at sea.	2. Tropical cyclones mainly originate in the sea and they disappear after crossing over to land.
3. They are more active in the winter season.	3. They are more active in the summer season.
4. The isobars in a temperate cyclone are elliptical.	4. The isobars in a tropical cyclone are circular.
5. They are large in size with their diameter varying from 800 to 1600 km.	5. They have a small size and their diameter varies from 150 to 750 km.
6. Pressure gradient is gentle.	6. Pressure gradient is steep.
7. Wind velocity is less, say 30-40 km/hour.	7. Wind velocity is more, about 100 to 200 km/hour,
8. Temperate cyclones move from the west.	8. Tropical cyclones move from east to west.
9. Rainfall is light but widespread.	9. There is torrential rainfall which is concentrated over a small area.
10. Rainfall continues for several days.	10. Rainfall stops after a few hours.

Question 9. Describe the major temperature belts or heat zones of the world.
Answer:
World’s Heat Zones: We can divide the earth into five zones on the basis of the heat received from the sun; they are one Torrid zone, two Temperate zones (the north and south temperate zones) and two Frigid zones (the north and south frigid zones).

(1)The Torrid or the Hot Zone: The Torrid or the Hot zone lies between the Tropic of Cancer and the Tropic of Capricorn It is the hottest part of the earth. The equator runs through the middle of this zone. The sun shines over this region more or less vertically throughout the year.

(2-3) The Temperate Zones: The North Temperate zone lies between the Arctic Circle and the Tropic of Cancer. The South Temperate zone lies between the Antarctic Circle and the Tropic of Capricorn. This is a zone of moderate climate. The sun is never overhead in this region. The summers are not very hot, nor are the winters very cold. That is why they are known as temperate zones.

(4-5) The Frigid or the cold zones: The North Frigid zone lies between the Arctic Circle and the North Pole. The South Frigid zone lies between the Antarctic Circle and the South Pole. In these zones, the sun- rays are always very slanting so these are the coldest parts of the earth. Summers are very short and cold. Winters are long and extremely cold. Land remains frozen throughout the year.

Question 10. (1)Explain the mechanism of the movement of wind and mention its importance as a controller of weather and climate. (2)Classify wind.
Answer: Mechanism of Movement of wind: Winds do not blow in a straight line. They change their directions while blowing. This is due to the rotational movement of the earth.

In the northern hemisphere, they deflect to the right, while in the southern hemisphere, they deflect to the left. This rule is known as Ferrel’s law. The deflection is the least on the equator, but it goes on increasing towards the poles.

The wind controls the weather and climate of a place to a great extent.
1. Sometimes, it reduces the temperature of a place, and sometimes, it brings moisture (water vapour) from the seas for making rain.
2. A wind from the sea lowers the summer temperature and raises the winter temperature.
3. A wind from the land lowers the winter temperature. The out-blowing cold winds from central Asia cause a cold wave in winter in North China.
4. Distribution of rainfall is controlled by the wind system over the earth. Land winds are dry, on-shore winds are moist and they offer rainfall.
5. Winds bring changes in temperature and rainfall which form together the basis of climate division from place to place.

Classification of Wind: There are different types of wind. They may be classified into the following four major types:
(1)Planetary winds (e.g. the Trade winds, the Westerlies, the Polar winds),
(2)Periodical winds (i-e., the Land Breeze, the Sea © Breeze, the Monsoon, etc.),
(3)Local winds (i.e., the Loo, the Chinook, the Fohn, etc.) and
(4)Sudden or Irregular winds (cyclone and anti-cyclone).

Question 11. What are the effects of global warming?
Answer: Effects of Global warming:

(1)Melting of the caps and glaciers: An increase in the average temperature of the atmosphere affects permanently frozen areas. The lower altitudes will heat up, melting too much snow, thus reducing the length of glaciers.

(2)Increase in sea level: The melting of snow will cause the excess formation of water, which will raise the sea level. In the last century, the sea level was raised by 10-12 cm due to an increase of temperature by 1°C. This will drown coastal areas and islands, hamper the ecosystem, disturb the natural fluvial cycles, change landforms and increase the salinity of rivers.

(3)Change in climate conditions: The amount of precipitation in tropical and hot temperate regions will increase profusely. The northern hemisphere has more land surface, and temperature will increase by 2 or 3 times more than the southern hemisphere. The number of cyclones and thunderstorms will increase. There will be droughts, floods and long summers.

(4) Effects on natural vegetation and agriculture: Many species of coniferous and mangrove trees may get endangered. The crop calender will change. Although the production of corn, sugarcane, jowar, bajra, etc. may increase, the production of wheat, rice, oats, barley, soybean, tobacco, cotton, jute, etc. will decrease. The attack of pests on crops will increase.

(5) Increase in diseases: More numbers of viruses and bacteria will get activated due to heat. Immunity of human beings will get reduced and hence these germs will cause more diseases. Heat strokes and heart attacks will also increase.

(6) Extension of deserts: Destruction of vegetation due to excessive heat will make the soil barren and infertile. This will cause the spreading of deserts extensively.

(7) El-Nino: El-Nino refers to large-scale ocean-atmosphere climatic interaction linked to periodic warming in sea surface temperatures across the central and east-central Equatorial Pacific Ocean. The El-Nino disturbs the global distribution of rain- fall and temperature and also affects the seasons.

(8) Imbalance in earth’s incoming and outgoing solar radiation: The greenhouse gases will arrest excessive heat which will not be released within the day, before the next insolation and keep the atmosphere warm. Hence, there will be a disparity in incoming and outgoing solar radiation.

Question 12. Discuss the factors influencing air pressure.
Answer: Atmospheric pressure varies both vertically and horizontally. The following factors influence the atmospheric pressure –

(1)Altitude: With the increase in height from the sea level, the density of air decreases. So, the weight of air is lower. Thus, from the sea level air pressure lowers by 34 millibars for every 300 m ascent. Adjacent to high mountains air pressure is low so the air is light. E.g.-At the top of Mt. Everest, the air pressure is about 2/3 times less than the sea level.

(2)Temperature: Air temperature has a very close relation with air pressure.

1)When the air temperature decreases air pressure increases When the air temperature falls air becomes cold and dense and hence exerts more pressure. E.g.In the polar regions, excessive cold causes high pressure.

2)When the air temperature increases air pressure decreases: When the air temperature rises the air becomes light and its volume increases hence it exerts less or low pressure. E.g.-In the equatorial region air temperature is high so air pressure is low.

(3)Water Vapour: Water vapour is lighter than air. Water vapour-containing air is lighter than dry air. Hence it exerts high pressure. In the monsoon, season air contains lots of water vapour so it exerts less pressure.

(4)Earth’s rotation: The rotation of the earth and centrifugal force deflect the air. Due to this deflection, the pressure varies. The sub-polar low-pressure belt is due to the rotation of the earth.

Question 13. Explain the relation between pressure and wind.
Answer: Generally, winds blow from regions of high pressure to regions of lower pressure. It is said that winds blow down the barometric slope or pressure gradients. It refers to the rate and direction of change in pressure. Actually, the barometric slope determines the wind direction.

If the difference in pressure between two adjacent regions becomes very high, it is called a steep barometric slope. But if it is low, a weak barometric slope is formed. When the barometric slope on the pressure gradient is steep, the wind blows rapidly when it is weak, the wind becomes weak. So the velocity of wind is determined by the degree of steepness of the barometric slope.

Ferrel’s Law: Winds do not move straight down a pressure gradient. If the earth did not rotate on its axis, winds would follow the direction of the pressure gradient. Earth’s rotation produces the Coriolis force which tends to deflect the winds. The direction of the deflection is stated in Ferrel’s Law A body, moving in the northern hemisphere, will a Sit be deflected to the right and in the southern hemisphere will be deflected to the left”.

Buys Ballot’s Law: Buys Ballo law states: Stand with your back to the wind in the northern hemisphere, the low pressure will be towards your left and the high pressure towards your right, and the reverse applies in the southern hemisphere.

Question 14. State the importance of atmosphere.
Answer:
(1)Insulator: It acts as a shield and protects all living bodies on the earth from the direct rays of the sun and thus prevents the earth from becoming too hot. As a blanket of air, the atmosphere serves as an insulator, maintaining the livable temperatures we experience on earth.

(2)Pressure: Held to the earth by gravitational attraction atmosphere envelops the earth. Although it is not as dense as either land or water, it has weight and exerts pressure. Such phenomena help us to stand, move and walk freely on the earth.

(3)Basic materials of life: The atmosphere sets in a constant turnover of certain basic materials which are vital to the development and maintenance of life on earth.

1)It provides Oxygen a vital gas.
2)It also provides other important gases like Nitrogen (the largest proportion of air), Carbon dioxide (helps in photosynthesis), Ozone (protects the earth from UV rays), etc.
3)It provides water vapour, a vital variable gaseous constituent.
4) Oxygen, CO, and O, influence weather conditions. They absorb small amounts of solar energy and act as temperature regulators. (e) Dust particles present in the atmosphere act as Hygroscopic Nuclei.

(4)Earth’s water cycle: The water cycle of the earth is maintained through the atmosphere.

(5)Other importance:
1) The atmosphere serves as a shield to protect us from showers of meteors.
2) Sound travels by the molecules of the atmosphere. Hence, we can talk and hear.

Question 15. Classify different types of winds with examples.
Answer: Winds are generally classified into four major categories, i.e.,

1. Planetary winds or permanent winds: Permanent planetary winds are the winds blowing uniformly throughout the year. They are the planetary system of winds. They are of 3 types:

(1) The trade winds: The word trade has been derived from the word ‘trader’ which means ‘track’ or ‘regular path’. The winds which blow permanently from a sub-tropical high-pressure belt to equatorial low pressure between 30 N and S attitudes along a definite path along the same direction are called trade winds.

(2) Westerlies: The winds which blow from the high-pressure belt of Tropic of Cancer and Tropic of Capricorn to the low-pressure belt of sub-polar regions of North and South respectively, are known as Westerlies.
(3) Polar winds: The winds which pat from the polar high-pressure belt are called polar winds.

2. Periodic winds: The winds which blow from time to time or in a certain season of the year are called periodic winds. There are of 3 types:

(1)Land breeze: Winds blowing from land to sea at night.
(2)Sea breeze: Winds blowing from sea to land during the day.
(3) Monsoon winds: Winds originated due to differential heating.

3. Local winds: Winds produced due to local temperature or atmospheric variations are called local winds. They occur for short periods of time. Some of them are:

(1)Hot winds: Sirocco, Chinook, Foehn, Santa Ana, etc.
(2)Cold winds: Blizzard, Pampero, Mistral, Bora, etc.

4. Sudden or irregular winds: Due to atmospheric disturbances sometimes there blow irregular winds of great speed called sudden or irregular winds. They are Cyclones, Tornadoes, Hurricanes, Anti-cyclones, etc.

Question 16. Define local wind. Describe some local winds in brief.
Answer: Winds ‘produced due to local temperature or atmospheric variation are called local winds. Some of the important local winds are:-

1. Hot winds:
(1)Sirocco: It is a very hot dry wind of the Sahara desert. It blows from Sahara to the Mediterranean region. It is known as Khamsin in Egypt, Harmattan on the Guinea coast of West Africa and Sirocco in Sicily.

(2)Chinook: Chinook is a warm and dry wind which blows on the leeward slope of the eastern Rockies in the USA and Canada.

(3)Foehn: Foehn is a warm dry wind on the leeward slope of the northern Alps in Switzerland.

(4)Loo: Loo is a hot wind which blows usually in the afternoon in the plains of northern India during May and June.
(5)Santa Ana: This hot and dry wind is experienced in Southern California where it blows from the Santa Ana canyon towards coastal lowlands.

2. Cold winds:
(1) Blizzard: Blizzard is a violent stormy cold polar wind laden with dry snow and is experienced in the north and south polar regions.
(2) Mistral: The Mistral is the name given to the strong, cold northernly wind experienced on the shores of the northwest Mediterranean region.

(3)Bora: Bora is a cold and dry wind that blows along the Adriatic coast and in northern Italy during winter.
(4)Pampero: It is a north-westerly cold wind in the Pampas grassland region of South America.

3. Storms:
(1) Nor’westers: Nor’westers are violent thunderstorms which occur in areas where deep humid winds from the sea meet hot and dry winds on land. The storms come in the afternoon in the month of April-May in West Bengal, Bihar, Jharkhand and Assam.

Question 17. Define precipitation. State its common forms.
Answer: Precipitation is defined as water in liquid or solid forms falling on the earth. It is a collective name given to various forms of moisture falling on the earth from the condensation of water vapour in the atmosphere.

Its common forms are:
1. Snowfall: When precipitation takes place (below 0°C) in the form of ice crystals or flakes of snow, it is called snowfall. It occurs in temperate and cold regions.
2. Frost: When the temperature of air remains below the freezing point, frost occurs. Frost is, in fact, frozen dew orice formed at or near ground level.

3. Dew: It is a type of precipitation in which water droplets form on the ground or on objects near the ground.
4. Fog: It is a cloud of water droplets suspended in the air at the lower level of the atmosphere near the ground. It limits visibility to less than 100 metres. Fog occurs when water vapour-laden air is cooled below the dew point.

5. Drizzle: Drizzle consists of small raindrops from 0-2 to 0-5 mm in diameter that moves very slowly towards the ground.
6. Sleet: Sleet is partly melted snowflakes or rain and snow falling together. It mainly occurs in temperate and cold regions.

Question 18. Explain in brief the processes by which the atmosphere is heated up.
Answer: The atmosphere is not heated directly by sun rays. First, the earth is heated up by insolation. Then the atmosphere is heated in the following ways:

Radiation: The hot surface of the sun emits heat radiation which strikes the earth’s surface and it gets heated. Then the heated earth also gives off heat radiation into the atmosphere. Thus, the low levels of the atmosphere are heated up.

Conduction: By conduction, the layer of air resting upon the warmer surface of the earth becomes heated. As a continuous process, heat is transferred upward through conduction between 2 immediate layers of air.

Convection: The air adjacent to the earth’s Stee on getting heating by it expands and becomes lighter, so it rises up. Cold air from the surrounding region moves in swiftly to take its place. After this the cold air also gets heated, similarly, it expands, becomes lighter, and rises up to be again replaced by cold air. In this way, heat is transferred to the various layers of the atmosphere and the whole atmosphere gets heated.

Advection: Horizontal transfer of heat is accomplished by advection or the horizontal movement of air and water. Transfer by winds and ocean currents is the most important means of distributing heat from over-heated to heat-deficient areas over the earth as a whole.

Latent heat of condensation: Water vapour holds latent heat. When the water vapour condenses its latent heat is released to the atmosphere. The energy released through this process is known as the latent heat of condensation.

Question 19. Discuss the relationship between earth’s pressure belts and planetary winds with a diagram and examples.
Answer:
Relation between World Pressure Belts and Planetary Wind System:

Atmospheric temperature and atmospheric pressure are inversely proportional. The higher the temperature, the lower will be the pressure. Because heating tends to lower the pressure on the equator, the sun shines, more or less, vertically overhead, resulting in high temperatures in the region. And due to this pressure becomes low. Thus, high temperature means low pressure and vice-versa.

Pressure Belts: The atmosphere is immensely heated due to high temperatures. The landmass is heated through insolation and the air close to the surface is heated through conduction. The heated air moves upwards giving place to low pressure. Thus, a vacuum is created to fill the gap air from a low-temperature area, i.e., air from a high-pressure region comes. Thus, the winds blow from high-pressure areas to low-pressure areas.

1. Equatorial low-pressure belt: All along the equator and between 5° north and 5° south of the equator, a low-pressure belt exists. This is due to:

(1)The vertical rays of the sun throughout, intense heat is caused. The hot air rises upwards as convective currents and expands,
(2)Presence of a large amount of water vapour makes the air lighter and

(3)Rotational force of the earth throws the air from the surface to make the pressure light. The movement of air is not horizontal but vertical. These ascending air are called air currents with very little winds or horizontal movement of air. Thus, the region is known also as the belt of calm or Doldrums.

2. The Sub-Tropical High-Pressure Belts: These belts occur near the tropics and between 25° and 35° latitudes in both hemispheres: The warm air from the equator rises up and blows at high levels towards the poles. But a portion of it cools down and descends in this region. Hence due to descending air currents, the pressure is high in this region.

After the air descends, it becomes warm and the capacity to retain water vapour in the North Pole the air increases, as a result, there is no condensation and rainfall. The climate is dry.

3. Sub-Polar Low-Pressure Belts: Between 60° and 65° latitudes in both the hemispheres, sub-polar low-pressure belts exist. This is mainly due to the centrifugal force due to the rotation of the earth. This is also the belt of convergence of cold polar winds and warm westerlies. Thus, continuous SS formation of cyclones reduces air pressure.

4. Polar High-Pressure Belt: Around the North Pole and South Pole high-pressure belts are found due to extreme cold, with very little centrifugal force. Here the region is frozen throughout the year and the South Pole temperature is always low.

Pressure Belts and Planetary Wind System: Planetary winds can be divided into the following three sections namely:

1. Trade winds or Easterlies: Winds, as a rule, blow from high-pressure areas to low-pressure areas. Thus, the wind blows from sub-tropical high-pressure areas (25° to 30° attitudes in both hemispheres) towards the equatorial low-pressure area.

But due to the rotational movement of the earth (from West and East), these winds are deflected to the right in the Northern hemisphere and to the left in the Southern hemisphere which is also regarded as Ferrel’s law). Thus, the direction of winds in the northern hemisphere is North-East and in the southern hemisphere is South-East. In short, these are known as Easterlies.

In the olden days for traders from Europe to North America, these were the backing winds for their ships. Hence they are also known as Trade Winds.

2. Anti-trade winds or Westerlies: From sub-tropical high-pressure areas (25° – 30°) to sub-polar low-pressure areas (60° – 65°) in both hemispheres the winds blow. According to Ferrel’s law, they deflect towards the right in the Northern hemisphere and towards left in the Southern hemisphere, i.e. they blow from. South-West in the Northern hemisphere and from North-West in the Southern hemisphere.

They are known as westerlies. Because they blow in the direction opposite to trade winds, they are also called anti-trade winds. As they come from the west, they give rainfall to the western coasts.in these latitudes. Again, in the Southern hemisphere due to the absence of big landmasses between 40° and 60° latitudes, these westerly winds blow without any hindrance and with great force or a roar; hence they are known as Roaring forties, Furious fifties and Screeching sixties.

3. Polar winds: From polar high-pressure belts to sub-polar low-pressure belts (60°-65° latitudes in both hemispheres) these winds blow, deflecting to the right in the Northern hemisphere and to the left in the Southern hemisphere. As these winds come from the cold polar regions, they are very cold and dry and blow slowly. The temperature comes down to a freezing point in areas where these winds are prevalent.

Question 20. Describe the different types of rainfall.
Answer: The different types of rainfall are:
1. Convectional,
2. Orographic,
3. Cyclonic.

1. Convectional rain: In the equatorial region, the temperature is very high all year round. There are large oceans So evaporation is very high in this region. There everyday light, hot and humid air moves up, expands and comes in contact with cold air.

The water vapour condenses and clouds are formed. Then there is rain in the equatorial region. This type of rain is called convectional rain because it is due to the convection or upward current of the wind and the rain falls practically all year round.

2. Orographic or Relief rain: When clouds on their way dash against hills, plateaus, etc. they rise up. Higher up the clouds condense and then rain falls on the slopes he mountain and the plateaus. When it goes to the other (opposite) side of the hills, plateaus, etc. it is left with little water vapour. Therefore, the rainfall is much less on the opposite side. This type of rain is called relief rain as it is caused mainly due to the relief of the land. The opposite side of the hill where the rainfall is much less is called the rain-
shadow area. The Deccan plateau is an example of a rain-shadow region in India.

3. Cyclonic rain: When a cyclone occurs, the wind from the surrounding areas blows rapidly to the centre of low pressure and on reaching there becomes hot and rises up. Then the water vapour in the air condenses and there is heavy rain. This heavy rain is often accompanied by thunder and storm.

Question 21. Specify the factors responsible for thermal variation in the atmosphere.
Answer: Climatic factors (such as latitude, altitude, insolation, distance from the sea, prevailing winds, ocean currents, the slope of the land, the position of the mountains, natural vegetation, cloudiness, etc.) are the main causes of variation of temperature in the atmosphere.

1. Latitude: On the equator (0°) the sun’s rays are vertical, more or less, throughout the year and as we go towards poles (90°N and 90°S) these rays are slanting. Vertical rays are hotter. The smaller area is heated by the vertical rays and they are to travel a shorter distance. On the contrary, the slanting rays travel a longer distance and warm up a larger area. Hence, temperature decreases from the equator to the poles.

2. Altitude: For every 100 metres of height from sea level, there is a decrease of 0.6°C in temperature.

The reasons for this decrease are:
(1)Atmosphere is primarily heated by radiation and conduction of the earth’s surface, thus the lower layers of the atmosphere are warmer than the higher ones. Siliguri is situated in the plain region and is, therefore, warmer than Darjeeling situated at higher altitudes,
(2) the upper atmosphere is thinner and cannot absorb much temperature.

3. Insolation:
Heat waves from the sun radiate at he rate of 3,00,000 km per second and: only 1/2200 C2: the millionth part of solar radiation reaches the earth’s Cc) surface. The rest is reflected by the earth’s surface and atmosphere. This is called ‘Albedo’. 14% of that heat is absorbed by the earth’s surface and its atmosphere.

This is the sole source of earth’s heat energy. Due to the varying inclination of the rays of the sun and varying lengths of the day and night, etc., insolation varies considerably on parts of the earth’s surface.

4. Distance from the sea: Coastal areas enjoy a mode place or area situated at a distance from the sea. Calcutta enjoys a moderate temperature compared to Patna.

5. Prevailing winds: Winds coming from the sea lower the temperature in the summer season and raise the temperature in winter. Due to the westerlies (coming from the sea), there is a moderate temperature in NW Europe, whereas cold winds from Western India bring cold waves in the Northern plain.

6. Ocean currents: Warm ocean currents raise the temperature of the coastal areas whereas cold ocean currents lower the temperature. Due to the warm Gulf stream, orth-western European coast is warmer and never freezes whereas the North-eastern Canadian coast is frozen most of the year due to the cold Labrador currents.

7. Slope of the land: In the Northern hemisphere, south-facing slopes are warmer than the north-facing slopes, while the conditions in the Southern hemisphere are reversed. The southern slopes of the Himalayas are warmer than that of the Northern slopes.

8. Position of mountains: Mountains check the cold wind and at the same time check the warm winds laden with water vapour resulting in rainfall. The cold winds from Central Asia are checked so much so that India is protected from severe cold and at the same time the Himalayas obstruct the moisture-laden winds that give rainfall to the Northern plain.

Geography Class 10 West Bengal Board

9. Natural Vegetation: Air is cooled above the forests, and thereby temperature is low over the land.
10. Soils: Sandy soils are cooled and heated quickly (as in Rajasthan), whereas clayey soils are cooled and heated slowly.

11. Cloudiness: Sun’s rays are obstructed by clouds to reach the earth’s surface during daytime and at night radiation is checked, as that cloudy nights are warmer and cloudy days are cooler.

Question 22. Name the different layers of the atmosphere on the basis of temperature and describe each of them.
Answer:
Layers of the atmosphere: According to recent scientific research, the atmosphere contains the following layers:

1. Troposphere: This is the lowest layer of the atmosphere. It is up to a height of 16 km on the equator and at the poles, the height is 8 km. The main feature. of this layer is that temperature decreases in relation to the height (for every 100-metre increase in height the decrease in temperature is 0.6°C) 75% of all the water vapour, cloud, and dust particles are found in this layer. That is why this layer is called the weather-making layer.

2. Stratosphere: This layer is found up to a height of 50 km above the Troposphere. There is no formation of clouds in this layer and thus there is no weather. There does not exist any danger of the storm. That is why this layer is ideal for aircraft.

3. Ozonosphere: Ozone is produced by the action of solar radiation. The maximum heating occurs near the top of the ozone layer where air temperatures are similar to those near. the earth’s land-sea surface.

4. Mesosphere: Air temperature decreases with height. The decrease in temperature becomes as low as 80°C at an altitude of about 80 km. Sometimes- 120°C is recorded.

5. ionosphere: This is also known as Thermosphere. It is a zone of ion gas, electrons and atoms. The temperature increases very rapidly. The air in this layer contains clear charges and this accesses pe waves so that radiocommunication becomes possible.

It also absorbs the deadly ultraviolet rays of the sun. Thus, it is beneficial to human beings and other living creatures. The northern lights or Aurora Borealis and southern lights or Aurora Australis occur in this zone.

Question 23. Account for the shifting of pressure belts.
Answer:
Shifting of Pressure Belts: The pressure belts shift with the apparent movement of the sun. Summer solstice (on 21st June) the sun shines vertically over the Tropic of Cancer in the Northern hemisphere. All the pressure belts move about 5° to 10° North of their average position.

At winter solstice(on 22nd December) the sun is overhead on 21st March at the Tropic of Capricorn. Consequently, & all the pressure belts move 5° to 10° South 2istJune 23 Spet. 22nd Dec of their average location. This seasonal movement of pressure belts is known as the Shifting of Pressure Belts.

With the shifting of the pressure belts, the wind belts also shift their position which causes the change of their direction and velocity of flow.

As the pressure belts shift with the seasons, the belts of precipitation associated with them also change their positions. The regions between 30° and 40° North and South have Trade winds during their summer and they are dry.

But in winter, with the shifting of the pressure belts, these regions come under the influence of the Westerlies which bring rain. Winter rain is the main characteristic feature of the Mediterranean climate.

School Geography Class 10 WBBSE

Question 24. Write notes on Mountain and valley winds.
Answer:
Mountain and valley winds: These are local slope winds. These are periodic winds which blow along the valley slopes. In mountainous areas, the valley winds blow up the slope during the day and the mountain winds blow down the slope by night. These winds are caused due to differential heating and cooling of valley and hills tops.

1. Mountain winds: In hilly aréas, cold and dense air blowing down valley slopes during the night are called mountain winds. During the night the winds at the hill become cold and dense due to rapid radiation. This cold air, under the influence of gravity, descends down the valley slopes. It is known as air drainage.

These descending winds are called mountain winds or gravity winds or Katabatic winds. Due to these, the front occurs in the lower parts of the valleys. Therefore, citrus orchards in California and coffee fazendas in Brazil are grown on hill slopes.

2. Valley winds: In hilly areas, the warm winds ascending up the valley slopes during the day are called valley winds. During the day. hilltops get heated due to insolation and develop low pressure. The warm air of the valley bottoms blows up the slopes to take its place. These ascending winds are known as valley winds or Anabatic winds. As the winds rise, these are condensed and give heavy rain. These winds tend to moderate the temperature.

Geography Class 10 West Bengal Board India – Drainage Of India True Or False Type:

Question 1. Logtak is the largest lagoon of India.
Answer: False

Question 2. The confluence of the Alakananda and Bhagirathi rivers is at Devprayag.
Answer: True

Question 3. Malta is a tidal river.
Answer: True

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 4. Bhagirathi is the distributary of the Ganga.
Answer: True

Question 5. Rupnarayan is the joint flow of Dwarakeswar and Silai.
Answer: True

Question 6. Majuli is the largest river island.
Answer: True

Geography Class 10 West Bengal Board

Question 7. Mahanadi is the main river of Orissa.
Answer: True

Question 8. Luni is the only inland drainage of India.
Answer: True

Question 9. The rivers of northern India are fed by rainwater and ice-melting water.
Answer: True

Question 10. River Indus rises from Manasarobar.
Answer: False

Question 11. The Brahmaputra flows into the Arabian Sea.
Answer: False

Question 12. Sutlej is the tributary of river Indus.
Answer: True

Question 13. Gangotri glacier is the source of the river Ganga.
Answer: True

Question 14. River Damodar was called the ‘Sorrow of West Bengal’.
Answer: True

Question 15. Godavari is called the Ganga of South India.
Answer: True

Question 16. The Dibang and the Luhitare two tributaries of the Brahmaputra.
Answer: True

Question 17. The Luni flows in Rajasthan and drains towards southwest to meet the Rann of Kachchh.
Answer: True

Question 18. The Brahmaputra is the largest tributary of the Ganga.
Answer: False

Question 19. The river Yamuna rises from the Gangotri glacier.
Answer: False

Question 20. The Mahanadi is the largest river of south India.
Answer: False

Question 21. Mahanadi, Godavari and Krishna are the west-flowing rivers of India.
Answer: False

Question 22. Yog falls is on the Sarasvati river.
Answer: True

Question 23. Mahi rises in the Satpura Range.
Answer: False

Geography Class 10 West Bengal Board

Question 24. Ganga rises in the Yamunotri glacier.
Answer: False

Question 25. Vembanad Lagoon is in the East coast.
Answer: False

Question 26. Chilka is the largest lagoon of India.
Answer: True

Question 27. One lagoon in the Coromandel Coast is Pulicat.
Answer: True

Question 28. Tista rises in the Zemu Glacier.
Answer: True

Question 29. Manas is the longest river of Deccan.
Answer: False

Question 30. Kaveri is the longest river of Deccan.
Answer: False

Question 31. Sarasvati is a west-flowing river.
Answer: True

Question 32. Hirakud is the longest dam in India.
Answer: True

Question 33. Bhakra is the highest dam in India.
Answer: True

Question 34. Gandhi Sagar is on Chambal River.
Answer: True

Question 35. Idukki Barrage is in Kerala.
Answer: True

Question 36. Pong Dam is on Ravi.
Answer: False

Question 37. The rivers of south India are favourable for hydroelectric power production.
Answer: True

Question 38. The south Indian rivers are more navigable than the north Indian rivers.
Answer: False

Question 39. The north Indian rivers have long courses, many tributaries and distributaries.
Answer: True

Question 40. The Godavari-Krishna delta is the largest delta in India.
Answer: False

Question 41. The river Ganges has her source near Mansarovar.
Answer: False

Question 42. The largest river basin of India is the Brahmaputra basin.
Answer: False

Question 43. The Luni drains into the Arabian sea.
Answer: False

Question 44. The river Sharavati is noted for being the largest waterfall in India.
Answer: True

Question 45. Brahmaputra rises from the Chemaung Dung Glacier.
Answer: True

Class 10 Geography West Bengal Board India – Drainage Of India Fill In The Blanks Type:

Question 1. The Brahmaputra is known as ______ in Arunachal Pradesh.
Answer: Dibang.

Question 2. Mayurakshi rises in the ______ hills.
Answer: Trikut.

Geography Class 10 West Bengal Board

Question 3. Luni rises in the ______.
Answer: Annasagar lake.

Question 4. Paglajhora falls is on _____.
Answer: Mahananda river.

Question 5. Yog is the highest _____.
Answer: Waterfall in India.

Question 6. Sabarmati rises in the _____.
Answer: Aravalli Range.

Question 7. Tapti has its source in the _____.
Answer: Mohave Hill.

Question 8. Tungabhadra is the tributary of ______.
Answer: Krishna river.

Question 9. Hemabati is the tributary of ______.
Answer: Kaveri river.

Question 10. Piranha is the tributary of _______.
Ans. Godavari river.

Question 11. ______ is the longest river of India
Answer: Ganga.

Question 12. _____ is the main tributary of Ganga.
Answer: Yamuna.

Question 13. Godavari has its source in the ______ hills.
Answer: Tryambak.

Question 14. Kaveri has its source in the _____ hills.
Answer: Brahmagiri.

Question 15. Yog fall is situated on ______river.
Answer: Sarasvati.

Question 16. Sivsamudram has its source in the _____ Glacier.
Answer: Kaveri.

Geography Class 10 West Bengal Board

Question 17. Tista has it source in the ______.
Answer: Zemu Glacier.

Question 18. The river Ganga receives Mandakini at ______.
Answer: Rudraprayag.

Question 19. The Yamuna river rises from the ______ Glacier.
Answer: Yamunotri.

Question 20. The Dihang acquires the name Brahmaputra after its union with Dibang and ______
Answer: Lohit.

Question 21. The Kaveri drains into the ______.
Answer: Bay of Bengal.

Class 10 Geography WBBSE India – Drainage Of India Very Short Answer Type:

Question 1. In which State of India, the lower course of river Ganga lie?
Answer: West Bengal.

Question 2. What is the local name of the lagoons in Kerala coast?
Answer: Kayal.

Question 3. Name the highest waterfall of India.
Answer: Jog/Girisppa.

Question 4. What is the name of the river Brahmaputra in Arunachal Pradesh?
Answer: The name of Brahmaputra in Arunachal Pradesh is Dihang.

Question 5. Name the largest saline lake in India.
Answer: Sambar in Rajasthan is the largest saline lake in India.

Question 6. Name the largest fresh water lake in India.
Answer: Wular taken Kashmir is the largest freshwater lake in India.

Question 7. Which is the largest lagoon in India?
Answer: Chilika is the largest lagoon in India.

Geography Class 10 West Bengal Board

Question 8. Name the source of the river Ganga.
Answer: Gangotri glacier.

Question 9. Name the source of the river Yamuna.
Answer: Yamunotri glacier.

Question 10. Name the source of the river Tista.
Answer: Zemu glacier.

Question 11. Name one tributary of Brahmaputra river.
Answer: Manas.

Question 12. Name the world’s largest river island.
Answer: Majuli in Brahmaputra.

Question 13. On which river Sivasamudram falls is situated?
Answer: Kavery.

Question 14. On which river Yog falls is situated?
Answer: On Saravati river.

Question 15. On which river Marble falls is situated?
Answer: Narmada.

Question 16. On which river Paglajhora falls is situated?
Answer: Mahananda.

Question 17. On which river Hudroo falls is situated?
Answer: Subarnarekha.

Question 18. Name the major types of Indian rivers.
Answer:
1. The Himalayan rivers,
2. Rivers of Central India,
3. Coastal rivers,
5. Inland river.

Question 19. Name the principal watersheds of India.
Answer:
1. The Karakoram, the Tibet Himalaya and the Himadri Himalaya,
2. The Vindhya Range in Central India is streng the end by the Satpura- Maikal range and
3. The Sahyadri in the west.

Class 10 Geography West Bengal Board

Question 20. Name the largest river basin of India.
Answer: TheGanga Basin.

Question 21. Name three regions in India which are well-known for under-ground streams.
Answer:
1. Gaya region,
2. Cherrapunji region,
3. Dehra Dun region.

Question 22. Name the regions which well-known for springs.
Answer:
1. The Kumayun Region,
2. The genetic hills and uplands of south Bihar,
3. The western foot of the Sahyadri in the Konkan Region.

Question 23. Mention the three drainage systems of India.
Answer:
1. Central highland towards Ganga Basin,
2. Towards the Arabian Sea and
3. Towards the Bay of Bengal.

Question 24. Name the source of the Indus.
Answer: Sin-Ka-bab about 100 km north of Manas Sarowar.

Question 25. Name the source of the river Brahmaputra.
Answer: Chemaung Dung Glacier.

Question 26. Name the source of the river Krishna.
Answer: Mahabaleswar Hills (Western Ghats).

Question 27. Name the source of the river Godavari.
Answer: Trayambak Hill near Nasik.

Question 28. Name the source of the river Mahanadi.
Answer: Shiara Range of Chhattisgarh highland.

Question 29. Name the source of the river Kavery.
Answer: Brahmagiri Hill (Western Ghats).

Question 30. Name the source of the river Narmada.
Answer: Amarkantak peak of Maikal Range.

Class 10 Geography West Bengal Board

Question 31. Name the source of the river Tapti.
Answer: Betal of the Mahadeo hills.

Question 32. Name the source of the river Luni.
Answer: Annasagar Lake.

Question 33. Name the source of the river Damodar.
Answer: Khamarpath Hills.

Question 34. Name the source of the river Mayurakshi.
Answer: Trikut Hills.

Question 35. Name the source of the river Sabarmati.
Answer: Aravalli Range.

Question 36. Which lakes are known as twin lakes?
Answer: Kuleru and Suleru (Andhra Pradesh).

Question 37. Which is the largest lagoon in India?
Answer: Chitika.

Question 38. Name one lagoon in the Coromandel Coast.
Answer: Pulicat.

Question 39. Name one lagoon in the Malabar Coast.
Answer: Kayal.

Question 40. Name the source of the river Ganga (2510 km).
Answer: Gangotri Glacier.

Question 41. Name the largest river island in the world.
Answer: Majuli island.

Question 42. Name the source of the river Subarnarekha (477 km).
Answer: Chhotanagpur Plateau.

Question 43. Name the source of the river Brahmani (800 km).
Answer: Chhotanagpur Plateau.

Class 10 Geography West Bengal Board

Question 44. Name the tributaries of the Godavari.
Answer: Pranhita, Indrawati, Sabari, Pengonga, Wardha, Manjira.

Question 45. Name the tributaries of the Krishna.
Answer: Bhima, Koyna, Ghatprabha, Malprabha, Tunga and Bhadra.

Question 46. Name the tributaries of the Krishna.
Answer: Hemabati, Simsa, Bhabani.

Question 47. Name the highest waterfall of India.
Answer: Yog falls.

Question 48. Name the waterfall on the river Kaveri.
Answer: Sivsamudram.

Question 49. Name the tributaries of Mahanadi river.
Answer: Bramhani, Baitarini.

Question 50. Name the waterfall on the river Narmada.
Answer: Marble falls or Dhaunadhara Waterfalls.

Question 51. Name one tributary of river Tapi.
Answer: Puma.

Question 52. Name the tributaries of the river Ganga.
Answer: Yamuna, Son, Gomati, Ramganga, Ghagra, Gandak, Kaligandak, Kosi.

Question 53. Name the tributaries of Brahmaputra.
Answer: Subarnasiri, Manas, Sankosh, Lohit, Dhanasiri.

Question 54. Name the tributaries of the river Indus.
Answer: Sutlej, Chenab, Ravi, Beas and Jhelum.

Question 55. Name the joint flow of the river Alkananda and Bhagirathi.
Answer: Ganga.

Question 56. Name the waterfalls on Mahananda.
Answer: Paglajhora falls.

Question 57. Name two west-flowing rivers of India.
Answer: NarmadaandTapi.

Question 58. Name the longest river of the Deccan.
Answer: Godavari.

Question 59. Name the waterfalls on the river Subarnarekha.
Answer: Hudroo and Johna.

Question 60. Name the waterfalls on the river Gomati.
Answer: Dombur falls.

Question 61. Name the waterfalls of the state of Meghalaya.
Answer: Bidan, Bishop and Elephanta.

Class 10 Geography West Bengal Board

Question 62. What is the name of the river Brahmaputra in the Tibetan Plateau?
Answer: Tsangpo.

Question 63. What is the name of the river Brahmaputra in Arunachal Pradesh?
Answer: Dihang.

Question 64. Name the joint flow of Dihang, Dibang and Lahit.
Answer: Brahmaputra.

Question 65. Name the river which originates near Mansarovar lake and flows eastwards for about half of its course before entering India.
Answer: The Brahmaputra.

Question 66. Name the river which originates in the Himalayas and flows through four Indian states before forming the largest delta of the world.
Answer: The Ganga.

Question 67. Name the river which was probably a tributary of the Indus in the Pliestocene age but is now a tributary of the Ganga.
Answer: The Yamuna.

Question 68. Name the major river originating from Mansarovar region, flowing towards the west and forming a delta.
Answer: The Indus.

Question 69. Name the longest river of the Peninsular India.
Answer: The Godavari.

Question 70. Name the river on which Hirakud Dam is located.
Answer: The Mahanadi.

Question 71. Name an important river of the Great Indian Desert.
Answer: Luni.

Question 72. Name the river on which the highest gravity dam in the world has been constructed.
Answer: The Satluj where Bhakra Dam has been constructed.

Question 73. Name the major originating from a spring near Mahabaleshwar.
Answer: The Krishna.

Question 74. Name the river of south India which receives rain water both in summer and winter.
Answer: Kaveri.

Question 75. Name the tributary of Yamuna which is notorious for its ravines.
Answer: The Chambal.

Question 76. Name the river on which the Damodar Valley Corporation is located.
Answer: The Damodar.

Question 77. Name the state with the largest network of irrigation canals.
Answer: Uttar Pradesh.

Question 78. Name the state with the largest area under well irrigation.
Answer: Rajasthan.

Question 79. Name the state with the largest area under tube-well irrigation.
Answer: Uttar Pradesh.

Question 80. What is the name of the watershed management project undertaken by the Central Government of India?
Answer: Haryali.

Class 10 Geography West Bengal Board

Question 81. Which river is known as ‘red river’?
Answer: Brahmaputra.

Question 82. Name an ideal river.
Answer: Ganga.

Question 83. Which river is called the ‘Ganga of the South’?
Answer: River Godavari is called the ‘Ganga of the South’.

Question 84. Which river is formed by joining Bhagirathi & Alakananda?
Answer: Bhagirathi and Alakananda join to form river Ganga.

WBBSE Class 10 Geography Solutions India – Drainage Of India 2 Marks Questions And Answers:

Question 1. Name two watershed regions of India.
Answer:
1. The Karakoram, the Tibet Himalayas and the Himadri in the north,
2. The Vindhya range in Central India was strengthened by the Satpura-Maikal.

Question 2. Mention two purposes of rainwater harvesting.
Answer: Two purposes of rainwater harvesting are:
1. It provides an independent water supply during regional water restrictions or droughts.
2. It can mitigate flooding of low lands.

Question 3. Describe the course of the river Indus.
Answer: The river Indus originates from the springs of Sengee Khabal near lake Manas Sarovar and enters in India through Ladakh. It cuts through the Himalayas in a deep gorge near Nanga Parbat and it leaves Kashmir to enter Pakistan. It finally drains into the Arabian sea. The mighty five tributaries on the left bank of the Indus are – the Beas (Bipasha), the Jhelum (Vitasta), the Satluj (Satadru), the Ravi (Irrabati), Chenab (Chandrabhaga).

Question 4. Mention the source and mouth of the river Ganga.
Answer: The Ganga river rises from the ice cave of Gomukh of Gangotri Glacier on Kumaon Himalaya and travels down in the form of a headstream named Bhagirathi and continues flowing southwards and finally drains.into the Bay of Bengal.

Question 5. Mention the source of the Ganga and describe its course.
Answer: Bhagirathi, the headstream of Ganga rises from Gomukh, an ice cave of the Gangotri glacier on the Kumaon Himalaya. Flowing southwards, Ganga descends on the plain at Haridwar.

Question 6. Name two left bank tributaries of the Ganga.
Answer: Kosi and Gandak.

Class 10 Geography West Bengal Board

Question 7. Mention the names of two principal tributaries of the Godavari river.
Answer: Pranhita and Indravati.

Question 8. Name two right bank tributaries of the Ganga.
Answer: Yamuna and Sone.

Question 9. Name the major rivers of India which do not have a delta.
Answer: Narmada & Tapti rivers do not have a delta.

Question 10. Name two salt lakes of Rajasthan.
Answer: Sambhar and Pushkar are two salt lakes of Rajasthan.

Question 11. Name the origin of river Narmada.
Answer: The origin of river Narmada is the Amarkantak peak of the Maikal range.

Question 12. Name a river of India flowing through a rift valley.
Answer: The Narmada flows through a rift valley between the Vindhya and Satpura ranges.

Question 13. Name one inland river of India and mention its course of flow.
Answer: River Luni is an inland river of India. Coming out of the Annasagar lake it flows towards the south-west and falls into the Rann of Kachchh.

Question 14. There is little irrigation in the Himalayan region in spite of a large number of big rivers. Why?
Answer: There is little agricultural land due to rugged topography and the rivers are swift-flowing.

Question 15. Why is the conservation of water necessary?
Answer: Conservation of water is of utmost importance in India because of
1. Shortage of water supply,
2. Increasing demand for water due to the growth of population,
3. Uneven distribution of water in the country and
4. widespread water pollution.

Class 10 Geography WBBSE

Question 16. Name some important multi-purpose river valley projects in India.
Answer:
Some Important River Valley Projects:
1. The Damodar River Valley Project (West Bengal and Jharkhand) on river Damodar.
2. The Bhakra-Nangal Project (Punjab and Haryana) on river Sutlej,
3. The Mayurakshi Project (West Bengal and Jharkhand) on the river, Mayurakshi.
4. The Hirakund Project (Orissa) on river Mahanadi.
5. Tungabhadra Project (Andhra Pradesh) on Tungabhadra river,
6. Kakrapara Project (Gujarat) on riverTapti.

Question 17. Distinguish between barrage and multi-purpose dam.
Answer:
1. Dams are built up on the upper course of a river where mountainous river valleys can be dammed easily on hard rocky terrain. On the other hand, barrages are constructed on the lower course of a river on plains.
2. MuJtipurpose dams are built to provide a series of facilities, such as flood control, irrigation, hydro-electric power generation, pisciculture, afforestation, soil conservation, road construction and so on.
Example: Maithan Dam.
On the other hand, barrages are built to provide irrigation water and flood control only.
Example: Durgapur Barrage.

Question 18. What is a Persian wheel’?
Answer: Persian wheel is a method of lifting water from wells. By the Persian wheel method, a wheel with many buckets around a circumference is pulled by a rope by an animal in such a manner that buckets of water rise from the well to the surface one after another.

Question 19. What are the problems that arise from irrigation?
Answer: The problems created by irrigation in Indian agriculture are:
1. Defective crop selection: By irrigation, agricultural land avails water throughout the year. So when the land was unirrigated a single crop was raised, but by irrigation, those lands produce multiple crops; some of these crops may destroy the natural fertility of the soil.
2. Problems of water logging: Over irrigation causes water-logging and damages Kharif crops.
3. Problems of salinity: Excessive use of groundwater causes the salts deep beneath the ground to reach to the surface.

Question 20. Describe any three important advantages of multipurpose projects.
Answer: The advantages of Multipurpose River Valley Projects may be summarized as follows:
1. Dams built on a river and its tributaries help in impounding huge amount of rain water. These help in controlling floods and protecting soil erosion.
2. The impounded water can be used for irrigation during the.dry season.
3. The stored water can also be used for generating hydroelectricity-a renewable and non-polluting source of energy.

Geography Class 10 Solutions WBBSE India – Drainage Of India 3 Marks Questions And Answers:

Question 1. State the differences between tributaries and distributaries.
Answer:
Tributaries:
1. It is a river which flows into a large river.
2. It increases the volume of the main river.
3. It is found in three stages of the river- upper, middle and lower.
4. Tributaries are fast-flowing. 5. Yamuna is the tributary of the Ganga.

Distributaries:
1. It is a river which flows away from the main river.
2. It decreases the volume of the main river.
3. It only provides a network of transport in the lower course.
4. Distributaries are slow-flowing.
5. Hooghly is the distributaries of Ganga.

Class 10 Geography WBBSE

Question 2. Why are floods frequent in the northern rivers?
Answer: The northern rivers are long-flowing and are perennial. They are rain-fed as well as snow-fed. During the rainy season due to heavy rainfall, the rivers overflow their banks causing floods. In their course of flow, they are depositing silt and thereby making the river shallow. During the rainy season, in case of increase of waterflood occurs.

Question 3. Why are floods frequent in the Brahmaputra valley?
Answer:
1. Brahmaputra valley is drained by the river Brahmaputra and its tributaries. The region is prone to earthquakes, so the river is changing its course very often, causing floods,
2. Sometimes river beds are raised because of earthquakes causing floods,
3. The river has taken a zig-zag course. So during rainy seasons, its banks are over-flooded with rainwater,
4. Deposition of silt at the river bed, making the river shallow and causing floods.

Question 4. Name the famous lakes and lagoons of India.
Answer: Walter, Dal and Nagin lakes in Jammu & Kashmir; Changu lake in Sikkim, Loktak lake in Manipur, Lake Nainital & Lake Bhimtal in U.P., lake Sampur in Rajasthan, lake Nal in Gujarat, lake Topchachi in Bihar, lagoon Chilika in Orissa, lagoon Pulicat in Tamil Nadu, lagoon Vembanad in Kerala.

Question 5. What is the source of the Indus? What is the nature of its valley through Kashmir?
Answer: The Indus rises from the springs of Sin Khabab about 100 km North of Manas Sarowar in Tibet. It travels 250 km in Tibet before entering Kashmir. Intra versus Kashmir diagonally for a distance of 650 km remaining confined within a narrow gorge, 10 km wide on average. Before entering Pakistan, the Indus takes a sharp southerly turn, cutting the Ladakh range through the world’s deepest gorge, 5,200 m deep near Bunji.

Class 10 Geography WBBSE

Question 6. Name the principal rivers of the Central Highlands.
Answer:
1. The Banas and the Chambal in the East Rajasthan upland and Madhya Bharat Pathar,
2. The Betwa, Parbati, Newaj and Mahi on the Malwa Plateau,
3. The Son and its tributaries, viz. Banas, Rihand, Kanhar and North Kosi on the Vindhyan Scarplands, and
4. The Narmada.

Question 7. Discuss the tributaries of both sides of the river Ganga.
Answer: The Major Tributaries of Ganga:
1. The Yamuna (1,375 km) is the largest tributary of the Ganga. The Yamuna receives a number of tributaries on its right bank – the Chambal, the Sindh, the Betwa, and the Ken.
2. The Ramganga (690 km) pours its water at the left bank of the Ganga near Kanauj and
3. The Sarda at the right bank of the Gharghara near Bahramghat.
4. The Gharghara [1,080 km in India] becomes one with the Ganga near Chapra.
5. The Gandak [610 km] empties her water at the bank of the Ganga.
6. The Kosi [730 km in India] rises from the Tibet plateau and flows down into the Ganga at its left bank at Karla.

Question 8. Many Ox-bow lakes have been formed in the valley of the river Brahmaputra. Why?
Answer: Brahmaputra is a long river. Hence it takes huge sediments with it. In the Assam valley, the surface is very plain and, therefore, the river flows very slowly here. It doesn’t have the capacity to carry a huge amount of alluvium. When any obstruction comes in its way it turns and hence makes lots of curves in its path. Sometimes that curve separates from the main channel and looks like a horseshoe. Hence it is called horse-shoe lake or Ox-bow lake.

Class 10 Geography WBBSE

Question 9. What are antecedent and consequent rivers?
Answer: If an earth movement of upliftment or tilting takes place in the way of a river, the river may or may not change its direction of flow. If an upliftment of tilting may be on such a scale that the pre-existing river is able to maintain its course or direction, The river starts down-cutting at the same rate of upliftment. Thus, rivers like Indus, Satluj & Brahmaputra form deep gorges in the Himalayan region. Consequent rivers follow the weak zones of the mountains, like faults, and axial planes to cut across the mountains when they started flowing after the mountain were formed.

Question 10. Describe the course of the river Ganga.
Answer:
Ganga: The source of the Ganga is the ‘Gangotri’ glacier situated in the district of Garhwal of Uttaranchal. Here it is called Bhagirathi. The Alaknanda river originates from the Badrinath glacier. These two rivers join at Devaprayag situated in the North of Haridwar. From here it is known as the Ganga river. After Haridwar, it enters the plain near Rishikesh. From here the river flows slowly towards East. At Prayag (Allahabad) Yamuna river meets the Ganga. Further eastward, Gomati, Ghagra, Gandak and Kosi from the North-West and Son river (originating from Maikal mountains) from the South meet the Ganga.

After this, Mayurakshi, Ajoy, Damodar, Rupnarayan, etc. meet the Bhagirathi (branch river of the Ganga). Another branch of this river is Padma which meets the Brahmaputra. Before falling in the Bay of Bengal, the Ganga meets the Brahmaputra and makes the largest delta (79,700 sq. km.). Before falling into the Bay, the Ganga is divided into many branches, namely Madhumati, Ichhamati, Hooghly and Bhagirathi. On the right bank of the Hooghly, Howrah is situated and on the left bank, Kolkata. On the banks of the Ganga Haridwar, Varanasi, and Prayag are pilgrimage centres whereas Kanpur, Patna, etc. are the trade centres.

Question 11. Describe the course of the river Brahmaputra.
Answer:
River Brahmaputra: The river Brahmaputra is 2900 km long. It rises in Tibet from the Chemaung-Dung glacier near Mansarovar lake. It flows towards the East for 1200 km parallel to the Himalayas and is known as the Tsangpo river. After this, the river makes a sharp bend towards the South and enters India through a deep narrow gorge in the East of Namcha Barwa in Arunachal Pradesh and here it is known as the Dihang river. Here the Dihang river meets the Dibang and Lohit rivers and the combined flow is known as the Brahmaputra. In Assam valley, the river flows westward from Sadiya to Dhubri.

Subansiri, Manas, Bharel, Kopoli, Dhausiri and Buridihangarethe important tributaries of the river. After Dhubri it enters Bangladesh and is known there as the “Jamuna” river. Again it joins the Padma and forms a great delta that falls in the Bay of Bengal. Due to the gentle slope, the river is joined by many small tributaries which bring a lot of sediments and sand that form small islands. Among these Majuli island (the largest river island in the world) covers an area of 1260 sq. km in Assam. The deposit of silt on the river bed is so much that it becomes shallow and it cannot hold excess water in the rainy season resulting in floods every year. Guwahati, Tejpur, Dhubri, Dibrugarh are the important towns on the river.

Question 12. Why is Ganga called an ideal river?
Answer:
Ganga is an ideal river: The Ganga is a complete river; it has three stages in its course of flow. It has a number of tributaries like Yamuna, Ramganga, Ghaghara, etc. It has also distributaries like Bhagirathi-Hooghly. The Ganga is the longest river of India and has the largest river basin in India covering an area of 8,38,200 sq. km. The Ganga is a perennial river as the water is available around the year. The river has formed one of the most fertile floodplains of the world. The river has made many natural waterways of India. It is navigable up to Haridwar. It has created flood plains, ox-bow lakes, deltas, levees, etc. which are the features of an ideal river. the Ganga is the most sacred river of India. The fertile river basin is the granary of India. All these features make it an ideal river of India.

Class 10 Geography WBBSE

Question 13. Why do the west-flowing rivers of India not have deltas?
Answer:
1. Most of the west-flowing rivers are small in size, so they carry a small amount of silt,
2. Though Narmada & Tapti are relatively small but the velocity of these rivers is high, so deposition of silt at the mouth is not possible,
3. Arabian sea is more violent than the Bay of Bengal, so massive action clears the mouth of rivers,
4. The west-flowing rivers have a little number of tributaries which add silt to the main river.

Question 14. Most of the rivers of the Deccan are east-flowing Why?
Answer: Most of the rivers of the Deccan are east-flowing because of the following reasons:
The south Indian or Deccan rivers have their sources (most of them) in the Western Ghats which is a continuous range. So the rivers are not getting easy access to the Arabian Sea. Therefore, they flow towards the east. The slope of the Deccan plateau is from west to east.

In ancient times lava coming out of the earth was first deposited in the west and then slowly spread over the east — thereby it has created a gentle slope of the plateau from west to east. It is the nature of water to flow according to the slope of the land. As the land slopes from west to east, the rivers flow west to east. The Eastern Ghats is a broken range and the rivers are getting easy access to the Bay of Bengal. But Narmada and Tapi are falling into the Arabian Sea. They are west-flowing rivers.

Question 15. Narmada and Tapi have no deltas at their mouth Why?
Answer:
Narmada and Tapi have no delta at their mouths because of the following reasons:
1. For the creation of a delta, certain conditions must be fulfilled. The river must have all three stages in its course of flow and speed must be slackened in the lower stage.
2. The rivers must not flow over hard surfaces and must carry a huge amount of silts.
3. The mouths of the river must be wide enough to have deltas.
4. There must not be any lake in its course of flow.
5. At the mouth there must not be any current which can wash the silt deposited there.

Narmada and Tapi have only two stages in their course of flow—the upper and the lower courses. The rivers are flowing over hard surfaces and are not carrying a huge amount of silt. Their mouths are not wide enough to have deltas and at the mouth, there is under current which washes away the deposited silt. That is why they have no delta at their mouths.

Question 16. Which river is called the sorrow of Bengal and why?
Answer: Damodar is called the sorrow of Bengal as it creates floods each and every year. River Damodar rises from the Khamarpath Hills of the Chhotanagpur Plateau and flows through Jharkhand. That is why it was used to be called the ‘Sorrow of Bengal’.

But at present dams have been constructed on the river and floods are controlled. With the help of irrigation water, agriculture is flourished and industrial development took place because of hydei and thermal power produced by the hydel and thermal projects. Now the region is no longer a flood-stricken area.

Class 10 Geography Book West Bengal Board

Question 18. Where are the principal ground-water basins of India?
Answer:
The three major ground-water basins of India are:
1. The Ganga basin,
2. The Punjab alluvial basin stretching from Ludhiana to Amritsar, and
3. The Western basin covers portions of Rajasthan and Gujarat. Of these, the Ganga basin is the largest. There are more than 5,000 electrified deep tubewells in U.P. and a good number in Bihar also.

Question 19. Which regions are well-known for springs?
Answer:
Springs in India are found mainly in 3 regions:
1. In Kumaun, U.P., around the Nanda Devi and the Kamet group of peaks in the Himadri or Great Himalayas,
2. in the low gneissic hills and uplands of South Bihar,
3. In the western foot of the Sahyadri in the Konkan region.

Question 20. Why do the rivers on the western coast have no deltas, even though they transport a lot of sediment with them?
Answer: Over 600 small streams originate from the western Ghats and meet the Arabian Sea. They also transport a lot of sediment with them but are not able to deposit this sediment at the coast because they are very swift due to the steep slope of the Ghats and narrow coastal plain. Therefore, they do not form deltas. Narmada and Tapi are two big rivers but they flow in rift valleys. As such they are also incapable of forming deltas and estuaries.

Question 21. What is a gorge? Give two examples from north India.
Answer:
Gorge: The rivers are in their youthful stage in the mountain area and form very narrow and deep valleys due to down-cutting. This is known as the gorge. Its banks are almost vertical. The Indus, the Satluj and the Brahmaputra (Dihang) have formed gorges in the Himalayas.

Question 22. What is a Delta? Give four examples from India.
Answer: The river deposits its sediment when it enters the sea, thus forming a triangular-shaped feature which is known as a delta. The river divides itself into several channels. known as distributaries. The delta is very fertile and is most suited for agriculture. The Ganga-Brahmaputra, the Mahanadi, the Godavari-Krishna and the Cauvery are the important deltas in the Indian sub-continent.

Question 23. Which river is called the ‘Dakshin Ganga’ and why?
Answer: The river Godavarjjs is popularly known as Dakshin Ganga. It is the largest river of South India. It forms the largest basin in the peninsular part of India, as the Ganga in the northern plains of India (It is, however, much smaller than the Ganga basin). Thus for its vast basin area, great length and cultural heritage, the Godavari can rightly be compared with the Ganga of northern India and hence the name.

Question 24. What does rainwater harvesting include?
Answer: Rainwater harvesting means collecting and storing rainwater, which includes activities aimed at:
1. Harvesting surface water and groundwater,
2. Prevention of losses through evaporation and seepage, and
3. All other hydrological studies and engineering interventions, aimed at conservation and efficient utilisation of the limited water endowment of an area such as a watershed.

Question 25. Write the three different names of Brahmaputra.
Answer:
1. Tsangpo in Tibet,
2. Brahmaputra in India,
3. Jamuna in Bangladesh.

Class 10 Geography Book West Bengal Board

Question 26. Canal irrigation is more found in North India. Why?
Answer: Canal irrigation is more found in North India due to
1. There are large numbers of perennial rivers in this region.
2. The Northern plains are flat and level, and the ground is soft to carve out. This has facilitated the construction of canals;
3. In this region the portion of arable land is the highest. As such, the construction of canals is economically very beneficial.

Question 27. Give three reasons with brief explanation for the necessity of irrigation in Indian agriculture.
Answer: Agricultural crops need water for their growth. In India, the monsoon is the main source of rainfall. But the monsoon in India has many drawbacks, viz.:
1. Uncertainty With regard to time and place, the monsoon rainfall is uncertain.
2. Irregular distribution of rainfall throughout the year is irregular.
3. Excessive and scanty rainfall in some areas excessive rainfall causes floods, whereas in others, scanty or no rainfall causes droughts.

Question 28. Name three east-flowing rivers of the Deccan.
Answer: Godavari, Krishna and Kaveri.

WBBSE Class 10 Geography Chapter 5 India – Drainage Of India 5 Marks Questions And Answers:

Question 1. State the differences between the physical characteristics of North and South Indian rivers.
Answer:

Question 2. What do you know about the Arabian Sea drainage or the west-flowing rivers of India?
Answer: The west-flowing rivers of India are:
(1)The Narmada (1,282 km): It rises from the Amarkantak peak of the Mahakal range and flows through the rift valley in between the Vindhyas and the Satpura range in the West and drains into the Gulf of Khambat. It makes a beautiful waterfall on the marble rocks named Dhauladhar at Bhorghat near Jabalpur.

(2)The Tapti (740 km): Tapi is also known as the Tapti river; it rises from the Mahadeo range and flows in a rift valley lying between the Satpura and Ajanta ranges towards the West. It drains into the Gulf of Khambat. The Surat port is situated in its mouth.

(3)The Mahi (503 km): It rises from the Vindhyan range. It flows northwards at first and then takes the southwestern course to join the Gulf of Khambat. Most of its course lies in Gujarat state.

(4)The Sabarmati (416 km): It rises from the Aravalli range and drains into the Gulf of Khambat flowing in the southwest direction. The major portion of its basin lies in the Gujarat state.

Class 10 Geography Book West Bengal Board

Other rivers: Other notable rivers are Amba, Sabitri, Sharavati, Bagabati, Saraswati, etc. Jog falls of Sharavati river is famous in India. It is the largest waterfall in the country.

Question 3. Compare and contrast the rivers of North India with that of South India.
Answer: Difference between the rivers of North India and those of South India.

Rivers of North India	Rivers of South India
Names of Rivers
1. The Indus and its tributaries, namely	1. The Narmada, the Tapti, the Sabarmati, the
Jhelum, Chenab, Ravi, Beas and Sutlej.	Subarnarekha, the Godavari, the Krishna, the
The Ganga and its tributaries, namely	Cauveryarethe rivers of South India.
Yamuna, Ramaganga, Gharghara, Gondak,
Burhi Gondak, Kosi, and the Brahmaputra
at its tributaries like Subansiri, Manas, etc.
are the rivers of North India.
Source of Water
2. They are fed by the melting of snow and	2. They are wholly rain-fed.
glaciers and also by rainwater.
Change of course
3. They are subject to drastic changes of	3. They flow through the stable region and do not
course, particularly after the landslides	change their course.
and earthquakes.
Altitude at source
4. They have originated at much higher	4. They have originated at much lower altitudes.
altitudes.
Winter Flow of Water
5, In winter their flow continues to be enhanced	5. In winter their flow is reduced and is to the minimum.
by water from the melting snow and glaciers.
Stages of River Course
6. Most of them possess three distinct stages	6. They do not show the three stages of a river.
namely upper, middle and lower courses.
Navigability
7. The middle and lower courses of these	7. Most of them are swift-flowing. They are
rivers are navigable.	navigable at the lower course.
Flood plain, etc.
8. They have developed a vast floodplain.	8. They have not formed any floodplain
The Ganga has formed the largest delta	except for the deltaic plains. Of the west flowing
at its mouth.	rivers like.the Narmada and the Tapti do
Meanders
9. The rivers of North India drain areas	9. The rivers of South India drain areas which .
which are comparatively unstable geology-	are comparatively more stable geologically
logically and form meander.	and are devoid of meanders.
Drainage
10. (a) The rivers of North India may broadly	10. (a) The rivers of South India may
be divided into the Bay of Bengal drainage	be divided broadly into the Bay of Bengal
and the Arabian Sea drainage. The Ganga	drainage, the Arabian Sea drainage and the
system and the Brahmaputra system	Geosyncline drainage. The Mahanadi, the
belong to the former and the Indus system	Godavari, the Krishna, and the Cauvery be
to the latter.	long to the Bay drainage. The Narmada, the
	Tapti, the Sabarmati belong to the Arabian
	Sea drainage. The Chambal, the Betwa, the
	Son form the Geosyncline drainage.
(b)    The Himalayas through its magnificent	(b) The Godavari, the Krishna, and the Cau-
gorges, rising sometimes to more than 5	very systems are examples of superimposed
km (Near Bunji) exhibits exemplary ante-	drainage pattern.
cedent drainage. The deep gorges cut
across the Himalayas provide momentum
to the major rivers of North India.
(c)    The rivers of North India are well	(c) The rivers of South India present const-
integrated and reveal a generalised dendritic	recited drainage owing to the faults, dykes
pattern. The drainage pattern resembles	quartz veins on the Peninsular foreland.
the branching of a tree.

Question 4. Describe the course of the east-flowing rivers of south India.
Answer:
1. Godavari (1465 km.)It is sometimes called the Ganga of the South. It rises from the Trambak Highlands of the Western Ghat ranges near the Nasik district of Maharashtra. It then flows southeastward and drains into the Bay of Bengal. It forms a large delta on its mouth after dividing itself into a number of distributaries. Indravati, Pengona, Wenganga, Pranhita, and Manjira are some of the important tributaries of Godavari.
2. SubarnarekaIt rises from the Chotanagpur plateau of Bihar and flows eastwards to drain into the Bay of Bengal near the Br are coast of Orissa.
3. MahanadiMahanadi rises froi n Sihawa Highlands of Raipur district of Madhya Pradesh. It flows through the Chattisgarh region and drains into the Bay of Bengal. It forms a large delta on its mouth. Brahmani and Baitarani are the two main tributaries of the river.
4. Krishna Krishna rises near Mahabaleshwar peak and drains into the Bay of Bengal. Bhima, Tungabhadra, Bedbati, etc. are its important tributaries. It forms a delta on its mouth.
5. The Kaveri The Kaveri (Cauvery) rises from the Brahmagiri Hills of Western Ghats near Coorg of Karnataka. It flows eastwards crossing the Ghats. The Timbavati, Bhavani, Shimla are the main tributaries of the Kaveri. After forming a delta, it flows into the Bay of Bengal. The Kaveri delta is very much fertile and known as the ‘Granary of the South’. Other rivers The other east-flowing rivers of South India are Paller, Penner, Ponnaiyer, Vaigai, Chittar, and others. These rivers flow into the Bay of Bengal.

Class 10 Geography Book West Bengal Board

Question 5. Give an account of the course, tributaries, and distributaries of the river Ganga.
Answer: Ganga:
The course of the Ganga: The main river of India is the Ganga. It stretches for 2510 km, but 2017 km of its length lies in India and the remainder lies in Bangladesh. The river can be divided into 3 parts from its source to its mouth.
They are: 1. Upper course of the Ganga, 2. Middle source of the Ganga and 3. The lower course of the Ganga.

1. Upper Course of the Ganga river: The river rises from the Gomukh ice cave at the snout of the Gangotri Glacier at a height of nearly 6600 m. The glacier lies in the Great or Himadri Himalayas, lying in Uttar Pradesh. Near its source, the river is known as Bhagirathi which also forms the main tributary of the Ganga. The Bhagirathi forms narrow V shaped valleys in the Himalayas while flowing to the southwest.

Near Devprayag it meets another important tributary of the Ganga called Alokananda. Higher in the mountains, to the north-east, Alokananda merges with another tributary of the Ganga, river Mandakini at Karnaprayag, and Bhagirathi or Ganga and the Alokananda river is called the Ganga-river, which flows over the Shivalik (Siwalik) ranges southwards, until it reaches the plains at Haridwar. Thus from the source to Haridwar lies the mountain course or upper course of the Ganga.

Any river that shows the dominance of erosive activity in the mountain or upper course and the dominance of deposition activity in the delta or lower course, is called an ideal river. The course of the river Ganga shows these characteristics clearly, so the river Ganga is called an ideal river.

Class 10 Geography Book West Bengal Board

2. Middle course of the river Ganga: The Ganga river initially flows southwards from Haridwar and then turns to the east flowing over the states of Uttar Pradesh and Bihar. Near the Rajmahal hills in Bihar, the Ganga takes another southward curve and enters into the state of West Bengal. The length of the Ganga from Haridwar to the Rajmahal hills forms the Plains or Middle Ganga Plain region.

3. The delta or lower course of the Ganga: The Ganga river moves around the Rajmahal hills to the east and then turns south to enter the state of West Bengal. So the river enters West Bengal and then near Dhulian in Murshidabad it divides into the Padma and Bhagirathi distributaries. The main distributary of the Ganga is called Padma initially, and later it is called Meghna before it drains into the Bay of Bengal. The feebly flowing second distributary is called Bhagirathi-Hugli, which flows through West Bengal to drain into the Bay of Bengal. The course of the Ganga between the Rajmahal hills and its mouth near the Bay of Bengal is called the lower course or Delta course of the Ganga. The largest delta in the world has been formed by the Ganga at its mouth.

Tributaries of the Ganga river: The main tributary of the Ganga is Yamuna. It rises from the snout of the Yamunotri Glacier in Uttar Pradesh. It meets the Ganga at Allahabad; it is also called Prayag. Some important tributaries of the Yamuna are Chambal, Betwa, Ken, etc. They all rise from the Central Highlands to the south of the Northern Plains and are fed by rainwater. Yamuna forms the main snow-fed and right bank tributary of the Ganges. Some other tributaries of the Ganga are Ramganga, Gomati, Ghaghara, and Gandakand Kosi. These rivers join Ganga on its left bank and are all fed by the snowmelt waters of*the Himalayas. Among other right bank tributaries of the Ganga rising from the southern plateau, the most important is Son. It is rain-fed. Some tributaries of the “Bhagirathi-Hugli distributary of the Ganga river are— Damodar, Mayurakshi, Ajay, Rupnyarayan, etc. They are all rain-fed.

Distributaries of the Ganga river: Near Dhulian in the Murshidabad district of West Bengal, the Ganga river divides into two distributaries-Padma and Bhagirathi- Hugli. When the Bhagirathi-Hugli flows past the district of Hugli, it is called the Hugli river. According to some views, the intrusion of saline water from the sea at high tide is the part of this river which is called Hugli. The distributaries of the Bhagirathi-Hugli are Bhairab, Jalangi, Bidyadhari, Mathabhanga, etc.

School Geography Class 10 WBBSE

Other characteristics of the Ganga: The Ganga river shows various features-‘V’ shaped valleys, wide valleys, meandering course, ox-box lakes, flood plains, natural levees, deltas, etc. along its course from source to mouth. Ganga contributes 14% of the total water flow in India. The Ganga basin has 26% of the total hydroelectric potential of India. Many famous towns and market centres are located on the banks of the Ganga, such as— Haridwar, Allahabad, Kanpur, Benaras, Kolkata, Patna, etc.

Question 6. Give a brief account of the river Brahmaputra.
Answer:
1. The course of the river Brahmaputra: The Brahmaputra is the most important river in Eastern India. It rises from the Chemayang Dung Glacier which is located 90 km southeast of the Rakhas Tal and Manasarovar in Tibet. From this source, Brahmaputra flows eastwards for nearly 1500 km in Tibet. Here the river is known as Tsangpo. Near Namcha Barwa peak the Brahmputra makes a southward turn, cuts across the Himalayas, and enters Arunachal Pradesh where it is called Dang. The Dihang enters Assam near Sadiya to meet the Lohit river and Dibang river.

These 3 rivers join and flow through Assam from the northeast the west and is called the Brahmaputra river. At Dhubri in western Assam, the Brahmaputra takes a southward turn and enters Bangladesh where another tributary the Tista meets it from India. The combined water is then called Jamuna in Bangladesh. Further south the Jamuna meets the Padma and they together drain into the Bay of Bengal. The total length of the Brahmaputra river is nearly 2580 km, of which in India only 885 km flow.

2. Tributaries of the Brahmaputra: Dibang and Lohit are the most important tributaries of the Brahmaputra. The other tributaries are Subansiri, Bharali, Torsa, and Tista which join it on its right bank, while on its left bank, Buridihi, Dhansiri, Kopili, etc. tributaries join it.

3. Other characteristics of the Brahmaputra: The Brahmaputra river flows slowly over the Assam valley due to the gentle slope of the land. Thus the river flows through pronounced meanders and has many sandbanks and islands along its channel. The largest river island in the world lies on this river and is called Majuli island. This island has an area of about 929 sq km. Frequent earthquakes in the Assam valley have caused the Brahmaputra to change its course quite often.

Question 7. Give an account of the distribution of lakes and other water bodies.
Answer: Lakes, water bodies, and canals are distributed all over India. A brief discussion of these water bodies is given below:

Lakes: Lakes are of two types in India:
1. Lakes of the Himalayas and North India, and
2. Lakes of south India

Type of Lake	Names of Lakes	State/where found	Nature of lake
Himalayan and North Indian Lakes	Nainital, Sattal, Bheematal, Punatal, Khurpa Tal	Kuman Himalaya, U.P.	Freshwater Lake
	Dal lake, Wular lake, Harnag, Dudhnag	Kashmir Himalaya	Freshwater lake
	Tso Moriri, Saltlake Pangong lake	Ladhak	Brackish water lake
	Logtak lake	Manipur	Freshwater lake
	Sambhar, Didwana Chapper, Kachar	Rajasthan	Brackish water lake
Lakes of South India	Lunar lake	Maharashtra	Crater lake (brackish water lake)
	Chilika lake	Coastal Bay of Bengal Odisha	Largest brackish water lake in India
	Kolleru lake	In between Godavari and Krishna delta in Andhra Pradesh	Freshwater lake
	Pulicat lake	Tamil Nadu	Brackish water lake
	Vembanad, Astamudi Kayals	Malabar coast of Kerala	Brackish water lake

 

Among the water bodies of India reservoirs, tanks, ponds, beels, ox-bow lakes derelict water, and brackish water cover about 7 M Ha of area. The southern States of Andhra Pradesh, Karnataka, Tamil Nadu along with West Bengal, Rajasthan, and Uttar Pradesh account for 62% of the total area under tanks and ponds, and reservoirs in the country. More than 77% of bees, oxbow lakes, and derelict water lies in the states of Odisha, U.P., and Assam. Brackish water is found in Odisha, Gujarat, Kerala, and West Bengal.

The total reserve of inland waterbodies in India is unevenly distributed though the majority of them lie in the states of Odisha, Andhra Pradesh, Gujarat, Karnataka, and West Bengal. Uttar Pradesh occupies the first place with the total length of rivers and canals as 31.2 thousand km which is about 17% of the total length of rivers and canals in the country. Other states following Uttar Pradesh are Jammu and Kashmir and Madhya Pradesh. Some important canals of India are the west-Yamuna canal, Upper Ganga canal, Lower Ganga canal of U.P., Hijli canal, Medinipur canal, canals of Damodar, Mayurakshi, Kasai, canals of Rajasthan in North India and canals of the rivers of South India.

Question 8. Write the importance of river bodies from a human perspective.
Answer:
Important of River Bodies from a Human Perspective: Rivers, lakes, ponds, reservoirs, canals, etc. are important from a human perspective because of the following reasons:
1. They provide fresh water which is best to use for drinking,
2. They supply water for agricultural, domestic, and industrial uses,
3. These water bodies produce power in the form of hydropower, hydroelectric and thermoelectric,
4. They are natural wildlife habitats for many different species,
5. Lakes and ponds regulate soil formation, biodiversity, groundwater recharge, and flood,
6. They are most commonly used for recreation like swimming, boating, fishing, nature viewing, etc.
7. They supply irrigation water to the agricultural fields.
8. They have moderating influence on the climate of surrounding regions,
9. As parts of the hydrological cycle they help in maintaining balance in nature.

School Geography Class 10 WBBSE

Question 9. What do you understand by the overuse of groundwater? State its impacts.
Answer:
Overuse of groundwater and its impact: Groundwater is the largest source of usable fresh water. It is widely used in areas deficient in surface water. Groundwater is readily used in domestic, agricultural, and industrial fields. Sustained groundwater pumping causes depletion of its level. In India, the number of wells showing a fall in groundwater level is 5,699 (2003-12) according to reports from the Ministry of Water Resources. The states where the groundwater table has declined considerably are Tamil Nadu (76%), Punjab (72%), Kerala (71%), Karnataka (69%), Meghalaya (66%), Haryana (65%), West Bengal (64%) and Delhi (62%).

Some of the adverse effects of groundwater depletion are:
1. Lowering of the water table,
2. Increased cost for pumping farther to reach the water table,
3. Reduced surface water supply, as groundwater and surface water are connected with each other,
4. Land subsidence occurs when there is a loss of support belowground,
5. Excessive pumping in coastal areas causes salt water to move inland resulting in contamination of the water supply.

Question 10. Write what do you know about Damodar Valley Corporation.
Answer:
Damodar Valley Corporation: The River Damodar (in Eastern India) was known for frequent floods resulting in the destruction of life and property. The river runs 541 km from its origin in the Khamerpet Hills in the eastern part of India, to meet the river Hugli. The basin area is 17,506 sq. km. The corporation was jointly formed by the government bodies: the Central Government, the Government of West Bengal, and the Government of Bihar (presently Jharkhand) to participate jointly for the purpose of building the Damodar Valley Corporation. The Damodar runs through some of the most mineral-rich regions of India. The basin provides the country with valuable minerals, such as coal and iron ore. There is also considerable agriculture in the region, with rice and potatoes being the major crops.

The river Damodar is entirely rain-fed. About 80% of the annual discharge occurs during the four monsoon months from June to September. This seasonality and the consequent imbalance in its flow had resulted in frequent flash floods, which gave the Damodar its epithet – River of Sorrow. To tame the violent river, a scheme was launched in the 1950s and the Damodar Valley Corporation came into being. The scheme essentially involved the construction of dams along the length of the river, so that the flow remained a part of the total system of water management. DVC dams are capable of moderating floods of 6.51 lac cusec to 2.5 lac cusec. With time DVC developed six thermal power stations at Bokaro.

Chandrapura and Durgapur, three hydroelectric power stations at Tilaiya, Maithon, and Panchet with a capacity of 144 MW, and one gas turbine station with a capacity of 82.5 MW. Presently DVC has 35 sub-stations and also four dams, a barrage, and a network of canals that play an effective role in water management. The construction of check dams, development of forests and farms, and upland and wasteland treatment developed by DVC play a vital role in eco-conservation and environment management. A flood reserve capacity of 1292 mcm has been provided in 4 reservoirs. Water is stored in the 4 DVC reservoirs to supply 680 cusecs of water to meet industrial, municipal and domestic requirements in West Bengal and Jharkhand. A barrage on river Damodar was constructed in 1955 at Durgapur to supply of irrigation water to the districts of Burdwan, Bankura, and Hooghly in West Bengal.

School Geography Class 10 WBBSE

Question 11. What do you mean by watershed management and rainwater harvesting?
Answer:
Watershed and watershed management: The highland that separates two adjacent river catchment areas is called a ‘watershed’. They are important because the flow of water in the catchment area, the speed, and volume of water, the amount of silt generated, etc. depend on the nature of the watershed. They are natural highlands that influence the characteristics of rivers and their basins. But sometimes they are manipulated by ‘watershed management’.

This refers to the scientific use and utilization of water resources to stop soil erosion, increase fertility, control floods, prevent siltation of river beds, and maintain proper land use patterns. Some methods of watershed management are strip cropping, grassland farming, terracing, construction of check dams, construction of farm ponds, etc. E.g.- the Kothapally watershed management program (1999) in Andhra Pradesh-this program has taken up soil and water management programs, enhanced crop and livestock farming, increased income levels, increased greenery, and decreased soil run-off.

Rainwater harvesting: Rainwater harvesting is the accumulation and storage of rainwater for reuse rather than allowing it to run off. Its uses include harvesting water for gardening, livestock, irrigation, domestic use, etc. It can also be used as drinking water.

Advantages: Rainwater harvesting provides an independent water supply during regional water restrictions like droughts. It can mitigate flooding of lowlands. It helps to sustain groundwater levels. It ensures the availability of potable water, is clean and free from salinity.

School Geography Class 10 WBBSE

Question 12. Write the role of Tamil Nadu in rainwater harvesting.
Answer:
Rainwater Harvesting in Tamil Nadu: The Rainwater Harvesting movement launched in 2001 was the brainchild of the Honourable Chief Minister of Tamil Nadu. It had a tremendous impact in recharging the groundwater tables all over Tamil Nadu. According to Building Rules 1973, it is made mandatory to provide Rainwater Harvesting (RWH) structures in all new buildings. Town Panchayats had undertaken the construction of new RWH structures and the renovation of old structures. Out of 23,92,457 buildings in Town Panchayats about 22,94,342 buildings are provided with Rainwater Harvesting facilities. Awareness programs, the erection of hoardings displaying the importance and benefits of RWH, and participation of NGOs were action plans of this program. RWH structures have been provided to buildings that belong to Town Panchayat departments.

Two techniques of RWH were followed:
1. Storage of rainwater on the surface for future use.
2. Recharge of groundwater: For storage, the structures used are: pits (for recharging shallow aquifers), trenches (depending on the availability of permeable streams), dug wells, hand pumps, recharge wells, etc. Water in secure households or individuals are the ones to benefit the most from Rainwater Harvesting in the state. This program is thus visualised to improve water supply, food production, and food security for the people of Tamil Nadu.

Question 13. What are the drawbacks of the conventional method of irrigation?
Answer:
Drawbacks of Conventional Method of Irrigation: Conventional irrigation systems suffer from a number of constraints leading to improper utilization of water. These are the following:
1. In the conventional system of irrigation a large quantity of water is not properly utilised.
2. Crops are usually subjected to cyclic changes of flooding and water stress situations, by providing heavy irrigation at one time and leaving the fields to dry up for about 10 to 15 days. The moisture availability to the crops, therefore, keeps on changing. This results in poor yields in the crops.
3. The fields situated in low areas always get excess water causing prolonged water Egging. Thus, crops are subjected to water logging resulting in poor yields.
4. In the fields about 10-15 percent of land is utilized for preparing channels and distributions, etc. which decreases the effective area of cultivation.
5. Extensive areas of land in the arid and semi-arid regions of India have gone out of cultivation due to the accumulation of salts. Excessive irrigation and poor water management are the main reasons of water logging and gradual build up of excessive salts. Progressive build-up of soil salinity has made the soils unsuitable for cultivation.

Question 14. How did the Indian river system evolve?
Answer: Before we proceed to know about the present nature of the drainage system, it is necessary to understand its evolution. The present drainage of India is the result of the long process of evolution. Two broad divisions of the drainage of India can be recognised on the basis of their evolution.
They are:
1. The Himalayan rivers, and
2. The Peninsular rivers.

The Himalayan Rivers: Three major rivers of the Himalayas-the Indus, the Ganga, and the Brahmaputra- originate on the southern slopes of the Tibetan Highlands. They first flow parallel to the mountains and then take a sudden bend towards the south cutting deep gorges in the Himalayan ranges. The gorges of the Indus, Satluj, Alaknanda, Gandak, Kosi, and Brahmaputra clearly indicate that these rivers existed even before the Himalayan ranges were formed. These rivers continued to flow by cutting the mountain ranges as these ranges rose, leading to the formation of deep gorges. Thus, the Himalayan rivers are typical examples of antecedent drainage.

The Indobrahm Theory: According to geologists, the Shiwalik hills run parallel to the main Himalayan ranges and are formed of alluvial deposits consisting of sands, clays, and boulder conglomerates. These deposits were laid down by a mighty stream that flowed from Assam to Punjab and even beyond upto Sind. It finally emptied itself into a gulf that occupied parts of Sind and lower Punjab in the Miocene period. This stream is known as the ‘Indobrahma’ or the ‘Shiwalik’ river. This river carried the combined flow of the three main rivers—the Indus, the Ganga, and the Brahmaputra—and deposited huge quantities of alluvium. Later.

This mighty stream dismembered into the following systems and sub-systems:
1. The Indus,
2. The five tributaries of the Indus in Punjab,
3. The Ganga and its Himalayan tributaries, and
4. The stretch of the Brahmaputra in Assam and its Himalayan tributaries.

The dismemberment was the result of the following two events:
1. Upheavals in the western Himalayas including the Potwar Plateau in the Pleistocene age.
2. Headward erosion by the tributaries of the Indobrahma river.
As a result of the above-mentioned dismemberment of the Indobrahma river, the Indus and its tributaries, the Ganga and its tributaries, and the Brahmaputra and its tributaries came into being. It is supposed that the Yamuna was first a tributary of the Indus, but it was annexed by the Ganga later on and it became a tributary of the Ganga.

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The Peninsular Rivers: The broad, graded, and shallow valleys of the Peninsular rivers indicate that these rivers existed much before the Himalayan rivers came into being. These rivers have acquired maturity and do-mostly lateral cutting instead of vertical cutting. Most of the rivers flow from west to east with notable exceptions of Narmada and Tapi, These two rivers flow in troughs which have not been formed by them. The Western Ghats used to form the original watershed. But, due to the submergence of the western flank of the Peninsular block, the general symmetry of the Peninsular rivers was disturbed. The second distortion took place at the time of the formation of Himalayan rivers when the northern flank of the Peninsular block suffered subsidence and, consequently, trough-faulting took place. The Narmada and the Tapi flow in such trough faults and represent consequent drainage.

Question 15. Write the merits and demerits of canal irrigation.
Answer:
Merits of Canal Irrigation:
1. Most of the canals provide perennial irrigation and supply water as and when needed.
This saves the crops from drought conditions and helps in increasing farm production.
2. Canals carry a lot of sediment brought down by the rivers. This sediment is deposited in the agricultural fields which adds to the fertility of the soil.
3. Some of the canals are parts of multipurpose projects and, therefore, provide a cheap source of irrigation.
4. Although the initial cost involved in canal irrigation is much higher, it is quite cheap in the long run.

Demerits of Canal Irrigation :
1. The canal water soaks into the ground and leads to the problem of water-logging along the canal route.
2. Excessive flow of water in the fields raises the groundwater level. Capillary action brings alkaline salts to the surface and makes large areas unfit for agriculture. Vast areas in Punjab, Haryana, and Uttar Pradesh suffer from the problem of ‘reft caused by canal irrigation. About 36,000 hectares have been rendered useless in Nira Valley of Maharashtra due to high concentration of salts in the soil resulting from canal irrigation.
3. The marshy areas near the canals act as breeding grounds of mosquitoes which result in widespread malaria.
4. Many canals overflow during the rainy season and flood the surrounding areas.
5. Canal irrigation is suitable in plain areas only.

Question 16. Explain why deltas are not formed at the mouth of the west-flowing rivers of India.
Answer: The slope of the Western Ghats is steep and that is the reason that these rivers have a rapid flow. They don’t have to travel much distance to drain into the sea. As a result, they don’t carry many sediments required to form deltas.
1. The eastward slope consists of the Deccan plateau. In other words, the western coast is higher when compared to the eastern coast. Thus there is no ground presented for delta-based formation.
2. The west-flowing rivers come from the western ghat. The western coast consists of hard rocks. So it is not possible.
3. The hard rocks don’t allow west-flowing rivers to widen their mouth. Hence they formed estuaries instead of deltas.

Question 17. Why is irrigation necessary in Indian agriculture?
Answer: Agricultural crops need water for their growth. In India, the monsoon is the main source of rainfall. But the monsoon in India has many drawbacks, viz.
1. Uncertainty With regard to time and place, the monsoon rainfall is uncertain.
2. Irregular distribution of rainfall throughout the year is irregular.
3. Excessive and scanty rainfall in some areas excessive rainfall causes floods, whereas in others, scanty or no rainfall causes droughts.
4. Soils In some areas, soils have less water retaining capacity, so irrigation is needed.
5. For winter crops irrigation is a necessity because most of the monsoon rain falls in summer.
6. Irrigation is needed for some plants that are thirsty like jute, and paddy. ‘
7. To increase the yields, chemical fertilizer is essential and for this irrigation is necessary.
8. To feed the ever-rising population, crops should be grown throughout the year, hence irrigation is necessary.

Geography Class 10 Solutions WBBSE

Question 18. Mention the different irrigation systems practiced in India.
Answer:
The following methods are used for irrigation in India:
1. Wells: Wells are mainly used in areas having a large quantity of groundwater where it is tapped by digging down to the water table. Deeper wells irrigate larger areas and are lined with bricks, so we call them pucca wells. Irrigation by wells is done in U.P., Punjab, Haryana, Bihar, West Bengal, Andhra Pradesh, Tamil Nadu, and Maharastra because the soil there is soft and porous and sub-soil water is near the surface of the earth. There are about 50 lakh wells in India. About 25% of the total irrigated area is irrigated by wells.

2. Tube-wells: These consist of a deep bore dug into the ground with drilling equipment and water is drawn out with the help of a pump. Tube wells have proved very useful in the alluvia! plains of Punjab, Haryana, U.P., and Bihar. U.P. leads in tube-well irrigation. There are about 31,000 tube wells in the country and they irrigate about 60 lakh hectares of land. About 23% of the total irrigated area in India is served by tube- wells. In this way, wells and tube wells account for (25% + 23% = 48%) of the total irrigated area in India.

3. Canals: A canal is a big water channel taken out of a river and further divided into small distributaries in order to lead the river-water to the fields. About 45% of the total irrigated area is watered by canals. U.P., Punjab, Andhra Pradesh, Haryana, West Bengal, and Tamil Nadu are the leading states which use canal irrigation. These six states are having about 75% of the total canal-irrigated land.

There are two types of canals in India :
1. The inundation Canals: The inundation canals are those which flow during the rainy season when the rivers are in flood. These are simple but do not provide water all year round. These canals irrigate about 6% of the total irrigated area.
2. Perennial Canals: They draw their water from perennial rivers of artificial lakes. They are very useful for irrigation all throughout the year. They irrigate about 39% of the total irrigated area. Some of the important canals are the Western and Eastern Yamuna canals, Sirhind canals, Upper Bari Doab canals, Upper Ganga canals, etc.

Question 19. What do you mean by canal irrigation? Mention the areas where canal irrigation is found in India.
Answer: India has one of the world’s largest canal systems stretching over more than one lakh kilometres. The irrigation canals are of two types:
1. Inundation Canals: These canals are taken out directly from the rivers without constructing any barrage or dam. Such canals use the excess water of rivers at the time of floods and remain operational during rainy season. As the beds of these canals are at a level higher than those of the rivers, they get supply of water only when the rivers are in flood. Therefore, these canals have limited use.

2. Perennial Canals: These canals are taken out from the perennial rivers by constructing barrages to regulate the flow of water. Most of the canals in India belong to this category. Canal irrigation is in practice in Uttar Pradesh, Madhya Pradesh, Andhra Pradesh, Rajasthan and Haryana, Jammu and Kashmir, Assam, and Tripura. Canals also supply water to a sizeable part of the irrigated area in Bihar, Orissa, Karnataka, Tamil Nadu, and West Bengal. Mizoram, the least irrigated state, is solely dependent on canals. The northern Great Plains have elaborate system of canals.

Important canals in Punjab: Haryana is Upper Bari Doab, Bist Doab, Sirhind, Bhakra, and Western Yamuna canals. The Indira Gandhi canal, Bikaner canal, and the canals of the Chambal projects are major canals in Rajasthan. Canals in Uttar Pradesh include the Eastern Yamuna Canal, Sharda canal, Ramganga canal, and Betwa canal. In south India, the canals of the Nizamsagar, NagarjunasagarandTungabhdra projects and of the Krishna and Godavari deltas are the major ones. In Tamil Nadu, nearly one-third of the net irrigated area is under canal irrigation.

Question 20. What are the advantages and disadvantages of tube-well irrigation?
Answer:
Advantages of Tube-well Irrigation:
1. A tube well can irrigate about ten times more area than an ordinary well.
2. It is operated by an electric motor or by a diesel engine and water can be easily lifted from greater depths.
3. It is the most suitable source of irrigation in areas where canal irrigation is not available.
4. A tube well is an independent source of irrigation and can be used by the farmer whenever the crops need water.
5. Several chemicals are mixed with tube-well water. Such chemicals add to the fertility of the soil.

Geography Class 10 Solutions WBBSE

Disadvantages of Tube-well Irrigation:
1. Although it can irrigate a much larger area than an ordinary well, a tube well can irrigate only a limited area which is much less than the area irrigated by canals.
2. The farmer has to spend money regularly on electricity or diesel.
3. This source of irrigation is not fit for areas of brackish groundwater.
4. A tube well can draw a much larger quantity of water. Thus the groundwater level goes down and large-scale depletion of groundwater takes place. The groundwater level has already gone critically down in several areas of Punjab and Haryana where rice culture, requiring larger quantities of water, has become popular during the last few years.
5. In the event of drought the groundwater level falls critically below the required level and the water is not available when it is needed the most.

Geography Class 10 West Bengal Board Chapter 6 Satellite Imaginary And Topographical Map True Or False Type:

Question 1. For the analysis of satellite imagery, the use of a computer is mandatory.
Answer: True

Question 2. Red coloured lines are used to show roads in satellite images.
Answer: False

Question 3. ‘Platform’ is the place in space where the satellites are installed.
Answer: True

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 4. Different symbols are used to show geographical features in satellite images.
Answer: False

Question 5. The polar-orbiting satellites orbit at 800-900 km elevation.
Answer: True

Question 6. The topographical maps show large areas in greater detail.
Answer: False

Geography Class 10 West Bengal Board

Question 7. The scale of satellite imagery is predetermined.
Answer: False

Question 8. Topographical maps can be read in poor light conditions.
Answer: False

Question 9. Relative relief is readily found in satellite images.
Answer: False

Question 10. Satellite images can be prepared in a short time.
Answer: True

Class 10 Geography WBBSE Chapter 6 Satellite Imaginary And Topographical Map Fill In The Blanks Type:

Question 1. Indian Space Research Centre is situated at ______.
Answer: Bengaluru.

Question 2. The scale of the satellite image is true only at the ______ point.
Answer: Principal.

Question 3. Topographical maps do not show ______ information.
Answer: Up to date.

Question 4. The full form of R.F. is ______.
Answer: Representative, Fraction.

Class 10 Geography WBBSE Chapter 6 Satellite Imaginary And Topographical Map Very Short Answer Type:

Question 1. In what form the satellite imagery is produced?
Answer: FCC/digital data.

Question 2. Which colour is used for showing perennial rivers in topographical maps?
Answer: Blue.

Question 3. In which type of map, relief is shown by contour lines?
Answer: Topographical sheet.

Geography Class 10 West Bengal Board

Question 4. In what form are the satellite images produced?
Answer: Digital Number.

Question 5. What are used to generate satellite images?
Answer: Digital camera with charged coupled devices.

Question 6. Where is the scale found in a topographical map?
Answer: At the bottom centre of the map.

Question 7. What is the other name of the statement of scale?
Answer: Verbal scale.

Question 8. Who is responsible to prepare topographical maps?
Answer: Survey of India.

Class 10 Geography West Bengal Board

Question 9. Who prepares satellite images in India?
Answer: Indian Space Research Organisation (ISRO).

Question 10. Where is the head office of Survey of India located?
Answer: Dehradun, Uttaranchal.

Question 11. What is the other name of topographical maps?
Answer: Contour maps.

Question 12. When was the Survey of India Department established?
Answer: In 1767.

Question 13. Where is the headquarters of Survey of India Department?
Answer: At Dehradun.

Class 10 Geography West Bengal Board Chapter 6 Satellite Imaginary And Topographical Map 2 Marks Questions And Answers:

Question 1. State the definition of satellite imagery.
Answer:
Satellite imagery: The images prepared by information sent by the satellites are called satellite imagery. These are prepared by reading and representing the signals sent by the satellites with the help of high technological know-how.

Question 2. State the use of Representative Fraction (R.F.).
Answer: Commonly known as R.F., this scale is represented as a ratio between ground and map distances. E.g-1:50,000, meaning 1cm on the map represents 50,000 cm on the ground.

Geography Class 10 West Bengal Board

Question 3. Define topographical map.
Answer:
Topographical map: The map that represents the physical as well as cultural features of a place at a time with the help of certain colours and conventional symbols, is called a topographical map.

Question 4. What are the Geostationary satellites?
Answer:
Geo-stationary Satellite: Geostationary Operational Environmental Satellites (GOES) remain above a fixed location on the earth’s surface, approximately 22,500 km above the equator. They rotate at the same speed as the earth and so they always view the same portion of the globe.

Question 5. What is “Remote sensing”?
Answer: Remote sensing is the method of gathering information about any region or object on the earth’s surface or the surface of other planets from a considerable distance, without coming in physical contact. This information helps in analysing the region or the object.

Question 6. What is the importance of a topographical map?
Answer: It gives detailed information on the concerned area.

Question 7. What is the scale of a one-degree map?
Answer: It is 1/4 inch :1 mile or 1″: 4 miles or1: 2,50,000.

Class 10 Geography West Bengal Board

Question 8. Which series has been prepared according to directions?
Answer: The series having a scale of 1/2 :1 mile or 1″: 2 miles and having a latitudinal and longitudinal extent of 1/2 or 30′ is prepared according to direction. The latest series of 1 : 25,000 scale having 7 1/2 latitudinal and longitudinal extent is also prepared according to directions

Question 9. Why are satellite images powerful tools of meteorologists?
Answer: Satellite images are powerful and important tools used by meteorologists to forecast the behaviour of the atmosphere. They give a clear, concise and accurate representation of atmospheric events.

Question 10. What do you mean by the sensor?
Answer:
Sensor: A sensor is a specialized camera that is installed in a satellite in order to take photographs of the earth.

Question 11. What is a linear scale?
Answer: This is just a line drawn on a map of known ground length. It represents the same relationship by means of a straight line which is divided into certain lengths, each of which represents a certain distance on the ground. It has usually a primary division and a second division. This scale allows quick visual estimation of distance. This scale will remain valid if it is enlarged or reduced by the same amount.

Question 12. Mention the different names of toposheets prepared according to scale.
Answer:
1. Million Sheet,
2. Degree Sheet,
3. 1/2″ sheet,
4. 1″ sheet.

Question 13. What is a polar-orbiting satellite?
Answer: The polar orbiting satellites orbit at 800-900 km elevation and observe a new path on each orbit.

Question 14. Name two imaging satellites.
Answer: Geo-eye, Digital Globe.

Geography Class 10 West Bengal Board

School Geography Class 10 WBBSE Chapter 6 Satellite Imaginary And Topographical Map 3 Marks Questions And Answers:

Question 1. Give an account of different types of scales in tabular form as used in “topographical maps”.
Answer:

Topographical sheet	Scale (R.F.)	Latitudinal and longitudinal extent	Map No.	Example
Million sheet	1:10,00,000	4°x4°	40 to 90	73
Degree sheet	1:2,50,000	l°xl°	A to P	73 M
Half-degree sheet »	1:50,000	3°x3°	NE, NW,	73 M/E
Fifty thousand	1:50,000	15°x15°	1 to 16	73 M/16
sheet or 15-minute sheet
Special sheet	1:25,000	5°x7°30°	1 to 6	73 M/16/4

Question 2. Distinguish between Geostationary and Sun-Synchronous satellites.
Answer: Distinguish between Geostationary and Sun-Synchronous satellites:

Geostationary Satellites	Sun-Synchronous Satellites
1. The artificial satellites that orbit the earth from west to east in circular orbits at the same time as that of the earth’s rotation (24 hours), are called geostationary satellites.	1. The Sun-synchronous satellites are those which are installed on a geocentric orbit that combines altitude and inclination in such a way, that the satellite passes over any given point of the planet surface at the same local any given point of the planet’s surface at the same local solar time.
2. They are installed at a height of 36,000 km. approximately, above the equator.	2. They are installed at 700-800 km. above the land surface and orbit the earth in circular or elliptical paths from the north pole to south-polar regions.
3. e.g., GOES-E, GOES-W, etc.	3. e.g., IRS, LANDSAT, etc

Question 3. Briefly discuss three main characteristic features of satellite imagery.
Answer:
Characteristics of satellite Images:
The characteristics of satellite images are as follows:
1. These are produced in digital form.
2. Satellite images are generated from line scanners and digital cameras.
3. a Basic element of these images is a pixel.
4. They possess row and column structures.
5. Scan lines may be observed.
6. Zero is a value that does not indicate the absence of data.
7. Images can be generated for any part of the Electro-Magnetic (EM) spectrum.
8. Every point on the image has a certain digital number.
9. Colour of the image can be changed during processing.

Class 10 Geography West Bengal Board

Question 4. Mention the merits and demerits of remote sensing.
Answer:
Merits of satellite imageries:
1. The imageries can give a synoptic view of the earth in 23 cm x 23 cm maps. Also, some imageries may represent an area as large as 30,000sq. km in one map.
2. Information of resources and physical processes working in rugged and difficult terrains can be gathered easily. Information regarding oceans are also available.
3. Clear images of the earth can be taken even if there is heavy cloud cover.
4. The information gathered is digital in nature, hence they can be analysed easily with precision with the help of computers, 5. Weather forecasts and regular updates regarding physical processes can be gathered.

Demerits of satellite imageries:
1. Images cannot be taken in cloud cover without the help of microwave sensors.
2. Critical survey of minute areas is not possible.
3. The actual height or size of any object cannot be determined accurately.
4. Similar objects lying adjacent to each other are difficult to assess and explain.
5. The whole process of acquiring imageries is very expensive.

Question 5. What are the differences between Topographical Map and Satellite Imagery?
Answer:

Question 6. Discuss three major uses of satellite imagery.
Answer: Uses of satellite imageries:
1. The satellite imageries may be of the total hemisphere or a segment of the earth’s surface.
2. Information on relief, and physical processes, such as works of rivers, wind, glaciers, etc., distribution or resources, groundwater resources, etc. can be gathered easily by studying satellite imageries.
3. Imageries of rugged terrains, such as mountainous regions can be captured easily.

Question 7. Write a note on topographical maps.
Answer:
Topographical Maps: Topographical map shows the surface features of the Earth in detail (as much as the scale permits). The term topography is derived from the Greek word ‘topos’ meaning ‘a place’ and ‘grapho’ meaning ‘draw’ or ‘depict’. Topographical maps show natural and man-made features on the map as it exists during the time of the survey. These maps show small areas in greater detail. The maps are usually large-scale maps, varying from 1: 2.50,000 to 1: 25,000. Natural features like relief, drainage, water bodies, natural vegetation, etc. and man-made features like villages, huts, railway stations, roads, post offices, temples, etc. are shown on the map with the help of conventional signs and symbols. It contains all information about the physical and regional features of an area and hence forms an important tool for a geographer.

Geography Class 10 Solutions WBBSE

Question 8. What are the segments in the preparation for satellite imagery?
Answer: There are three segments or phases in preparing satellite imagery. They are:
1. Space segment: Sending of the satellite to space and setting it to orbit.
2. Sensor segment: The sensor or the camera senses the object or region whose photograph needs to be taken.
3. Ground segment: The satellite sends the sensed information and the photograph of the object or region observed. Imageries are produced by the Indian Space Research Organisation (ISRO) in India.

Question 9. State a few characteristics of a topographical map.
Answer:
Characteristics of Topographical Map:
1. The topo sheets are prepared to precise scales. Hence location or size of objects can be represented accurately.
2. Relief and landforms can be represented by spot heights accurately.
3. The accurate representation of drainage lines helps to understand the drainage pattern and nature of drainage.
4. Representation of settlements, transport system, etc. helps to understand the economic condition of the region.

Question 10. Write the importance of topographical maps.
Answer:
Importance of Topographical Maps: Topographical maps are a very important part of the study of Geography. Topo sheets give a pictographic representation of the original region with the help of various signs and symbols. It helps to understand the correlation between physical and cultural features present in an area. It helps to understand the problems and prospects of the regions, and hence helps in planning accordingly for the development of the place. Most importantly, as the maps are prepared after critically surveying the regions, all sorts of details are found in the maps.

Geography Class 10 Solutions WBBSE Chapter 6 Satellite Imaginary And Topographical Map 5 Marks Questions And Answers:

Question 1. Discuss the steps of acquiring satellite imageries.
Answer:
Step 1. Collection of ground samples: To extract useful information from satellite imagery, some information needs to be collected from the ground itself. This is commonly known as ‘ground samples’, ‘reference data’ or ‘field data’. This is needed to verify what exactly the satellite sensors are detecting. They should be taken close in time when the satellite sensor passes over the desired spot.
Step 2. Image acquisition: Currently there are several satellites in orbit with sensors capturing images of the earth. The desired sensor is chosen to capture images as per requirement. The image covers the area on the ground that the satellite sensor records.
Step 3. Processing of satellite imagery: Once the imagery is acquired, analysts typically go through a series of steps to prepare the imagery for analysis. Depending on its use and quality, sometimes satellite imageries need to be pre-processed, which means that cloud, haze and sun effects must be digitally removed. When mapping water features, all non-water areas like agricultural land, urban land and forests are masked out of the images to represent the water clearly.
Step 4. Creation of map: Once the mathematical relationship between the satellite data and the field data has been developed, it is applied to all pixels in the imagery to create a map. Once the pixels are classified into discrete classes like clarity level or vegetation type, these can be put into the Geographical Information System (GIS).

Geography Class 10 Solutions WBBSE

Question 2. What are the differences between Satellite imageries and topographical maps?
Answer: Difference between satellite imageries and topographical maps:

Question 3. Discuss the uses of different types of scales on topographical maps.
Answer: Map scale represents the relationship between the distance of any two points on the map and the actual distance between the same two points on the ground. It can be expressed as map distance between two points Scale – the ground distance between the same two points
The scale of the topographical map is found at the bottom centre of the map. There are three ways in which the scale of a map is expressed :
1. Statement scale.
2. Representative fractions and
3. Linear scale.

1. Statement scale: The statement scale or verbal scale states what distance on the map is equal to what distance on the ground, (for example, 2 cm -1 km). These scales are not usually printed on the topographical map.

2. Representative fraction: Representative fraction (R.F.) or fractional scale (for example 1: 50,000). Fractional scales do not have units. This scale is the ratio of the map distance to the equivalent distance on the ground using the same unit for both. There is flexibility to choose units.

So, we can write, 1 cm on the map = 50,000 cm on the ground or, 1 m on the map = 50,000 m on the ground, and so on.
We can convert the R.F. into a verbal scale.
Example: Convert 1: 50,000 into a statement of scale 1 cm on the map represents 50,000 cm on the ground or, 1cm: 50,000 cm.
or, 1cm: 50,000/100,000 km or, 1 cm : 1/2 km or, 1 cm : 0.5 km.

3. Linear scale: This is just a line drawn on a map of known ground length. It represents the same relationship by means of a straight line which is divided into certain lengths, each of which represents a certain distance on the ground. It has usually a primary division and a second division. This scale allows quick visual estimation of distance. This scale will remain valid if it is enlarged or reduced by the same amount.

Geography Class 10 Solutions WBBSE

Question 4. Write the characteristics of satellite images.
Answer:
Characteristics of satellite Images: The characteristics of satellite images are as follows:
1. These are produced in digital form.
2. Satellite images are generated from line scanners and digital cameras.
3. a Basic element of these images is a pixel.
4. They possess row and column structures.
5. Scan lines may be observed.
6. Zero is a value that does not indicate the absence of data.
7. Images can be generated for any part of the Electro-Magnetic (EM) spectrum.
8. Every point on the image has a certain digital number.
9. Colour of the image can be changed during processing.
10. Tone (relative brightness) is the most important element in image interpretation and analysis.
11. Size, shape (form or structure), texture (frequency of tonal variation), pattern (arrangement of visible features), height, shadow (relative height of a feature) site, an association of features, etc. are other important characteristics of a satellite image that help to interpret and analyse the image.

Question 5. What do you mean by satellite imagery? State its major types.
Answer:
Satellite imagery: It consists of images of the Earth or other planets collected by satellites. These images are used in various purposes like cartography, military intelligence or meteorology. It is a pictorial representation measuring the electromagnetic energy recorded by a sensor. Satellite images are powerful and important tools used by meteorologists to forecast the behaviour of the atmosphere. They give a clear, concise and accurate representation of atmospheric events. There are many different types of satellite images that can be taken with one satellite located out in space.

There are three main types of satellite images:
1. Visible imagery: The pictures can only be viewed during the day when clouds reflect the light of the sun. In these images the clouds show up as white, the ground is grey and the water is dark. They can predict developing thunderstorms even before they are detected by radar.
2. Infrared imagery: They are pictures of clouds or the earth’s surface identified by satellite sensors that measure the heat radiating from them. These images can be taken at any time of the day.
3. Water vapour imagery: They indicate the amount of water vapour present in the upper atmosphere. The highest humidities are the whitest areas and dry areas are dark.

Geography Class 10 Solutions WBBSE

Question 6. Write an account of the uses and importance of satellite images.
Answer: Satellite images have many applications in meteorology, oceanography, fishing, agriculture, forestry, biodiversity conservation, landscape, geography, cartography, regional planning, education, military intelligence and warfare. A summary of the uses of satellite images is given below:

Satellite images are essentially the eyes in the sky. They are the storehouses of information used in several branches of science like meteorology, geology, pedology, hydrology, oceanography, zoology, botany, environmental sciences, etc. They are important and useful for cartography, pedology, oceanography, etc. as they can be acquired periodically and in a systematic manner. But they have special importance in Geography which encompasses almost all other sciences. It has now become an indispensable tool for the study of geography.

Question 7. State the merits and demerits of satellite imagery.
Answer:
Merits of satellite imageries:
1. The imageries can give a synoptic view of the earth in 23 cm x 23 cm maps. Also, some imageries may represent an area as large as 30,000sq. km in one map.
2. Information of resources and physical processes working in rugged and difficult terrains can be gathered easily. Information regarding oceans is also available.
3. Clear images of the earth can be taken even if there is heavy cloud cover.
4. The information gathered is digital in nature, hence they can be analysed easily with precision with the help of computers, 5. Weather forecasts and regular updates regarding physical processes can be gathered.

Demerits of satellite imageries:
1. Images cannot be taken in cloud cover without the help of microwave sensors.
2. Critical survey of minute areas is not possible.
3. The actual height or size of any object cannot be determined accurately.
4. Similar objects lying adjacent to each other are difficult to assess and explain.
5. The whole process of acquiring imageries is very expensive.

WBBSE Solutions for Class 10 Geography and Environment

Class 10 Geography West Bengal Board India – Industries Of India True Or False Type:

Question 1. One of the forest-based industries of India is the paper industry.
Answer: True

Question 2. Petrochemical Industry is called as “Modern Industrial Giant”.
Answer: True

Question 3. Ahmedabad is called the Manchester of India.
Answer: True

Read and learn all WBBSE Solutions For Class 10 Geography And Environment

Question 4. Salem steel plant is a steel industry.
Answer: True

Question 5. The Visveswaraiya Iron and Steel Ltd. gets iron ore from the Singbhum district of Jharkhand.
Answer: False

Question 6. Maruti Udyog Ltd. is situated at Gurgaon in Haryana.
Answer: True

Question 7. The IT industry employs about 1 million Indian population.
Answer: False

Question 8. Jamshedpur (Tata Iron and Steel Co.) is a Public Company.
Answer: False

Question 9. Bokaro Steel Plant is the largest steel plant in India.
Answer: False

Geography Class 10 West Bengal Board

Question 11. India is one of the leading nations in the world in cotton textile production.
Answer: True

Question 12. Manganese is one of the essential raw materials for manufacturing iron and steel.
Answer: True

Question 13. One of the problems of the Indian iron & steel industry is the availability of quality coking coal.
Answer: True

Question 14. Vadodra is noted for petrochemicals.
Answer: True

Question 15. The biggest petrochemical complex of India is situated at Haldia.
Answer: False

Question 16. Gurgaon is famous for its shipbuilding industry.
Answer: False

Question 17. Kayal in Gujrat is the largest oil refinery in India.
Answer: True

Question 18. A humid climate is favourable for the cotton textile industry.
Answer: True

Question 19. Heavy engineering industry centres have close proximity to the iron and steel centres in India.
Answer: True

Question 20. Chennai is famous for its aircraft industry.
Answer: False

Question 21. Coimbatore is known as the Manchester of south India.
Answer: True

Question 22. The Kolkata port plays an important role in the development of the jute industry.
Answer: True

Question 23. Kayali is a noted oil refinery.
Answer: True

Question 25. Dalmia Puram has the first cement factory.
Answer: True

Question 26. Dalmianagar has the first paper mill.
Answer: True

Question 27. Maulhandar is noted for copper melting.
Answer: True

Question 28. Raniganj has paper mills.
Answer: True

Question 29. Durgapur is called the Ruhr of India.
Answer: True

Class 10 Geography West Bengal Board India – Industries Of India Fill In The Blanks Type:

Question 1. Jamnagar is famous for _______ industry.
Answer: Oil refining & Petrochemical

Question 2. _______ city is called as the “Manchester of South India”.
Answer: Coimbatore.

Question 3. Heavy Engineering Corporation is situated at _______.
Answer: Ranchi/Hatia.

Geography Class 10 West Bengal Board

Question 4. Bhopal is noted for ______ industry.
Answer: Heavy Electricals.

Question 5. Rourkela is noted for the industry.
Answer: lron and Steel.

Question 6. ______ is entrusted with the iron & steel industry.
Answer: SAIL.

Question 7. Bhadrawatiiron & steel plant in run by _______.
Answer: Charcoal.

Question 8. ______ is noted for Heavy Engineering Industry.
Answer: Ranchi.

Question 9. ______ in Orissa is noted for a new steel plant.
Answer: Paradeep.

Question 10. Rupnagar is noted for ______ industry.
Answer: Aluminium.

Question 11. Rupnarayanpur is noted ______ industry.
Answer: Cable.

Question 12. Korput is noted for ______ industry.
Answer: Aircraft.

Question 13. Kanpur is noted for the industry.
Answer: Scooter.

Question 14. MAMC is situated at ______.
Answer: Durgapur.

Class 10 Geography West Bengal Board India – Industries Of India Very Short Answer Type:

Question 1. Where was the first cotton mill set up in India?
Answer: Ghusuri (West Bengal).

Question 2. Which city is called the Manchester of South India?
Answer: Coimbatore (Tamil Nadu).

Question 3. What is the full form of SAIL?
Answer: Steel Authority of India Ltd.

Question 4. Name the largest steel plant of India.
Answer: Bhilai (Chhattisgarh).

Geography Class 10 West Bengal Board

Question 5. Name the steel plant which is run by charcoal.
Answer: Bhadravati Iron and Steel Plant.

Question 6. Name the steel plant of Tamil Nadu.
Answer: Salem Iron and Steel Plant.

Question 7. Name one centre producing only diesel locomotives in India.
Answer: Marundi near Varanasi.

Question 8. Name one railway locomotive manufacturing unit of India under private management.
Answer: Telco, Jamshedpur. :

Question 9. Why is manganese used in the iron and steel industry?
Answer: Manganese is for hardening steel and for making ferromanganese.

Question 10. Which steel plant is run by charcoal?
Answer: Bhadarbati is the only iron and steel centre which is run by charcoal. It is in the state of Karnataka.

Question 11. Which industrial region is called the Ruhr of India?
Answer: Durgapur industrial region in West Bengal is called the Ruhr of India.

Question 12. Name the iron and steel plant at Bhadrabati.
Answer: Visweshwraya Iron and Steel Limited.

Question 13. Name one important centre of automobiles in India.
Answer: Gurgaon in Haryana (Maruti Udyog Ltd.).

Question 14. Name the Cottonopolis of India.
Answer: Mumbai.

Question 15. Name a major cotton textile centre in Gujarat.
Answer: Ahmedabad.

Question 16. Name-the most important centre of the cotton textile industry in Tamil Nadu.
Answer: Coimbatore.

Question 17. Name the biggest centre of the cotton textile industry of the U.P.
Answer: Kanpur.

Geography Class 10 West Bengal Board

Question 18. Name an iron and steel centre in Orissa.
Answer: Rourkela.

Question 19. Name the centre of the steel plant in Jharkhand set up in collaboration with the Soviet Union.
Answer: Bokaro.

Question 20. Name the centre of the steel plant in Chhattisgarh setup with the help of the Soviet Union.
Answer: Bhilai.

Question 21. Name a centre of steel plant in Tamil Nadu.
Answer: Salem.

Question 22. Name the oldest steel plant in India.
Answer: Jamshedpur.

Question 23. Name an Iron and Steel plant of India having a coastal location.
Answer: Vishakhapatnam.

Question 24. Which steel plant in India has been set up with the collaboration of the U.S.S.R?
Answer: Bhilai Steel Plant in Chattisgarh had been set up with the collaboration of U.S.S.R.

Question 25. Where is the biggest Iron and Steel factory of India located?
Answer: The biggest Iron and Steel Plant of India is located at Bhilai in Chhattisgarh.

Question 26. Which are the leading centres of the Cotton Textile Industry in India?
Answer: Ahmedabad in Gujarat/Mumbai in Maharashtra is the leading centre of the Cotton Textile Industry in India.

Class 10 Geography WBBSE India – Industries Of India 2 Marks Questions And Answers:

Question 1. What do you mean by “pure raw materials”?
Answer: An element that does not change its weight or mass when it is turned into the finished product. It contains no impurities that are burnt off or removed so the weight will remain the same.

Question 2. Name one agro-based and one forest-based industry of India.
Answer: Agro-based industries: Cotton textile, Jute textile, Sugar industry, Flour industry. Forest-based industries: Paper industry, Lumbering industry.

Question 3. What do you mean by information technology?
Answer: Information Technology is the application of computers and telecommunication equipment to store, retrieve, transmit and manipulate data in the context of a business or other enterprise. The term is now used as a synonym for computers and computer networks. Several other industries associated with Information Technology are —computer hardware, software, electronics, semiconductors, internet; telecom equipment, e-commerce and computer services.

Geography Class 10 West Bengal Board

Question 4. What is meant by the engineering industry?
Answer: The industry which uses iron and steel as its main raw material for the production of different types of machinery and other steel goods is called the engineering industry.
It can be divided into two categories:
1. Heavy Engineering and
2. Light Engineering.

Question 5. What are ancillary industries?
Answer:
Ancilliary Industries: Ancilliary industries are associated industries. They grow up when one major large-scale industry is set up.
Example: The engineering industry is an ancillary industry. It grows up depending on iron and steel produced by an iron-steel plant.

Question 6. Name one centre for each of the locomotive and petrochemical industries of India.
Answer:
Centre of Locomotive Industry: Mauradi (near Varanasi).
Centre of Petrochemical Industry: Ankleshwar (Gujarat).

Question 7. From where does the steel plant of Jamshedpur get the required minerals?
Answer: Jamshedpur is in Jharkhand. It gets an adequate supply of iron ores from the iron belt of Mayurbhanj and Singhbhum. Coal, Manganese, limestone, etc. are necessary for the growth of this industry. Coal is brought to Jamshedpur from Jharia coal fields, limestone is brought from neighbouring areas, and manganese from Madhya Pradesh.

Question 8. Why is Manganese required in the Iron and Steel industry?
Answer: Manganese is essential in steel making. A little manganese added to iron removes gases and acts as a ‘cleaner’ in the manufacture of steel. Further addition of manganese makes the steel tough and hard, and it does not rust easily.

Question 7. Name two agro-based industries except for the sugar industry. Why is the sugar industry now shifting from North India to South India?
Answer: Two agro-based industries are the cotton textiles industry and the jute industry. The sugar industry is now shifting from North to South because of the following reasons:

1. The sugar content in sugarcanes is 10.5% higher in southern states than in the north.
2. It is a seasonal industry and is suited to the cooperative sector which is better organised in the south.

Question 8. Name two centres where the petrochemical industry is located.
Answer: The petrochemical industry is located near Mumbai and Vadodara near the source of the raw material crude oil.

Question 9. What is the use of newsprint? Name two raw materials of the paper industry.
Answer: The paper required for newspapers is called a newsprint. The first newsprint plant was set up at Nepanagar in Madhya Pradesh. West Bengal, Maharashtra and Madhya Pradesh are the leading states in the paper industry. Raw materials required for the paper industry are Bamboo and wood pulp.

Question 10. What are the most important raw materials of the iron and steel industry?
Answer: Iron ore, coal, water and refractories nature.

Question 11. Name the integrated steel plants of India.
Answer: Durgapur, Bhilai, Bokaro, Rourkela, Burnpur, Bhadrawati and Jamshedpur.

Question 12. Name five heavy engineering centres.
Answer: Bangalore, Hyderabad, Durgapur, Bhopal, Naini.

Question 13. Name the automobile centres of India.
Answer: Hindmotor (Kolkata), Premier Automobiles (Mumbai), Maruti Udyog (Gurgaon), DCM Toyota, Surajpur (Uttar Pradesh).

Question 14. Name the steel plants under SAIL.
Answer: Bokaro, Bhilai, Rourkela, Durgapur, VISL and Salem Steel Plant.

Question 15. Name the main centres of textile production in
1. Gujarat and
2. Maharashtra.

Answer:
1. Ahmedabad;
2. Bombay.

Question 16. Where have the four iron and steel plants of India been set up in the post-independence period?
Answer: Durgapur, Rourkela, Bhilai and Bokaro.

Question 17. Name 3 textile manufacturing centres in West Bengal.
Answer:
1. Belgharia.
2. Sleeper
3. Srirampur.

Question 18. Where are the three mini steel plants of India?
Answer: The mini steel plants are at Salem in Tamil Nadu, at Balacheravu in Andhra Pradesh, and at Vijaynagar in Karnataka.

Question 19. What are the uses of petrochemicals?
Answer: The derived petrochemicals are used in the manufacture of various articles such as:

1. Synthetic Fibres
2. Synthetic Rubber
3. Plastics
4. Dye-stuffs
5. Ferrous and Non-ferrous Metals
6. Insecticides
7. Drugs and Pharmaceuticals
8. Synthetic Detergents.

Question 20. What are the raw materials of the cotton textile industry?
Answer: The principal raw materials of the cotton textile industry are
1. Raw cotton.
2. Chemicals (caustic soda, chlorine, bleaching powder, dyes, etc.)
3. Freshwater
4. Electricity.

Question 21. What are the major products of the Bhilai steel plant?
Answer: The plant produces heavy rails, structurals, beams, billets and rolled wire. It produces plates for the shipbuilding industry. The plant also produces by-products like ammonium sulphate, benzol, coal tar and sulphate acid, etc.

Question 22. Define the petrochemical industry.
Answer: These industries are primarily involved in the production of petrochemicals which are derived from petroleum resources. These chemicals are used in the manufacturing of a large variety of articles, such as polymers, (polyethene, polypropylene, polystyrene), synthetic fibres, synthetic rubber, plastics, dye-stuffs, insecticides, drugs, pharmaceuticals and synthetic detergents.

Question 23. Why do most of the petrochemical industrial centres and industrial centres grow in proximity to ports in India?
Answer: The inputs of petrochemical industries are mostly imported & the output is mostly exported. Hence, the availability of the nearest port is a great advantage in the growth of petrochemical industries.

Class 10 Geography WBBSE India – Industries Of India Short notes:

Question 1. Petrochemical industrial complex.
Answer: A petrochemical industrial complex may be defined as an agglomeration of related industries based on the distillation of crude oil into its component chemicals.
Products: Industrial chemicals, explosives, fertilizers, plastics, pesticides, synthetic fibres, paints, medicines and, of course, petroleum products.

Positive effect: It has a positive effect on any economy because of its capital-intensive nature with a cascading interlink among its component units. The flourishing downstream industries bring an economic boom in the regional set-up.
Negative effects: They generate almost limitless gaseous pollutants based on mainly hydrocarbons and nitrogen oxides, some of which are fatal for human life.

In 1984, Bhopal Gas Tragedy killed an estimated 23,000 people by an accidental release of toxic gas.
Examples: Trombay, Thane (Maharashtra), and Haldia (West Bengal).

Question 2. Food processing Industry.
Answer: The industry where agro-based raw materials are used to produce easily usable, attractive and long-lasting food items, is called the food-processing industry. The types of food-processing units found in India are

1. Rice mills,
2. Flout mills,
3. Fruit and vegetable processing units,
4. Soft drinks and aerated drinks,
5. Sugar mills, etc. Food processing is one of the modern concepts of industries in India and is prospering in leaps and bounds.

Class 10 Geography West Bengal Board India – Industries Of India 3 Marks Questions And Answers:

Question 1. What steps have been taken to overcome all the problems of the Indian cotton textile industries?
Answer:
Remedies: Through plans, India’s cotton textile industry is having altogether a new pattern of production.

1. Mills are encouraged to specialise in spinning.
2. Previously mills and handlooms were keenly competitive with each other. But ey are now becoming interdependent.
3. Farmers are encouraged the production of long-staple cotton and high prices are assured to them.
4. Labour problems are tackled with the help of the labour commission.
5. Variety of production to attract foreign markets.

Question 2. Name the iron and steel centres of India.
Answer:
The mainiron and steelcentresofIndia are:

1. TISCO —Jamshedpur (Bihar),
2. Kulti, Burnpur (West Bengal),
3. Durgapur (West Bengal),
4. Rourkela (Orissa),
5. Bhilai (Chhattisgarh),
6. VISL — Bhadravati (Karnataka)
7. Vijaynagar Steel Plant (Karnataka),
8. Salem Steel Plant (Tamil Nadu),
9. Visakhapattanam (Andhra Pradesh)
10. Bokaro —Jharkhand
Besides these, there are 169 mini steel plants and they are producing 31.22 lakh tons of iron and steel.

Class 10 Geography West Bengal Board

Question 3. Name the automobile centres of India. Which is the largest one?
Answer:
Automobile Centres:
1. Hindusthan Motors (Hindmotor) (West Bengal).
2. The Premier Automobile Ltd. (Bombay).
3. Mahindra and Mahindra Ltd. (Bombay and Kolkata).

4. Ashok Leyland Ltd. (Madras).
5. Tata Engineering and Locomotive Co. Ltd. (Bombay and Jamshedpur).
6. Maruti Udyog (Gurgaon).
Hindusthan Motors of Kolkata is the largest automobile centre in India.

Question 4. Name the locomotive-producing centres of India. Which is the largest one?
Answer:
Locomotive Producing Centre:

1. Chittaranjan Locomotive Factory: Producing Diesel, Electric and Stream Engines.
2. Diesel Engine Works: Producing only Diesel Engines, Varanasi: Maruadi, U.P.
3. Tata Locomotives: Producing Narrow Guage Engines.
Chittaranjan is the largest locomotive-producing centre in India.

Question 5. What are the problems of the Iron and Steel industries?
Answer:
(1) Coke coal crisis: Steel plants require good quality coking coal containing 17% ash content. But CIL mines produce coal with 19.1 ash content.
(2) Low rate of capacity utilization: Basic causes for the low rate of capacity utilization include lack of proper maintenance, delay in replacing old parts, managerial problems, bad relations between owner and worker, etc.

(3) Sickness of the mini-steel industry: Storage of key raw materials such as scrap and graphite electrodes and highly inadequate availability of power is the main cause.
(4) Low demand in the International market: Japan produces the best quality steel in the world and India is far behind her. Naturally, Indian steel’s buyers are fewer, only the poor underdeveloped countries.
(5) Capital problem: India doesn’t have plenty of flow capital or finance to construct new Iron and Steel plants or repair and expand the old plants.

Question 6. What raw materials are needed for the cotton textile industry?
Answer: The raw materials needed for the cotton textile industry are:

The principal raw materials for the cotton textile industry are:
(1) raw cotton,
(2) chemicals [caustic soda, chlorine, bleaching powder, dyes, etc.],
(3) fresh water,
(4) power resources [coal, electricity, hydel or thermal, etc.],
(5) machineries,
(6) moist climate.

Class 10 Geography West Bengal Board

Question 7. What is Engineering Industry? What are its divisions?
Answer: The industry which used iron and steel as its main raw material for the production of different types of machinery and other steel goods is called the engineering industry. It can be divided into two categories:

1. Heavy Engineering: These are those engineering industries that produce large and heavy machines for big industries like generators, tractors, and motor vehicles.
2. Light Engineering: The engineering industries that produce delicate machines or machine parts like cameras, radios, typewriters, watches, electrical fans, etc. are called the light Engineering Industry.

Question 8. Why are there so many petrochemical industries in Gujarat?
Answer:
The reasons behind the development of the petrochemical industry in Gujarat are:

1. Availability of crude oil: Gujarat ranks second in the country in the production of crude oil. The main areas of crude oil are the Cambay region, Ankleshwar region, Ahmedabad region, etc.
2. Demand: There is great demand for the products of the petrochemical industry in India and abroad.

3. Development of transport: Gujarat is well-connected with road and railway networks. Gujarat has 40 ports, of which Kandla is a major one.
4. Development of downstream industries: A number of chemical industries and other industries based on the petrochemical industry have come up, which has led to an increase in demand.

Question 9. Not a single jute mill can be found in this region, Ahmedabad Why?
Answer: Ahmedabad region is providing with all other facilities mainly required for the development of the jute industry except raw materials. Raw jute is not produced as the climatic condition is not all suitable for the production of jute.

Jute raw material for the jute industry can be brought from West Bengal by means of Railways and Roadways but the cost of production will go high. So jute industry is not developed here but the cotton textile industry is developed here because of the availability of raw cotton.

Question 10. State the important raw materials of the Petrochemical industry and their occurrence.
Answer:
1. Natural Gas: It is mainly composed of methane, ethane, propane, butane, pentane, hexane and higher hydrocarbons. Natural Gas is found associated with crude oil or non-associated.

Class 10 Geography West Bengal Board

2. Gas from Refinery Operations: Some gas is also produced at various stages in the refinery operations mainly from
(1)The Straight Distillation Units and
(2)Thermal and Catalytic Cracking and Reforming processes.

3. Naptha: It is the most potential raw material for petrochemicals. Naptha is obtained from fertilizer. pants. It is used for the production of
(1)Aromatics: benzene, toluene, zylene and
(2)Synthetic Fibres.

Natural Gas is found in Naharkatiya and Roran oil fields in Assam and Ankleshwar, Kalol and Cambay (Khambat) oilfields in Gujarat. Naptha occurs in the fertiliser plants of Trombay, Gorakhpur, Kota, Chennai, Goa, Kochi, Durgapur, Tuticorin, Mangalore and Barauni.

Question 11. What do you mean by pure and impure raw materials?
Answer:
Pure Raw Materials: Pure raw materials are those whose weight does not reduce in the process of production. E.g-100 kg of raw cotton will yield 100 kg of cotton cloth.
Impure Raw materials: Impure raw materials are those whose weight reduces to a great extent in the process of production. E.g-100 kg of iron ore will not yield 100 kg of pure iron. It will depend on the percentage of iron content in the ore.

Question 12. Give an account of the Salem steel plant in Tamil Nadu.
Answer:
1. Location: This plant is located in Salem in Tamil Nadu. It was commissioned in 1983.
2. Raw Materials: Salem area is rich in iron ore and has easy access to various raw materials. It gets iron ore from the nearby mines of Karnataka and lignite coal from Neyveli.
3. Power & Water Supply: The plant enjoys the facilities of cheap power, charcoal and a vast market.
4. Products: It produces stainless steel, electrical steel and other special types of steel.

Question 13. What are the advantages of petrochemical products?
Answer:
Advantages of Petrochemical Products: Petrochemicals are cost-effective, economically stable, and cheaper as produced on a mass scale. Its. the raw material is easily available, and not dependent on agricultural raw material as in the case of jute. Therefore, traditionally raw materials like wood, glass and metals are being replaced by petrochemical products. For example:

Natural Material Petrochemical Product
1. Leather footwear Plastic chappals and Synthetic footwear.
2. Natural rubber Synthetic rubber.
3. Jute fibre Synthetic fibre.
4. Steel pipes PVC.
5. Steel utensils Plasticware/containers.
6. Cloth and jute bags Polythene bags.

Class 10 Geography West Bengal Board

Question 14. State some causes of the concentration of cotton textile industry in southern India.
Answer: In the southern zone, cotton mills are located in Tamil Nadu, Andhra Pradesh, Kerala, Karnataka and Goa. The causes for their development are :

1. Cotton is easily available in this region.
2. The moist climate favours spinning and weaving.
3. The ports of Chennai, Kochi, New Mangalore, Murmagaon and Tuticorin provide port facilities.
4. People need light cotton clothing.

5. The other favourable factors are:
(1) Cheap hydro-electric power (of Pykara, Mettur and Papnasam),
(2) Local cheap labour and
(3) Facilities for export.

Class 10 Geography West Bengal Board India – Industries Of India 5 Marks Questions And Answers:

Question 1. Explain the major factors responsible for the development of the Iron and Steel industry in Eastern and Central India.
Answer:
Factors responsible for the development of the Iron and Steel Industry: Most of the iron and steel plants of India, such as Jamshedpur, Burnpur, Durgapur, Rourkela, Bhilai and Bokaro are located in Jharkhand, West Bengal, Odisha and Chattisgarh. The causes for the concentration of iron and steel plants in eastern India are:

1. Iron ore: About 80% of India’s iron ore is available in this region. The major mines are
(1) Noamundi, Guwa, Budaburu, Pansiraburu of Singhbhum district, Jharkhand,
(2) Gurumahishani, Badampahar, Sulaipat and Bonai of Mayurbhanj district and Bagiyaburu of Keonijhar district, Odisha.

2. Coal: About 97% of India’s coal is mined in this region. The steel plants of Kulti, Burnpur, and Durgapur get their coal from the mines in Raniganj and Asansol. The steel plants of Jamshedpur, Bokaro and Rourkela get their coal from Jharia, Bokaro, Ramgarh and Giridih in Jharkhand.
3. Other raw materials: Limestone, dolomite, manganese, etc. are collected from Kalahandi, Gangapur and Kara put of Odisha. Other raw materials like chromium, tungsten, nickel, etc. are easily collected from the Chotanagpur plateau.

4. Water: The rivers Damodar, Mahanandi, Subarnarekha, etc. supply ample water required in the steel plants.
5. Transport: The network of roadways and railways in eastern India help in trade and commerce. The ports at Kolkata, Haldia and Paradweep help in international trade.
6. Power Supply: Thermal power is acquired from Bokaro and Durgapur thermal power plants. Hydel power is acquired from power projects at Hirakud, Myth, Panchet and Tilaiya.

Question 2. Mention the geographical factors responsible for the growth of iron and steel industry in West Bengal.
Answer: The geographical factors responsible for the growth of iron and steel industry in West Bengal are:

1. Durgapur Steel Plant and Indian Iron & Steel Company, Kulti-Burnpur are very close to the coking coal mines at Raniganj, Asansol and Jharia.
2. iron-ore is brought from Bonai, Keonjhar, and Sulaipat to the steel plants, which are not very far away from these plants.

3. Ferro-alloys like manganese can be brought from Orissa by means of railway wagons in lieu of sending coal there which is minimising the carrying cost.
4. Availability of clear water and cheap hydel and thermal power from Damodar Valley Corporation.

5. Closeness to the vast market of Kolkata and its surrounding is another factor.
6. Nearest port facility is another factor.
7. Availability of cheap labour is another factor. The state is densely populated, so there is a steady supply of cheap labour.

Geography Class 10 Solutions WBBSE

Question 3. Name the raw materials mainly required for the development of iron and steel industry.
Answer:
Raw materials needed for iron and steel industry are:

1. Iron ore is the most important and basic raw material for the iron and steel industry.
2. Fuels: The important fuels are coal and coke. Modern blast furnaces use coke. Many iron and steel plants even today use charcoal (Bhadrawati).

3. Flux (Limestone & Dolomite): Flux is used in the blast furnace to draw impurities out. Limestone and dolomite are mixed with the extracted impurities to form slag.
4. Refractories: Both blast and steel furnaces are lined with refractories. Refractories are used for lining furnaces for smelting iron ore. It is also used for the lining of the furnaces of locomotives, and boilers and for making fire bricks.

5. Silica or sand is used in the iron and steel plant for moulding. A huge quantity of sand is needed for moulding purposes.
6. Water: Water is an important raw material for the iron and steel industry. It is mainly used for quenching coke, cooling blast furnaces, making steam, cooling furnace doors, operating hydraulic machinery and to have sewage disposal.

7. Air: Air is an important item for the iron and steel industry. Near about 4 tonnes of air are needed to make one tonne of steel.
8. Ferro-Alloys: For the production of steel of different grades, various non-ferrous metals like aluminium, chromium, cobalt, copper, lead, etc. are used. Among the ferroalloys, manganese is widely used in the industry.
9. Electricity: Cheap electricity is required for the iron and steel industry. Hydel, thermal and atomic powers are needed for the production of iron and steel.

Question 4. Why is Ahmedabad called the Manchester of India?
Answer: Ahmedabad is known as the Manchester of India because it has many similarities with Manchester in the development of the cotton textile Industry. Manchester, situated on the bank of river Marshey behind the port Liverpool, is the largest textile centre in the U.K.

Favourable factors for the development of the textile industry in Manchester:
(1) It imports long-staple cotton from Egypt and other countries.
(2) Temperate climate is suitable for spinning fibre thread.
(3) Coal is obtained from the Pennine range nearby.
(4) Water of the river Marshey is good for dying thread.
(5) Textile machinery is locally manufactured.
(6) The products have a worldwide market.
Like Manchester, Ahmedabad is situated on the bank of river Sabarmati near the Kandla port.

Favourable factors of the development of textile industries in Ahmedabad:
(1) The black soil is suitable for the production of long-staple cotton. It is also imported from foreign countries through the ports of Kandla and Mumbai.
(2) Cotton textile machinery are locally produced and can be easily imported.
(3) The water of Sabarmati is good for dying thread.
(4) The temperate climate is also good for spinning fine thread.
(5) The products have a huge demand inside and outside India.
(6) Cheap labour is obtained from the neighbouring areas.
All these factors have made this centre as the greatest textile centre of India.

Geography Class 10 Solutions WBBSE

Question 5. What are the factors responsible for the concentration of the Iron and Steel industry in eastern and central India?
Answer:
The factors responsible for the concentration of Iron and Steel industry in eastern and central India are as follows:

1. Availability of Iron ore: High-graded iron ores are available in Singbhum district of Jharkhand, Mayurbhanj, Bonai and Sundargarh district of Orissa, and Dhalli-Rajhara of Durg district, Bailadila of Bastar district of Chhattisgarh. It determines the location of Iron and Steel plants in East and Central India.

2. Availability of Coal: Like iron ores, coal is essential for Iron and Steel plants. Jharia coal field of Jnarkand supplies high-quality coal. Coal fields are also located in the East-Central parts of India such as Raniganj, Bokaro, Giridih, Korba, Talcher, etc. It is one of the most important factors causing this concentration.

3. Concentration of the other raw materials: Other raw materials for Iron and Steel plants are manganese, limestone, dolomite, water and others. They are also available in the Eastern-Central parts of the country. It also encourages its development.
4. Port facilities: The ports of Kolkata, Vishakhapatnam, etc. provide port facilities for importing machinery for the industries and exporting finished products.

5. Ready market: The central and western parts of India provide a ready market for the iron and steel produced. The dense population and the industrial belts of the Hooghly Industrial Region, Asansol-Durgapur Industrial Region, and Jamshedpur-Muri Industrial Regions have a high demand for iron and steel.

6. Other factors for the development of this industry are
(1) Availability of water from rivers,
(2) Transport facilities of roadways and network of railways,
(3) availability of cheap industrial labour.

Question 6. Justify the concentration of the cotton textile industry in the black soil region of Western India.
Answer: The reasons for the concentration of the cotton textile industry are as follows:

1. Raw materials: Lava region is situated near Mumbai. This region is famous for black cotton soil and by rail and road transport cotton is collected at the industrial units. Ahmedabad is situated in the heart of the cotton-growing area of Gujarat.
2. Rail: road transport system is highly developed through Thalghat and Bhorghat (for Mumbai) for the transportation of raw materials as well as finished products.

3. Mumbai has excellent harbour facilities for importing long-staple cotton and machinery for the mills and exporting the finished products.
4. Cheap hydel power is available in Mumbai while the Sabarmati river supplies soft water for dyeing and bleaching, etc.
5. Humid climate is favourable for spinning and weaving in both regions.
6. Bombay & Ahmedabad both are connected by roads and railways with every part of the country.

7. There are good markets both home and foreign for the yarn and fabrics.
8. There is a supply of skilled and unskilled workers in large numbers.
9. Chemical industries are well-developed in Mumbai, Ahmedabad and Pune regions.

Geography Class 10 Solutions WBBSE

Question 7. Analyse the locational advantages of any one Iron and Steel industrial centre of India under the public sector.
Answer: The steel plant is situated in the district of Burdwan in West Bengal. It was set up in the second five-year plan period with the collaboration of ISCON (a British firm). It started production in 1962.

1. Iron ore is obtained from Singhbhum (Jharkhand) and Keonjhar (Orissa).
2. Coking coal is obtained from Ranigunj, Jharia and Barakar.
3. Manganese from Barbil, Jamdar and Bonai (Orissa).
4. Limestone and Dolomite from Birmitrapur (Orissa) and Hathibari.
5. Situated on the bank of the Damodar river, it gets water from the river of adjoining state.
6. Cheap and skilled labour is available from the agricultural and mining regions of adjoining states.
7. Calcutta, at a distance of (175 km) provides market-cum-port facilities.
8. The centre is situated on the Eastern Railway and National Highway No 2. Hence the transport facility is available.
9. Hydel power from D.V.C. and thermal power from Santhaldih and Bokaro are easily available.

Question 8. Explain why Durgapur, Rourkela and Bhilai have been selected as centres of the iron and steel industry.
Answer:
Durgapur: Durgapur has been selected as a centre of iron and steel manufacturing for the following reasons:

1. The coal mines of Raniganj, Asansol, etc. are close by.
2. Iron ore, limestone & manganese can be brought by empty wagons coming from Bihar and Orissa to carry coal there.
3. Availability of water and power from D.C.
4. Labour is available in plenty.
5. It is connected with the market. and port of Kolkata by rail and road, the distance is only 160 km.

Rourkela: Rourkela is situated on the left bank of the Brahmani river in Orissa. It has been selected as a centre of iron and steel industry for the following reasons:

1. A large supply of iron ore is available within a distance of 50 km in the state of Orissa.
2. The coal belt of Bihar and West Bengal are close by. The wagons which carry iron ore from Orissa to Burnpur and Durgapur return to Rourkela with coking coal from Jharia.
3. Cheap labour is available.
4. It is connected by railways with important ports like Kolkata, Madras, Visakhapatnam and Paradeep.

Bhilai: Bhilai is situated in Chhattisgarh. It has been selected as an iron and steel manufacturing centre for the following reasons:

1. Iron ore is available from the Dalli-Rajhara mines (32 km) in Madhya Pradesh.
2. Cialis are available here at Korba and more can be easily brought from the state of Bihar also.
3. Cheap labour is available.
4. Manganese and limestone are available in large quantities.
5. It is connected with important cities of central India and also Kolkata and Mumbai by railways.

Question 9. What are the prospects of the Indian Iron and Steel Industry?
Answer: India possesses a large potential for the development of the Iron and Steel Industry. India enjoys a substantial comparative cost advantage even with respect to the steel industries of advanced countries like Japan and Germany.

1. Basic raw materials like iron ore, coal (coke), limestone, dolomite, manganese ore and other ferroalloys, and refractory materials are available in India. India has a large human resource of scientists and engineers. Labour cost is also one of the lowest in the world.

2. The industry has acquired a high degree of technological self-reliance. Considerable expertise in planning, detailed engineering, machine-making, etc. has been built up in institutions like the Metallurgical and Engineering Consultants (India) Limited (MECON). A research and development unit has been set up under SAIL. These measures will help the steel industry to reduce production. cost and improve the quality of production in near future.

3. Industrialisation programmes in the second and subsequent plans and the consequent industrial revolution through the growth of capital goods industry, capital consumer goods industry and consumer goods industry have created a ready domestic
the market for iron and steel.

4. The strength of the Indian steel industry is to be judged by its export success which is already commendable.
5. The functional autonomy granted to SAIL is a good move for achieving a high degree of capacity utilisation in all plants in the public sector. In TISCO, technological updating has been taken up as a continuous process which is really the secret of Tata Steel’s remarkable success.
6. Today electrical furnace units and the mini steel plants, as they are called, are providing 30% of the total steel supply. There are 169 mini-steel plants already in operation.
7. Certain measures like the privatisation of industries have been taken to improve the operational efficiency of the steel plants.

Geography Class 10 Solutions WBBSE

Question 10. Give an account of the growth and development of the Cotton Textile Industry in India.
Answer:
Growth of Cotton Textile Industry in India: The foundation of modern industry in India was laid with the development of the cotton textile industry in the second half of the 19th century. Even today the cotton textile industry is the backbone of our economy. About 9.5 lakh workers or about 2.6 per cent of industrial labour in India is engaged in the cotton textile industry. It is the main foreign exchange earning industry. It also supports a number of other industries – dyes, chemicals, mills, stores, packing material and the handloom industry.

The growth of the Indian cotton industry took place in two stages. In the first stage, mills were largely concentrated in Bombay and in the nearby areas. A Parsee industrialist started the cotton factory at Bombay in 1851. From that time up to the First World War (1914), the cotton textile industry rapidly developed around Bombay.

The main factor for the development of the industry was located around a natural port. This helped to export the yarn to the huge markets of China and Japan, and also import machinery and coal from Britain and South Africa. The nearby cotton growing areas supplied the raw material. Progress was so rapid that in about 50 years’ time about 80 cotton mills were located in Bombay and in its nearby areas. In the second stage of growth of the textile industry, factories were located interior of the country and away from the cotton growing areas. This was because:

(1) At the beginning of this century, Japan also developed her industry very rapidly. She started competing with India. India not only lost her market in China and Japan, but Japanese goods started flooding the Indian market. To capture the local market, therefore, _ industry shifted to the interior, especially in the northern and eastern parts of the country.
(2) Development of railways also helped the industry to shift to the interior, especially near the cotton growing areas. Ahmedabad, Nagpur, Baroda, Sholapur, and Broach developed the industry.

(3) Development of hydro-electricity in South India, Punjab and western parts of Uttar Pradesh also helped in the rapid development of
the industry.
(4) High labour wages, more taxes, high-cost maintenance around Bombay also forced the industry to move towards different areas where cheap labour, low rent of land, power and coal, etc. offered many facilities for industry
(5) During the Second World War there was a considerable rise in military demand
(6) Also the impact of the Swadeshi movement had also a stimulating effect on the development of the textile industry in the country.

By the end of 1974, there were 691 mills (403 spinning and 288 composites) spread in different parts of the country in about 75 towns. However, more than 374 of the mills are distributed in four zones
(1) The Western zone,
(2) The Southern zone,
(3) The Eastern zone and
(4) The Northern Zone.
India’s cotton Textile Production

Year	Production	Year	Production
1951	4210	1971	7602
1961	6738	1981	8368

Question 11. Describe the cotton textile mills of the Eastern Zone and the Northern Zone in India.
Answer:
The Eastern Zone: The industry is mostly developed in the Hooghly basin. Demand for cotton cloth is the main factor for the development of the industry. Cotton is mostly imported from Egypt and Sudan. Coal is available from Raniganj.

Calcutta is already an industrial and very densely populated city. Skilled and cheap labour is, therefore, easily available. A network of excellent roads, railways and many rivers connects the industry with the nearby towns, villages and cities which provide a ready market. The cotton industry here specialises in the production of coarse, grey and bleached cloth.

The Northern Zone: Some factories are also developed at various places in Uttar Pradesh, Punjab, Haryana and Delhi. Important centres here are Kanpur (17 mills), Lucknow, Agra, Aligarh, Bareilly, Meerut, Ludhiana and Amritsar. The dense population also provides necessary markets and cheap labour and irrigated areas in Uttar Pradesh and Punjab provide cotton. Local, as well as imported cotton, is used.

Kanpur with 17 mills is the main cotton textile centre in the north. It is located on the bank of the river Ganges which provides water for washing, bleaching and dyeing. The cotton is available from nearby irrigated areas. Imported cotton is also used. Coal comes from the nearby state of Bihar (Jharia coal fields). Kanpur specialises in khaki cloth and cloth for tents.

Geography Class 10 Solutions WBBSE

Question 12. Explain the pattern of distribution of engineering industries in India.
Answer:
The pattern of Distribution of Engineering Industries in India: The growth of the engineering industry in India is noted mostly after independence. This industry is developed mainly to change the basis of the economy from agriculture to industry and also to be free from importing machinery from outside.

Various factories are set up to design, build and fabricate a wide variety of machines and equipment from light to heavy engineering goods. India at present manufactures industrial, electrical and agricultural equipment. The various factories are controlled by both private and public sectors.

On the whole, the location of engineering industries is influenced by various factors- power, skilled labour – fitters, turners, engineers, etc. and entrepreneurship rather than raw materials. The industry. gains considerably from agglomeration economies and hence various units-+;e clustered near one another. More concentration of factories and foundries noticed in the iron and steel industry near coal mines and hydel-power sites and big urban centres where skilled hours ud other factors are available.

The main public sector units, however, give the idea of the foot-loose nature of the industry. To bring about balanced growth of industrial units in various areas is the main concern of public engineering units. Heavy Engineering factories are located at Ranchi, Naini (Allahabad), Tungabhadra (Karnataka) and Visakhapatnam. Thus various plants manufacture complex steel structures: building structures, power-transmission towers, pressure vessels, cranes, ropeways, and equipment for petrochemicals, heavy chemicals and allied industries.

Light Mechanical industries are located near the main industrial centres of India-Hooghly basin, Bombay-Pune region, Delhi-Gaziabad region, Bangalore – Hyderabad region, Vadodra, etc. Various items like bicycles, ball and roller bearings, alarm timepieces, agricultural implements, tractors, etc. are manufactured here.

Heavy electrical industry centres are located at Bhopal [Heavy Electrical (India) Ltd.], Haridwar [Heavy Electrical Equipment Plant], Tiruchirapalli (Heavy Power Equipment Plant), Rama Chandrapuram (Hyderabad), Rupnarayanpur in West Bengal. The above units manufacture large AC and DC motors and Switchgear, generators, Power transformers, water and steam turbines and power cables (Rupnarayanpur).

The various precision instruments, survey instruments Factory, Calcutta, Ophthalmic blanks and lenses are made at the Ophthalmic Glass project at Durgapur. X-ray and electro-medical instruments are manufactured at Bharat Electronics Ltd., Jallhalli (Bangalore). Production of scientific surveying, optical and mathematical instruments went up from Rs. 2.3 crores in 1971 to Rs. 3.3 crores in 1974.

Progress made by the engineering industry is remarkable. Thus the output of light and medium industries increased from Rs. 50 crores in 1950-51 to Rs. 3600 crores is 1974-75. Export of engineering goods in 1974-75 touched an all-time record of Rs. 312 crores as against only 6 crores in 1950-51. The very important and encouraging feature of our exports is that various engineering goods are not only in demand in the developing countries but there is noticed a very rapid increase in demand even in the most developed countries like the U.K., France, U.S.And Germany.

Question 13. Why is Durgapur called the Ruhr of India?
Answer:
Durgapur is called the Ruhr of India because of the following reasons: The plant is situated on the bank of the river Damodar 15 km away from the Kolkata Delhi Railway route.
It gets raw materials:

1. iron ore is obtained from the Bonani mines of Orissa.
2. Coal from Jharia and Barakar fields.
3. Limestone is obtained from Birmitrapur and Hathibari areas.
4. Water is obtained from the Damodar river.
5. Manganese from Jamdar of Bonai.
6. Electricity from DV.C., Santalidh, Bokaro thermal and hydel power stations.
7. Kolkata port is only 175 km away from this region which can be easily reached by national highway and railways—South-eastern and Eastern.
8. Cheap and skilled labour is obtained from the densely populated mining and agriculture belt.
9. Wide market of West Bengal and its adjoining states.

10. Well-developed transport and communication by means of roadways, railways and waterways. All these factors have favoured the growth of an iron and steel centre in al Durgapur, along with other allied industries. Durgapur Iron and Steel Centre has a similarity with the Ruhr region of West Romanies.

Ruth valley is also developed in the field of iron and steel and allied industries. Coal from the neighbouring region, iron-ore from Sweden, water from the “er Ruhr, a well-suited climate for hard-working, labour’s wide market, Rhine-Ruhr Waterway along with roadways and railways, wide market inside and outside the Country. Humberg port facility labourers, etc. have favoured the growth of iron and Steel industries along with other allied industries. As it has a similarity with Durgapur Gf India, Durgapur is called the Ruhr of India.

Question 14. Give a short account of the Bhadrabati Steel plant.
Answer:
Bhadrabati Steel Plant: The Steel Plant at Bhadrabati has changed its name from Mysore Iron and Steel Company (MISC) to Visweshwarya Iron and Steel Limited (VISL). It is situated on the Bhadra river in Karnataka. It derives:

1. Iron ore supply from Kemangunidi mines on the Bababudan hills to the south.
2. Charcoal (as coal is not available nearby) from the Shimoga Kadur forests to the east.
3. Cheap and abundant hydel power from Jog Falls to the northwest.
4. Plenty of water from the Bhadra reservoir to the southwest.
5. Manganese from Shimoga and Chitradurga districts and Limestone from Bhandigunda district to the northwest.
With the depletion of forests, the plant no longer depends on Charcoal. Instead, it brings coking coal from Korba and uses cheap hydel power to produce special types of high-value steel.

WBBSE Class 10 Geography Chapter 5 Question Answer

Question 15. What are the raw materials needed for the iron and steel industry? What are the geographical factors responsible for the growth of this industry in West Bengal Where is the biggest iron and steel factory in India located?
Answer: The chief raw materials for manufacturing pig blast furnaces are iron ore, coke and limestone. A modern blast furnace requires more than 1 lakh ft. of air to produce only 1 ton of iron. Steel is made by reheating pig iron in converters to remove the impurities and adding carbon and various ferro-alloys such as manganese, vanadium, chromium, cobalt, nickel, tungsten, etc.

The geographical factors responsible for the growth of the iron and steel industry in West Bengal are:
1. The plants of Durgapur, Burnpur, and Kulti are very close to the coking coal mines at Raniganj, Asansol and Jharia.
2. Iron ore, limestone, manganese and other ferro-alloys can be brought very cheaply by railway wagons coming from Bihar and Orissa to carry coal there, which otherwise would have returned empty.
3. Availability of plenty of water and power of D.V.C.
4. Closeness (about 160 km) to the vast market of Kolkata and to the port.
5. Availability of cheap labour.
The biggest iron and steel factory of India is being set up at Bokaro, Bihar.

Question 16. What are the problems faced by the cotton textile industries in India?
Answer:
The cotton textile industry suffers from the following problems:

1. Shortage of Raw Material: There is a shortage of raw material, particularly of long-staple cotton, which is imported from Pakistan, Kenya, Uganda, Sudan, Egypt, the USA and Peru.

2. Sick Industrial Units: The cotton industry faces the constant threat of sickness and consequent closure, because of
(1) Uncertainty of raw material.
(2) low productivity of machines and labour.
(3) Increasing competition from the power loom sector.
(4) Lack of modernisation and
(5) management problems. These sick units require heavy financial investments for replacement and modernisation purposes. Many of these
sick units have been taken over by the government.

3. Loss of Foreign Markets: The Indian cotton textile industry has lost some of the foreign markets due to production and the development of the cotton textile industry a number of Asian countries like China and Japan and African countries. The Indian cotton textile goods face stiff competition in foreign markets from Taiwan, South Korea and Japan whose goods are cheaper and better in quality. i

4. Inadequate Production: The cotton textile industry faces inadequate production because of the lack of adequate and unfailing power supply and also because of competition with the decentralised sector. Thus she has to face stiff competition! On from other Asian countries.
5. Shortage of Power: The cotton textile mills are facing an acute shortage of power. Supplies of coal are difficult to obtain and frequent cuts in electricity and load-shedding affect the industry badly. This leads to loss of man hours, low production and loss in the mills.

WBBSE Class 10 Geography Chapter 5 Question Answer

6. Obsolete Machinery: In India, most of the cotton textile mills are working with old and obsolete machinery. According to an estimate, in India over 60 per cent of the spindles are more than 30 years old. The automatic looms account for only 18 per cent of the total number of looms in the country against the world average of 62 per cent and 100 per cent in the United States. Obsolete machinery results in low output and poor quality of goods as a result of which Indian textile goods are not able to face competition in the international market.

Question 17. Give an account of the major IT sector in India.
Answer: India is the world’s largest outsourcing destination for the IT industry. The industry employs about 10 million Indians and contributes significantly to the social and economic transformation in the country. It energises the higher education sector, especially in engineering and computer science. The Indian IT industry is divided into four major segments

1. IT services,
2. Business process management,
3. Software products and engineering services,
4. Hardware. Indian IT’s core competencies and strengths have placed it on the international canvas, attracting investments from major countries.
E.g: The software and hardware industry attracted $ 13,788.56 million between April 2000 and December 2014. The main centres of IT in India are — Bangalore, Hyderabad, Chennai, Kolkata, Mumbai, Delhi, etc. Bangalore and its surrounding region is known as silicon valley due to the presence of numerous IT centres.

Question 18. State the factors for the growth of IT sector in India.
Answer:
Factors for the Growth of It sector in India: This industry has flourished in India because of certain factors:

1. The Government of India has started the ‘Digital India’ project which has given IT a secured position inside and outside India.
2. The IT sector in India is generating 2.5 million direct employment. So, India has become one of the biggest IT capitals of the modern world.
3. Bengaluru is considered to be the Silicon Valley of India because it is the leading IT exporter. Exports dominate the industry and constitute about 77% of total industry revenue.
4. India provides a large domestic market for this industry.
5. The top 5 Indian IT Service Providers are Tata Consultancy Services, Infosys, Cognizant, Wipro and HCL Technologies.
6. The Software Technology Parks of India (STPI) is owned by the government. These parks in different cities provide satellite links to be used by firms.
7. The government also allowed individual companies to have their own dedicated links which allowed work done in India to be transmitted abroad directly.
8. A number of cities in India are developing IT infrastructure and are taking part in software exports.
9. Indian Institute of Information Technology is set up to create a pool of technically literate individuals for its growing industry.
10. High concentration of IT companies and quality research and development institutions throughout India also contribute to its growth.

Question 19. Give an account of Union Carbide India Ltd.
Answer:
Union Carbide India Ltd. (UCIL): This petrochemical plant was founded at Trombay (near Mumbai) in Maharashtra under the organisation of a multinational company. UCIL has a capacity of 60,000 tonnes of Naptha crackers.

Petrochemical Products: Under full capacity, UCIL can produce 11,000 tonnes of products—Polythelene, Butyl alcohol, Acetic acid, Ethyl acetate, Ethyl hexanal and Dioctyl phthalate.

Some Important End-Products of UCIL:
1. Films for Packaging,
2. Bags as hold-all,
3. Squeeze Bottles of various sizes and shapes,
4. Carboys for industrial chemicals and other industrial containers,
5. Insulation for electric wires and cables,
6. Pipes for carrying drinking water,
7. Tarpaulins,
8. Godown covers,
9. Films,
10. Canal lining,
11. PVC, etc.

Facilities for Plant Location of UCIL:
1. Raw materials are easily available from the local oil refineries at Trombay and Mumbai (erstwhile Bombay)
2. Products are quickly ported from the plant through Pipelines, Roadways and Railways.

3. Huge financing from multinational companies has enhanced the introduction of Modern Technology in the plant complex of UCIL;
4. Heavy demand of petrochemical products in the industrial units of the Mumbai-Pune Industrial Belt.
5. Hydel power supply from the projects of the Western Ghat region.

Question 20. Give an account of Haldia Petrochemicals Ltd.
Answer:
Haldia Petrochemicals Limited (HPL): HPL is a Joint Venture, promoted by West Bengal Industrial Development Corporation (WBIDC), Chatterjee Petrochem (Mauritius) Company of Chatterjee Group and ‘Tatas’ represented by TELCO and Tata Electric Companies. The groundbreaking, to commence construction of the Units under the HPL complex, took place in April 1997. This project of worth Rs. 5170 crores was inaugurated on 2 April, 2000.

The Rs. 1,6000 crores Mitsubishi Chemical Corporation promoted the purified terephthalic acid (PTA) project in Haldia was inaugurated on 11 April 2000, nine days after the commissioning of HPL. The locational advantages in and around Haldia are immense at the present time.

1. Haldia Dock Complex will be of unique help for the rapid progress in HPL performance.
2. HPL is situated within the Haldia Industrial Belt.
3. This Industrial town is devoid of infrastructural hazards.

4. The refinery at Haldia will always be assisting with necessary raw materials in abundance to its in-door petrochemical complex.
5. Transport network through railways, roadways, inland waterways and offshore sea routes is now well-knit with the HPL’s industrial point.
6. Power for this will be an uninterrupted energiser for HPL.

WBBSE Class 10 Geography Chapter 5 Question Answer

Question 21. Discuss the automobile industry in India and the reasons for its growth.
Answer:
Automobile Industry: Before independence, there was, in fact, no automobile industry in India; only assembly works were done from imported parts. The real beginning started with the establishment of Premier Automobiles Ltd. at Kurla (Mumbai) in 1947 and Hindustan Motors Ltd. at Uttarpara (Kolkata) in 1948.

Today, the automobile industry is a rapidly growing industry in India. Mumbai, Chennai, Jamshedpur, Jabalpur and Kolkata are the major centres for producing automobiles. All sorts of vehicles are produced in these centres. Maruti Udyog Ltd. (MUL) of Gurgaon in Haryana started the production of passenger cars in 1983.

It manufactures about 77 per cent of such vehicles are produced in India. Various types of automobiles, scooters, jeeps and vehicles are also manufactured at several places in the country, such as, Lucknow, Pune, Mumbai, Kanpur, Ennore, Chennai, Faridabad, Hyderabad, Kolhapur, Tirupati, New Delhi and Alwar (Rajasthan).

The causes of the development of this industry are as follows:
1. Steel is the basic raw material for this industry ancillary industries have developed near places producing tyres, tubes, storage batteries, etc.
2. Port cities like Mumbai, Chennai, etc. offer import and export of finished goods.
3. The industry in recent years has become market-oriented.
4. Capital investment in large amounts is easily obtained from Metropolitan cities like Mumbai, Chennai, Delhi and Kolkata.

Question 22. Give an account of the petrochemical industry in India.
Answer:
Petrochemical Industry: Petrochemicals are essentially chemicals and compounds derived from petroleum resources. These chemicals are used in the manufacture of a wide variety of articles, such as synthetic fibres, plastic, ferrous and non-ferrous metals, synthetic rubber, dye-stuffs, insecticides, drugs and pharmaceuticals and synthetic detergents.

The products from the petrochemical industry have entered every aspect of human activity. In India, the petrochemical industry is of recent growth The demand for products from the petrochemical industry has been rising rapidly in the country. The industry, therefore, has to expand its capacity to meet the growing demand. The important raw materials necessary for the petrochemical industry are Naptha, natural gas and refinery gas.

The first petrochemical complex was established by Union Carbide India Ltd. at Trombay in 1966. National Organic Chemical Industries Ltd. was set up in 1968 at Thane. The Index Plant at Kayali Refinery for the production of benzene and toluene was commissioned in 1969. IPCL’s mega petrochemical complex at Vadodara (largest government petrochemical industry in India) was commissioned in 1973 and the

Olefin complex was ae in IPCL has an up = Olefin complex at Nagothane in Maharashtra. The third such complex has been set up at Gandhar in
Gujarat. Jamnagar of Gujarat is the largest private petrochemical industry. Petrofils Corporation Ltd. (PCL) is a joint sector company of the Govt. of India and Weavers’ Co-operative Societies.

WBBSE Class 10 Geography Chapter 5 Question Answer

It manufactures polyester filament yarn and nylon filament yarn at its three units located at Vadodara and Naldhari in Gujarat. The Bongaigaon Petrochemicals Ltd. is set up at Bongaigaon as an adjunct to the Bongaigaon refinery. This complex manufactures polyester fibre and ortho-xylene.

There has been a steady increase in the consumption of major petrochemical products in India in recent years. To meet the growing demand, the Government has sanctioned several petrochemical complexes in the public and private sectors. As a result, petrochemical projects are being implemented at Hazira, Jamnagar and Bharuch in Gujarat, Chennai in Tamil Nadu, Mangalore in Karnataka, Vishakhapatnam in Andhra Pradesh, Haldia in West Bengal and Auraiya in Uttar Pradesh.

In 2000-2001, India produced 3441 thousand tonnes of polymers, 1,567 thousand tonnes of synthetic fibres, 55,000 tonnes of synthetic rubber and 359 thousand tonnes of synthetic detergents. The petrochemical industry now contributes 14% of the production of the entire manufacturing sector and its share in export is also 14%.

Question 23. Explain the distribution of cotton textile industries in India.
Answer:
Distribution of Cotton Textile Industries in India: Indian monopoly in the manufacturing of cotton textiles is very old. The first modern cotton mill was set up at Ghushuri (Fort Glaster) near Kolkata. But that mill stopped functioning within a short period for want of raw cotton supply. The first successful modern cotton textile mill was established in Mumbai in 1854.

Today cotton textile is the largest industry of India. It gives employment to over 15% of all factory labour. It supports a large number of industries like chemicals, packaging materials and engineering works. Textile exports account for over 1/10th of the total value of export from the country. The cotton textile industry in India is divided into two sectors — the mill sector and the decentralised sector (power loom and handloom). Today 93% of the cotton cloth is produced in the decentralised sector.

In the early years of the cotton textile industry, most of the mills were located in Maharashtra and Gujarat. Availability of raw cotton, market, humid climate, cheap labour and transport facilities in these areas contributed towards its localisation. Today, the cotton textile mills are spread over 80 towns and cities of India, but most of them are concentrated in Maharashtra, Gujarat, West Bengal, Uttar Pradesh, Madhya Pradesh and Tamil Nadu.

Maharashtra is the largest producer of cotton textiles. Mumbai is the largest centre with 63 mills out of Maharashtra’s total of 122 mills. Mumbai is called the cotton polos of India. Other important centres of Maharashtra are Solapur, Pune, Kolhapur, Satara, Wardha, Nagpur, Aurangabad, Amravati and Jalgaon.

Gujarat has 125 cotton mills. Ahmedabad is the largest centre where 73 out of 118 mills of Gujarat are located. The city is called the Manchester of India. Other important centres of a cotton mills in this state are Vadodara, Surat, Rajkot, Porbandar, Maurvi, Bhavnagar, etc.

In Madhya Pradesh cotton is grown and coal provides the necessary energy. Abundant cheap labour is available. Gwalior, Ujjain, Indore, Jabalpur, Bhopal, etc. are important centres. Among the southern states Tamil Nadu is the most important cotton textile producer. Coimbatore is the most important centre and is known as the Manchester of South India. Other important centres are Chennai, Madurai, Tirunelveli, Salem, Perambur, Tuticorin, etc. Other important centres of a cotton mill in the southern zone are Bangalore, Hubli, and Mysore in Karnataka, Thiruvananthapuram, Alleppey and Trichur in Kerala, Hyderabad, Vijaywada, Guntur in Andhra Pradesh, Pondicherry and Goa.

In the Eastern zone, some cotton mills are found in West Bengal, Jharkhand, Orissa and Bihar. In the Northern zone, some cotton mills are developed in Uttar Pradesh (Kanpur, Lucknow, Aligarh, Agra, Bareilly, Meerut), Punjab (Amritsar Ludhiana, Phagwara), Haryana (Bhiwani, Hissar, Rohtak), Rajasthan (Pali, Bhilwara, Udaipur, Jaipur, Ajmer) and Delhi.

Class 10 Geography West Bengal Board

Question 24. Describe the factors that influence the location of industries.
Answer: Industries concentrate in certain areas which become centres of industrial activity.
The infrastructure of an industry depends on the following:

Geographical factors: These include raw materials, power supply, water, transport, labour, market, site and climate.
Commercial factors: These include capital, bank and credit facilities, Government policies and organisational efficiency.

Geographical Factors:
1. Raw Materials: The decision regarding the location of a particular industrial activity is guided by the availability of raw materials in a particular area. The earliest industries in India developed near the sources of raw material. For example, the textile mills of Mumbai received the supply of cotton from Gujarat and the jute mills of the Hooghly region got raw material from the deltaic region of the Ganga. Similarly, the iron and steel industry is located in the region where iron ore, limestone, manganese and coal are available.

The availability of raw materials nearby reduces the cost of transportation. The nature of raw materials also decides the location of industries. For example, perishable raw materials have to be processed without loss of time before manufacturing. That is why sugar mills are located in areas of sugarcane production.

2. Water Supply: Water is required for the development of industries as it is needed in the process of manufacturing, cleaning, cooling, washing, etc. All industries depend heavily on the availability of water for one purpose or the other. These include iron and steel (for cooling), textiles (for bleaching and washing), paper and pulp, chemicals, food processing, jute, leather, nuclear power, etc. Therefore, these industrial units are located at places where water is easily available.

3. Energy: Energy is required to process raw materials into manufactured goods. That is why the iron and steel industry is usually located near the coal resources, as it uses coking coal for fuel. Similarly, the electro-metallurgical and electro-chemical industries which require power are located where electricity is easily available. In the coal-deficient peninsular region, industries could develop by using hydel power instead of thermal power. Thus, the availability of energy in one form or the other is an important factor in deciding the location of a particular industry.

4. Transport: Transport is an essential pre-requisite for industrial development as transport facilities are required to carry raw materials to manufacturing units and finished products to the market. The availability of transport facilities has led to the development of industries near the port towns that are linked with rail and road to the hinterland.

5. Labour: The availability of both skilled and unskilled manpower is an important factor in the location of industries. The mobility of labour is also a significant factor. It is because of the mobility of cheap labour from the surrounding areas to Delhi and Mumbai, that a large number of industries are located in these metropolitan cities. Some of the small-scale industries, traditionally associated with labour are glasswork (Ferozabad), brasswork (Moradabad), utensils (Yamunanagar in Haryana), silk sarees (Varanasi), carpets (Mirzapur), etc.

6. Market: The existence of a market is the ultimate requirement of every industry because whatever is produced needs to be sold. High demand and satisfactory purchasing power provide impetus to industrial development. For example, heavy: chemical industries or machine industries are located in industrial areas because their products are required by other industries of the region. Similarly, petroleum refineries are established near markets as the transport of crude oil is easier. However, refineries using imported crude oil are located near ports.

School Geography Class 10 WBBSE

7. Climate: It plays a significant factor in the location of industries, especially agro-based industries. For instance, the cotton textile industry is located in Maharashtra which has a favourable climate and soil for the growth of cotton. An extreme type of climate, i.e., either located at Jamshedpur in Jharkhand. It was set up in 1951 and it started production of steam locomotives in 1951. Since 1970 the production of steam locomotives has been stopped.

Bharat Heavy Electricals Ltd (BHEL) has developed capabilities to manufacture electric locomotives for the Indian railways. Diesel Component works has been set up by the Indian Railways at Patiala for manufacturing and repairing of diesel loco components.

Question 25. State the factors favourable for the development of TISCO.
Answer: Tata Iron and Steel Company (TISCO) is one of the largest manufacturing plants in Asia. It is situated at Sakshi (now called Jamshedpur). It is the oldest steel plant in the country. The following factors were responsible for the plant being located at Jamshedpur:

1. Location: The TISCO plant is situated at Jamshedpur about 240 km northwest of Kolkata on the Kolkata-Nagpur rail line in the Singhbhum district. Jamshedpur is most ideally located with respect to iron ore, fuel and flux supplies which are obtained from within 175 km of it. Rivers Kharkai and Subarnarekha supply water.

2. Availability of Raw Materials: The plant obtains its requirements of iron ore from the Gurumahisani mines in the Mayurbhanj district of Orissa and from the Noamundi mines in the Singhbhum district of Jharkhand. These ore deposits are rich, containing over 60 per centurion in the ore. It receives manganese from Joda in the Keonjhar district, and limestone, dolomite and fire clay from the Sundergarh district of Orissa. Coal is obtained from the Jharia and Bokaro coal fields.

3. Power Supply: Coal is the main source of power for this plant. The supply of coal comes from Jharia and Bokaro coal fields located at a distance of about 177 km.
4. Water Supply: The two rivers Kharkai and Subarnarekha, which never run dry throughout the year, supply a continuous stream of water for cooling purposes.

5. Labour Force: The labour force for the plant is recruited from the densely populated valley of Ganga, mostly from the States of Bihar, West Bengal, Jharkhand, Chhattisgarh and Uttar Pradesh.
6. Market: The plant is located at a distance of 240 km from Kolkata which is not only an important market for the consumption of iron and steel goods but also has facilities for the export of finished goods.

School Geography Class 10 WBBSE

7. Transport Facilities: Jamshedpur is well-connected with roads and railways to the other parts of the country. The movement of raw materials and finished products is facilitated by the Eastern Railways. It is also connected with the Kolkata port for exporting of finished steel.

Question 26. Give an account of the Bokaro Steel plant.
Answer:
Bokaro Steel Plant: Bokaro steel plant was established in collaboration with the erstwhile USSR in 1964 (production started in 1972).

1. Location: The plant is located in the coal-rich and densely populated region of the Damodar valley near the confluence of the Bokaro and the Damodar rivers in the Hazaribagh district of Jharkhand.
2. Raw Materials: The plant obtains coal from Bokaro and Jharia coal fields; iron ore from the Kiriburu mines in Keonjhar district (Orissa); limestone from Bhabantpur and dolomite from Palamau (Jharkhand).

3. Power Supply: Power is supplied by Damodar Valley Corporation (DVC).
4. Water Supply: Water is obtained from a reservoir across the river Damodar.

Products: The plant has hot and cold rolling mills as its chief production units. They produce pig iron, crude steel and saleable steel. Its sludge and slag are used in making fertilizers at Sindhri.

Question 27. What are the reasons for the growth of the Durgapur Steel plant? State its major products.
Answer: Durgapur Steel Plant: This plant was set up during the Second Plan period at Durgapur in West Bengal with financial and technical assistance from the UK.

1. Location: It is situated along the Damodar river in the Burdwan district of West Bengal, about 160 km northwest of Kolkata on the Kolkata-Asansol rail line.
2. Raw Materials: The plant obtains iron ore from Singbhum (Jharkhand) and Keonjhar (Orissa). It gets coal from Jharia (Jharkhand) and Raniganj (W.B.); manganese from Keonjhar (Orissa) and limestone from Sundargarh district (Orissa).

3. Power Supply: Coal for the plant is obtained from the Jharia coal fields. Damodar Valley Corporation (DVC) has set up a 1,50,000 KW thermal station which supplies power to the plant. Besides this, 15,000 KW of power is generated within the plant.
4. Water Supply: Water is supplied from the Damodar river through a channel.

5. Transport Facilities: This plant is located on the Kolkata-Delhi rail line. In this way, it is connected with the major markets. It is also connected to the Kolkata port and, through a navigation canal, to the Hoogly River.
6. Labour Force: The labour force for the plant is recruited from Orissa, Bihar and Jharkhand.

Products: The plant specialises in the manufacture of alloy steel and railway items like wheels, axles and sleepers, ‘etc. It produces by-products like crude coal tar, ammonium sulphate, crude benzol, etc.

Question 28. Discuss the factors responsible for the growth of the Bhilai Iron & Steel plant.
Answer: Bhilai Steel Plant was established in collaboration with the (then) USSR Government at Bhilai in 1953.

1. Location: It is located 720 km west of Kolkata in the Durg district of Chhattisgarh.
2. Availability of Raw Materials: The plant gets its raw material from the following sources: Large iron ore deposits are supplied from Dhali Rajhara mines, about 80 km away from the plant. Limestone is drawn from the quarries developed in Nandini, 19 km from Bhilai. Manganese is obtained from the neighbouring district of Balaghat.

School Geography Class 10 WBBSE

3. Power Supply: Coal is obtained from Bokaro, Kargati and Jharia fields in Jharkhand and Korba in Chhattisgarh. The main source of power is the thermal power station at Korba.
4. Water Supply: The plant gets water from a system of reservoirs at Tendula.
5. Transport Facility: The Bhilai Steel Plant lies on the Mumbai-Nagpur-Kolkata rail line which links the plant to the major markets.
6. Labour Force: The labour for the plant is recruited from the nearby states of Bihar, Jharkhand and Madhya Pradesh.

Question 29. Discuss the factors responsible for the growth of IISCO.
Answer: It was established in 1981 at Burnpur in West Bengal. It had three separate plants, one at Hirapur, another at Kulti and the third at Burnpur. All these have been integrated into one unit. The management of IISCO was taken over by the Government of India in July 1972.

1. Location: The Lisco plants are situated at Bunpur, Hirapur and Kulti near Asansol about 227 km northwest of Kolkata.
2. Raw Materials: Iron ore is obtained from Singbhum (Jharkhand) and Mayurbhanj (Orissa), limestone from Sundergarh, and manganese from Jharkhand.

3. Power Supply: The supply of coal is obtained from the Jharia coalfield. Cheap hydroelectricity is provided by Damodar Valley Corporation.
4. Water Supply: Water is obtained from large reservoirs within the plant into which water is pumped from the Damodar river two miles away.

5. Labour: West Bengal, Jharkhand and Bihar provide labour to this plant.
6. Transport: Road and railways join the plant with Kolkata and other marketing centres. Kolkata provides port facilities for the movement of finished products.

Question 30. Briefly describe the Vijaynagar steel plant and the Vishakapatnam steel plant.
Answer:
Vijayanagar Steel Plant:
1. Location: Vijaynagar Steel Plant has been set up at Torangal near Hospet in the Bellary district of Karnataka.
2. Raw Materials: The plant gets iron ore from the Hospet region; good quality of limestone and dolomite from a distance of 200 km.
3. Power Supply: It gets coal from the Kanhan valley (Chhattisgarh) and Singareni (Andhra Pradesh) coal fields.
4. Water Supply: It gets water from the Tungabhadra reservoir (36 km from the plant site) and cheap hydel power from the Tungabhadra project.

Products: The plant specialises in ingot steel.

Vishakhapatnam Steel Plant:
1. Location: It is the first shore-based steel plant in India located at the port city of Visakhapatnam in Andhra Pradesh.
2. Raw Materials: The plant obtains iron ore from Bailadila in Chhattisgarh. It gets limestone, dolomite and manganese from the mines of Andhra Pradesh and Orissa.
3. Power Supply: It is well-connected with the coal fields of the Damodar Valley.

Question 31. What are the favourable factors for the Rourkela steel plant? State its major products.
Answer:
Rourkela Steel Plant: The Rourkela Steel Plant was built with technical cooperation from the German firm Krupps and Demang, in 1959.

1. Location: The plant is located at a distance of about 412 km from Kolkata at the confluence of two rivers, the Sankha and the Koel (Brahmani) in the Sundergarh district of Orissa.
2. Raw Materials: The plant is situated within 80 km of the high-grade iron ore reserves of the Sundergarh and Keonjhar districts in Orissa. Manganese is obtained from Barajmda, limestone from Bhirmitrapur and dolomite from Baradwar, all situated within a short distance from the plant.
3. Power Supply: Coal is obtained from Jharia, Talcher and Korba fields and electricity is from Hirakud Project.

4. Water Supply: Water is obtained from the Mandira dam across the Sankha river and also from Mahanadi.
5. Transport Facilities: Rourkela is situated on the Kolkata-Nagpur rail line. This provides easy access to raw material-producing areas and also to the markets.
6. Labour Force: It is recruited from Bihar, West Bengal, Jharkhand and Orissa.

Products: Its major products include hot-rolled sheets and strips, cold-rolled sheets, galvanised sheets and electrical steel plates. It also produces a large quantity of nitrogen as a by-product which is used for the manufacture of fertilisers and various chemicals.

Question 32. Describe the major units of the petrochemical industry in India.
Answer:
Production Units:
1. Union Carbide India Ltd: It is the first petrochemical complex and one of the biggest units. which was established in 1966 at Trombay in Maharashtra by Union Carbide. It manufactures films for packaging, bags, tarpaulins, godown covers, films, canal lining, industrial containers, insulation for electrical wires and cables, and pipes for carrying drinking water.

2. Herdillia Chemicals Ltd: It was set up in Chennai in collaboration with the Distillers Co. Ltd. of the UK and Hercules Power Co. of the USA. It manufactures a number of heavy organic chemicals like phenol, acetone, diacetone alcohol, and their derivatives, by-products, co-products and compounds.

3. National Organic Chemicals Industries Ltd: It is the biggest unit in India which was sponsored by Mafatlals in the Thana-Belapur area near Mumbai. It is also the first integrated plant in India which is based on the latest technology in the petrochemical field. The plant produces naphtha to produce ethylene, benzene, PVC, etc.

4. Petrofils Cooperative Limited (PCL): It is a joint venture of the Government of India and Weavers’ Cooperative Societies. It has three plants located at Vadodara and Naldhari in Gujarat. It manufactures yarn used for making swimsuits, undergarments, polyester filament yarn and nylon chips.
5. Indian Petrochemical Corporation Ltd: It is located at Jawaharnagar near Vadodara. It manufactures a number of petrochemicals like polymers, synthetic organic chemicals and fibres.

6. Bongaigaon Petrochemicals Ltd: It is located at Bongaigaon in Assam. It draws its raw materials from the Bongaigaon and Noonmati refineries.
7. The Reliance Industries: It is located at Hazira in Gujarat.