NEET Physics Friction MCQs Set A

Question. The coefficient of static friction between two surfaces depends upon
(a) the normal reaction
(b) the shape of the surface in contact
(c) the magnitude of applied force
(d) None of these

Answer: A

Question. If the applied force is doubled, then coefficient of friction is
(a) not changed
(b) tripled
(c) halved
(d) doubled

Answer: A

Question. When a box is in stationary position with respect to train moving with acceleration, then relative motion is opposed by the ...X.... Which provides the same acceleration to the box as that of the train, keeping it stationary relative to the train. Here, X refers to
(a) static friction
(b) None of these
(c) kinetic friction
(d) limiting friction

Answer: A

Question. It is difficult to move a cycle with brakes on because
(a) sliding friction is more than rolling friction
(b) rolling friction is more than sliding friction
(c) sliding friction opposes motion on road
(d) rolling friction opposes motion on road

Answer: A

Question. Select the incorrect statement(s) about static friction.
I. Static friction exists on its own.
II. In the absence of applied force static friction is maximum.
III. Static friction is equal and opposite to the applied force upto a certain limit.
(a) I and II
(b) I and III
(c) II and III
(d) I only

Answer: A

Question. Which of the following statements about friction is true?
(a) Kinetic friction is always greater than rolling friction
(b) Frictional force is proportional to the area of contact between the two surfaces
(c) Frictional force cannot accelerate a body.
(d) Friction can be reduced to zero.

Answer: A

Question. Select the incorrect statement(s) from the following.
I. Limiting friction is always greater than the kinetic friction.
II. Limiting friction is always less than the static friction.
III. Coefficient of static fiction is always greater than the coefficient of kinetic fiction
(a) II and III
(b) I and II
(c) I and III
(d) I only

Answer: C

Question. A conveyor belt is moving at a constant speed of 2m/s. A box is gently dropped on it. The coefficient of friction between them is μ = 0.5. The distance that the box will move relative to belt before coming to rest on it taking g = 10 ms^–2, is
(a) 0.4 m
(b) zero
(c) 0.6 m
(d) 1.2 m

Answer: A

Question. A body of mass 2 kg is placed on a horizontal surface having kinetic friction 0.4 and static friction 0.5. If the force applied on the body is 2.5 N, then the frictional force acting on the body will be [g = 10 ms^–2]
(a) 2.5 N
(b) 20 N
(c) 10 N
(d) 8 N

Answer: A

Question. A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by friction in 10 s. Then the coefficient of friction is (Take g = 10 ms^–2)
(a) 0.06
(b) 0.03
(c) 0.04
(d) 0.01

Answer: A

Question. A block rests on a rough inclined plane making an angle of 30° with the horizontal. The coefficient of static friction between the block and the plane is 0.8. If the frictional force on the block is 10 N, the mass of the block (in kg) is  (take g = 10 m / s² )
(a) 2.0
(b) 2.5
(c) 4.0

Answer: A

Question. A block of mass 0.1kg is held against a wall applying a horizontal force of 5 N on the block. If the coefficient of friction between the block and the wall is 0.5, the magnitude of the frictional force acting on the block is:
(a) 0.98 N
(b) 4.9 N
(c) 0.49 N
(d) 2.5 N

Answer: A

Question. The retarding acceleration of 7.35 m s^–2 due to frictional force stops the car of mass 400 kg travelling on a road. The coefficient of friction between the tyre of the car and the road is
(a) 0.75
(b) 0.70
(c) 0.65
(d) 0.55

Answer: A

Question. A block A of mass 4 kg is placed on another block B of mass 5 kg, and the block B rests on a smooth horizontal table. If the minimum force that can be applied on A so that both the blocks move together is 12 N, the maximum force that can be applied to B for the blocks to move together will be
(a) 27 N
(b) 48 N
(c) 25 N
(d) 30 N

Answer: A