Chapter 2 Forces And Motion MCQs
Question 1. Definition of force is obtained from Newton’s
(1) First law of motion
(2) Second law of motion
(3) Law of Gravitation
(4) Third law of motion
Answer: (1) First law of motion
Question 2. Measurment of force is obtained from Newton’s
(1) Law of gravitation
(2) 1st law of motion
(3) Third law of motion
(4) 2nd law of motion
Answer: (4) 2nd law of motion
Question 3. Momentum is the product of mass and
(1) Force
(2) Time
(3) Velocity
(4) Speed
Answer: (3) Velocity
Question 4. A ball rolling on floor stops because
(1) Floor exerts a frictional force
(2) Gravity
(3) Absence of unbalanced force
(4) None of these
Answer: (1) Floor exerts a frictional force
Question 5. A force 2F acts on a body creating acceleration a; the mass of the body is
(1) F/a
(2) 2F/a
(3)2Fxa
(4) F/2a
Answer: (2) 2F/a
Question 6. A force acts on body at rest, distance moved by the body in time t is proportional to
(1) \(t^2\)
(2) t
(3) \(t^{-1}\)
(4) \(t^3\)
Answer: (1) \(t^2\)
Question 7. If a body is in acceleration then
(1) Its speed always increases
(2) Its velocity always increases
(3) Its velocity always decreases
(4) A force acts on it
Answer: (2) Its velocity always increases
Question 8. Due to action of an unbalanced force on a body, the acceleration of the body is proportional to
(1) The force acting on the body
(2) Velocity of the body
(3) Mass of the body
(4) Speed of the body
Answer: (1) The force acting on the body
Question 9. Newton’s third law of motion may be applied to a body
(1) Only at rest
(2) Only in motion
(3) Both at rest and in motion
(4) None of these
Answer: (3) Both at rest and in motion
Question 10. Two bodies X and Y have masses of 20 kg and 90 kg respectively. Which of the two have more inertia?
(1) Body x
(2) Body Y
(3) Both have equal inertia
(4) None of these
Answer: (1) Body x
Question 11. Velocity of a particle moving with uniform acceleration
(1)decreases
(2)Increases
(3) Remains unaltered
(4) None of these
Answer: (2) Increases
Question 12. A man moving around a square field, each side of which is 50 m in length, returns to the starting point. His displacement is
(1) 200 m
(2) 50 m
(3) 0m
(4) 100 m
Answer: (3) 0m
Question 13. A particle moving in a circular path with uniform speed has an acceleration
(1) Away from the center
(2) Towards the center
(3) Along the tangent at any point on a surface
(4) None of these
Answer: (2) Towards the center
Question 14. If a body covers equal distances in equal time intervals, then it is
(1) At rest
(2) Moving with uniform speed
(3) Moving with uniform velocity
(4) Moving with uniform acceleration
Answer: (2) Moving with uniform speed
Question 15. If a body moves with a constant speed, the distance-time graph is
(1) A straight line
(2) A circle
(3) A line like a staircase
(4) A polygon
Answer: (1) A straight line
Question 16. The area under the speed-time graph is
(1) Circle
(2) Parabola
(3) Distance
(4) None of these
Answer: (3) Distance
Question 17. The slope of a distance-time graph is
(1) Velocity
(2) Acceleration
(3) Displacement
(4) Speed
Answer: (4) Speed
Question 18. When a bus suddenly starts, the standing passengers lean backward in the. Bus, it is due to
(1) Newton’s first law
(2) Newton’s second law
(3) Newton’s third law
(4) None of these
Answer: (1) Newton’s first law
Question 19. The momentum of a body of given mass is proportional to its
(1) Volume
(2) Shape
(3) Speed
(4) Density
Answer: (3) Speed
Question 20. Which of the following has the largest inertia?
(1) A pin
(2) Your body
(3) An orange
(4) A brick
Answer: (2) Your body
Question 21. In absence of a force a body
(1) Can be at rest
(2) Moves with uniform speed
(3) Continues in its state of rest of motion
(4) (1) (2), (3), (4) all are correct
Answer:(4) (1) (2), (3), (4) all are correct
Question 22. Velocity is a
(1) Vector
(2) Scalar
(3) Both
(4) None
Answer: (1) Vector
Question 23. A body acted upon by a force must have
(1) Velocity
(2) Displacement
(3) Acceleration
(4) None of these
Answer: (3) Acceleration
Question 24. A body whose momentum is constant must have constant
(1) Force
(2) Velocity
(3) Acceleration
(4) All of these
Answer: (2) Velocity
Question 25. The motion of a rocket is based on the principle of conservation of
(1) Mass
(2) Kinetic energy
(3) Linear momentum
(4) Angular momentum
Answer: (3) Linear momentum
Question 26. A force of 250 N acts on a body and the momentum acquired by it is 125 kg m/s. What is the time for which the force acts on the body?
(1) 0.2’s
(2) 0.5s
(3) 0.4s
(4) 0.25 s
Answer: (2) 0.5 s
Question 27. A scooter of mass 200 kg is moving with a uniform velocity of 18 km/h. The force required to stop the vehicle in 10 s is
(1) 720 N
(2) 360 N
(3)180 N
(4) 216 N
Answer: (2) 360 N
Question 28. A body is moving with a constant speed in a straight line path. A force is not required to
(1) Increase its speed
(2) Change the direction
(3) Decrease the momentum
(4) Keep it moving with uniform velocity
Answer: (4) Keep it moving with uniform velocity
Question 29. A cricket player catches a ball of mass 0.1 kg moving with a speed of 10 m/s in 0.1 s. Force exerted by him is
(1) 10 N
(2) 5N
(3)2N
(4)1N
Answer: (1) 10 N
Question 30. What force will change the velocity of a body of mass 1 kg from 20 m/s to 30 m/ sin 2s?
(1) 25 N
(2) 5N
(3) 10 N
(4) 2N
Answer: (2) 5N
Question 31. The rocket engine lifts a rocket from the earth because hot gases with high
(1) Push it against the earth
(2) Push is against the air
(3) React against the rocket and push it up
(4) Heat the air which lifts the rocket
Answer: (3) React against the rocket and push it up
Question 32. A man is at rest in the middle of a pond on perfectly smooth ice. He can get himself to the shore by making use of Newton’s
(1) First law
(2) Second law
(3) Third law
(4) All the laws
Answer: (3) Third law
Question 33. A body of mass 2 kg is moving with a velocity of 8 m/s on.A smooth surface. If it is to be brought to rest in 4 s, then force to be applied is
(1) 8N
(2) 4N
(3)2N
(4)1N
Answer: (2) 4N