Chapter 7 Sound MCQs
Question 1. Sound can not travel through
(1) Air
(2) Water
(3) Steel
(4) Vacuum
Answer: (4) Vacuum
Question 2. Which frequencies are not audible to the human ear?
(1) 30 Hz
(2) 3000 Hz
(3) 300 Hz
(4) 30,000 Hz
Answer: (4) 30,000 Hz
Question 3. The frequency of sound waves can be expressed in
(1) Hz
(2) dB
(3) m
(4) m/s
Answer: (1) Hz
Question 4. Frequency (n) and period (T) are related as
(1)\(\frac{n}{T}\)=1
(2) n×T=1
(3) n=\(\mathrm{T}^2\)
(4) n\(\mathrm{T}^2\)=1
Answer: (2)
Question 5. The audible range of frequency in Hz is
(1) 20 to 20,000
(2) 2000 to 20,000
(3) 40 to 4000
(4) 200 to 2000
Answer: (1) 20 to 20,000
Question 6. Earthquake produces
(1) Audible sound
(2) Ultrasound
(3) Infrasonic sound
(4) None of these
Answer: (3) Infrasonic sound
Question 7. In SONAR, we use
(1) Radio waves
(2) Ultrasonic waves
(3) Infrasonic waves
(4) Audible sound waves
Answer: (2) Ultrasonic waves
Question 8. Due to the increase in the frequency of the sounding source, its pitch
(1) Increases
(2) Decreases
(3) Remains the same
(4) First increases and then decreases
Answer: (1) Increases
Question 9. Stethoscope works on the principle of
(1) Reflection of sound
(2) Refraction sound
(3) Reverberation of sound
(4) None of these
Answer: (1) Reflection of sound
Question 10. The relation between velocity (v) of sound, wavelength (λ), and frequency (n) is
(1) n\(=\frac{v}{\lambda}\)
(2) λ=vm
(3) n= λv
(4) n\(=\frac{v^2}{\lambda}\)
Answer: (1) n\(=\frac{v}{\lambda}\)
Question 11. The velocity of sound in dry air at 0°C is
(1) 233 m/s
(2) 330 m/s
(3) 332 m/s
(4) 200 m/s
Answer: (3) 332 m/s
Question 12. The minimum distance of the reflector creating an echo of a transient sound is
(1) 33m
(2) 16.6 m
(3) 33 cm
(4) 10m
Answer: (2) 16.6 m
Question 13. Propagation of sound requires
(1) No medium
(2) Material medium
(3) Only gaseous medium
(4) Aqueous medium
Answer: (2) Material medium
Question 14. Echo of sound is caused by
(1) Violent sound
(2) Flow of air
(3). Reflection of sound
d) Refraction of sound
Answer: (3) Reflection of sound
Question 15. The unit of intensity of sound is
(1) Hertz
(2) m/\(s^2\)
(3) Decibel
(4) Dyne
Answer: (3) Decibel
Question 16. Due to the propagation of a longitudinal wave through a medium, particles of the medium vibrate
(1) Along and perpendicular to the direction of the wave
(2) In all directions
(3) Along the direction of the wave
(4) Within a liquid
Answer: (3) Along the direction of the wave
Question 17. A transverse wave is produced in
(1) Gas only
(2) A liquid
(3) In gas, solid and liquid
(4) Solid only
Answer: (3) In gas, solid and liquid
Question 18. Distance traveled by a wave in one second is its
(1) Velocity
(2) Wavelength
(3) Period
(4) Frequency
Answer: (1) Velocity
Question 19. The correct formula is
(1) v\(=1 / T\)
(2) v=nλ
(3) \(=\frac{v}{\lambda}\)
(4) v=\(\mathrm{n}_2\).λ
Answer: (2) v=nλ
Question 20. The loudness of the sound depends on
(1) Wavelength of sound
(2) Volume of air around the source of sound
(3) Time of day
(4) Reflection of sound
Answer: (1) Wavelength of sound
Question 21. The human ear is sensitive normally between the frequencies
(1) 20-20,000 Hz
(2) 10-100 Hz
(3) 1-10 Hz
(4) Above 20,000
Answer: (1) 20-20,000 Hz
Question 22. For hearing echo the minimum time difference between the direct and the reflected sound should be
(1) 1/5 sec
(2) 1/10 sec
(3) 1 sec
(4) 2 sec
Answer: (2) 1/10 sec.
Question 23. For a sound of wavelength 10 cm and frequency 10 created in a medium, the velocity of a sound wave is
(1) 10 cm/sec
(2) 100 cm/sec
(3) 5 cm/sec
(4) 20 cm/sec
Answer: (2) 100 cm/sec
Question 24. The surface of a wall can reflect sound waves and not light waves because
(1) Sound has bigger wavelength
(2) The wall is large
(3) Sound has less velocity
(4) Sound has bigger velocity
Answer: (1) Sound has bigger wavelength
Question 25. Elastic transverse waves can propagate through
(1) Gaseous medium not through solid medium
(6) Neither gaseous nor solid medium
(3) Solid and gaseous medium
(4) Solid medium, not through gaseous medium
Answer: (4) Solid medium, not through gaseous medium
Question 26. Repeated reflection of sound produces
(1) Stationary wave
(2) Echo
(3) Reverberation
(4) Refraction
Answer: (2) Echo
Question 27. The velocity of a sound wave of wavelength 1 in a medium is v, The wavelength of the wave in the medium of the velocity is 4 v, is
(1) λ/2
(2) 2/λ
(3) 4/λ
(4) 2/λ
Answer: (3) 4/λ
Question 28. The difference in intensity between two sound waves is 1 Bel. It means that the ratio of their intensities is
(1) 5:1
(2) 105
(3) 1:4
(4) 100: 4
Answer: (3) 1:1
Question 29. Which of the following is not true?
(1) Sound waves do not propagate in straight lines
(2) Sound wave carries energy
(3) Sound waves travel faster in a vacuum than in air
(4) Sound waves propagate in straight lines
Answer: (3) Sound waves travel faster in vacuum than in air
Question 30. The pitch of a note depends on the
(1) Frequency
(2) Velocity of sound
(3) Wavelength of sound
(4) Amplitude of wave
Answer: (3) Wavelength of sound
Question 31. The velocity of sound is greatest in
(1) Mercury
(2) Water
(3) Steel
(4) Air
Answer: (3) Steel
Question 32. The sound of thunder is heard after 5.5 sec after the flash. If the velocity of sound in air is 330 m/sec, the distance of the thunder is
(1) 18.15 km
(2) 1.815 km
(3) 0.1815 km
(4) 181.5 km
Answer: (2) 1.815 km
Question 33. A person fires a pistol standing between two hills. He hears echoes at 1-sec intervals. If the velocity of sound in air is 340 m/sec, the distance between the mountains is
(1) 340 m
(2) 170 m
(3) 510 m
(4) 66 m
Answer: (2) 170 m
Question 34. The characteristic by which two sounds of the same frequency and loudness can be differentiated is
(1) Velocity of sound
(4) Quality
(3) Pitch
(4) Medium in which the sound travels
Answer: (3) Pitch
Question 35. When a wave travels from one medium to another, the parameter of the wave
remaining unchanged is
(1) Quality
(2) Velocity
(3) Frequency
(4) Wavelength
Answer: (1) Quality
Question 36. What should be the minimum frequency of a vibrating body producing sound?
(1) 2000 Hz
(2) 100 Hz
(3) 20 Hz
(4) 150 Hz
Answer: (3) 20 Hz
Question 37. How does the pitch of sound depend on frequency?
(1) Pitch increases with a decrease in frequency
(2) Pitch decreases with increase in frequency
(3) Pitch increases or decreases accordingly with an increase or decrease in frequent
(4) Pith remains constant
Answer: (3) Pitch increases or decreases accordingly with increase or decrease in frequency.
Question 38. The Unit Of Frequency is
(1) ohm
(2) mho
(3) Hz
(4) Torr
Answer: (3) Hz
Question 39. Migraine is caused by
(1) Sound pollution
(2) Air pollution
(3) Water pollution
(4) Land pollution
Answer: (1) Sound pollution
Question 40. When one end of a long iron pipe is struck, sounds are heard.
(1) Two
(2) Three
(3) Four
(4) One
Answer: (1) Two
Question 41. The relation between the velocity (v) of sound and its density (d) is
(1)\(v \propto \frac{1}{d}\)
(2)\(v \propto \frac{1}{\sqrt{d}}\)
(3)\(\frac{1}{d}\)
(4) V α T
Answer: (2)\(v \propto \frac{1}{\sqrt{d}}\)
Question 42. The relation between the velocity (v) of sound with the absolute temperature (T) is
(1) v α \(\sqrt{T}\)
(2) v α T
(3) v=T
(4) v= \(\sqrt{T}\)
Answer: (1) v α \(\sqrt{T}\)
Question 43. If the size of the sounding body is bigger then the intensity of the sound will be
(1) Increased
(2). Decreased
(3) Same
(4) Constant
Answer: (1) Increased
Question 44. The velocity of sound through iron is then the velocity of sound through air.
(1) 4 times
(2) 10 times
(3) 15 times
(4) 5 times
Answer: (3) 15 times
Question 45. The sensation due to sound lasts for about
(1) \(\frac{1}{20}\) second
(2) \(\frac{1}{10}\) t second
(3) \(\frac{1}{30}\) Secon
(4) \(\frac{1}{5}\) secon
Answer: (2) \(\frac{1}{10}\) second
Question 46. If the wave length is and the velocity of sound 1.7 m is 340 m/sec then what will be the wave frequency?
(1) 20 Hz
(2) 200 Hz
(3) 2000 Hz
(4) 2 Hz
Answer: (2) 200 Hz
Question 47. If the tones present in a note are of frequencies 100, 150, 200, 280, 300, 450, and 500, what is the fundamental tone?
(1) 100
(2) 280
(3) 500
(4) 450
Answer: (1) 100
Question 48. The sound of lightning is heard 6 sec after it is seen. If the velocity of sound is 330 m/sec at that time, what will be the distance of the cloud?
(1) 1980 m
(2) 2000
(3) 330 m
(4) 350 m
Answer: (1) 1980 m
Question 49. Wave motion transfers
(1) Matter
(2) Energy
(3) Momentum
(4) All of these
Answer: (2) Energy
Question 50. The distance between two successive compressions is
(1) λ/2
(2) λ/4
(3) λ
(4) 2 λ
Answer: (3) λ
Question 51. Sound waves can travel
(1) Only in solid
(2) Only in liquid
(3) Only in gas
(4) In all (Solid, Liquid, gas)
Answer: (4) In all (Solid, Liquid, gas)
Question 52. The speed of sound in air
(1) Decreases with increase in temperature
(2) Remains the same with an increase in temperature
(3) Remains the same with a decrease in temperature
(4) Increases with increase in temperature
Answer: (1) Decreases with an increase in temperature
Question 53. Sound wave is
(1) Transverse
(2) Longitudinal
(3) Both transverse and longitudinal
(4) None of these
Answer: (2) Longitudinal in nature
Question 54. The distance between a compression and the adjoining rarefaction is
(1) λ/4
(2) λ/2
(3) λ
(4) 2λ
Answer: (2) λ/2
Question 55. Which of the following waves is a mechanical wave?
(1) Lightwave
(2) Sound wave
(3) X-rays
(4) Ultra-violet ray
Answer: (2) Sound wave
Question 56. The speed of sound is maximum in
(1) Air
(2) Hydrogen
(3) Water
(4) Iron
Answer: (4) Iron
Question 57. In SONAR, we use
(1) Infrasonic
(2) Radiowaves
(3) Audible sound
(4) Ultrasonic
Answer: (4) Ultrasonic
Question 58. Infrasound can be heard by
(1) Bat
(2) Rhinoceros
(3) Dolphins
(4) Human beings
Answer:(2) Rhinoceros
