NEET Physics Laws of Motion MCQs Set A

a) all parts of the ball have the same velocity (magnitude and direction) and the velocity is constant

b) the path can be a straight line or circular and the ball travels with uniform speed

c) it is at rest

d) the centre of the ball moves with constant velocity and the ball spins about its centre uniformly

Answer:  all parts of the ball have the same velocity (magnitude and direction) and the velocity is constant

Question: A metre scale is moving with uniform velocity. This implies

a) the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero

b) the total force acting on it need not be zero but the torque on it is zero

c) neither the force nor the torque need to be zero

d) the force acting on the scale is zero, but a torque about the centre of mass can act on the scale

Answer: the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero

Question:

a)

b)

c)

d) zero

Answer:

Question:  Conservation of momentum in a collision between particles can be understood from

a) both Newton's second and third law

b) Newton's second law only

c) Newton's first law only

d) Conservation of energy

Answer:  both Newton's second and third law

Question:  A hockey player is moving northward and suddenly turns westward with the same speed to avoid an opponent. The force that acts on the player is

a) frictional force along sotuh-west

b) muscle force along south-west

c) muscle force along southward

d) frictional force along westward

Answer:  frictional force along sotuh-west

Question:

a) 10 s

b) 2 s

c) 15 s

d) never

Answer:  10 s

Question:

a) 136 N

b) 134 N

c) 158 N

d) 68 N

Answer:  136 N

Question:

a)

b)

c)

d)

Answer:

Question:  A balloon with mass ‘m’ is descending down with an acceleration ‘a’ (where a < g). How much mass should be removed from it so that it starts moving up with an acceleration ‘a’?

a) 

b)

c)

d)

Answer:

Question:   The force ‘F’ acting on a particle of mass ‘m’ is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is :

a) 12 Ns

b) 20 Ns

c) 24 Ns

d) 6 Ns

Answer:  12 Ns

Question:  A system consists of three masses m₁, m₂ and m₃ connected by a string passing over a pulley P. The mass m1 hangs freely and m₂ and m₃ are on a rough horizontal table (the coefficient of friction = m). The pulley is frictionless and of negligible mass. The downward acceleration of mass m₁ is : (Assume m₁ = m₂ = m₃ = m)

a)

b)

c)

d) None of these

Answer:

Question:  A mass is hanging on a spring balance which is kept in a lift. The lift ascends. The spring balance will show in its readings

a) an increase

b) a decrease

c) no change

d) a change depending on its velocity

Answer:  an increase

Question:

a)

b)

c)

d)

Answer:

Question:

a) 2

b) 1

c) 4

d) 3

Answer: 2

Question:  A plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches 30º the box starts to slip and slides 4.0 m down the plank in 4.0s. The coefficients of static and kinetic friction between the box and the plank will be, respectively :

a) 0.6 and 0.5

b) 0.5 and 0.6

c) 0.4 and 0.3

d) 0.6 and 0.6

Answer:  0.6 and 0.5

Question: Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If a force of 14 N is applied on the 4 kg block then the contact force between A and B is

a) 6 N

b) 8 N

c) 18 N

d)  2 N

Answer:  6 N

Question:

a)

b)

c)

d)

Answer:

Question:  A ball of mass 0.5 kg moving with a velocity of 2 m/sec strikes a wall normally and bounces back with the same speed. If the time of contact between the ball and the wall is one millisecond, the average force exerted by the wall on the ball is

a) 2000 newton

b) 5000 newton

c) 1000 newton

d) 125 newton

Answer:  2000 newton

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:  Given in the figure are two blocks A and B of weight 20 N and 100 N, respectively. These are being pressed against a wall by a force F as shown. If the coefficient of friction between the blocks is 0.1 and between block B and the wall is 0.15, the frictional force applied by the wall on block B is:

a) 120 N

b) 150 N

c) 100 N

d) 80 N

Answer:  120 N

Question:

a) 0.4

b) 0.2

c) 0.8

d) 0.1

Answer:  0.4

Question:

a)

b)

c)

d)

Answer:

Question:  What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop ?

a)

b)

c)

d)

Answer:

Question:  A smooth block is released at rest on a 45° incline and then slides a distance ‘d’. The time taken to slide is ‘n’ times as much to slide on rough incline than on a smooth incline. The coefficient of friction is

a)

b)

c)

d)

Answer:

Question:

a) zero

b) 0.2 ms^–2

c) 1.2 ms^–2

d) –1 ms^–2

Answer: zero

Question:  A frictionless wire AB is fixed on a sphere of radius R. Avery small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

a)

b)

c)

d)

Answer:

Question:  One end of string of length l is connected to a particle of mass 'm' and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in circle with speed 'v' the net force on the particle (directed towards centre) will be (T represents the tension in the string)

a) T

b) Zero

c)

d)

Answer: T

Question:  A hockey player is moving northward and suddenly turns westward with the same speed to avoid an opponent. The force that acts on the player is

a) frictional force along south-west

b) muscle force along south-west

c) muscles force along southward

d) muscles force along southward

Answer:  frictional force along south-west

Question:  The retarding acceleration of 7.35 ms^–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: 0.75

Question:

a) Assertion is incorrect, reason is correct

b) Assertion is correct, reason is incorrect

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer:  Assertion is incorrect, reason is correct

Question:

a)

b)

c)

d)

Answer:

Question:  Which one of the following statements is incorrect?

a) Coefficient of sliding friction has dimensions of length

b) Frictional force opposes the relative motion

c) Limiting value of static friction is directly proportional to normal reaction

d) Rolling friction is smaller than sliding friction

Answer:  Coefficient of sliding friction has dimensions of length

Question:

a)

b)

c)

d)

Answer:

Question:  What is the direction of force on the wall due to the ball in two cases shown in the figures?

a) In (a) and (b) both the force is normal to the wall

b) In (a) the force is along the wall and in (b) force is normal to the wall.

c) In (a) force is normal to the wall and in (b) force is inclined at 60° to the normal.

d) In (a) force is normal to the wall and in (b) force is inclined at 30° to the normal.

Answer: In (a) and (b) both the force is normal to the wall

Question: A boy, sitting on the topmost birth in the compartment of a train which is just going to stop on the railway station, drops an apple aiming at the open hand of his brother situated vertically below his own hand at a distance of 2m. The apple will fall

a) slightly away from the hand of his brother in the direction of motion of the train

b) slightly away from the hand of his brother opposite to the direction of motion of the train

c) None of the above

d) in the hand of his brother

Answer: slightly away from the hand of his brother in the direction of motion of the train

Question: Assertion: Friction forces are conservative forces.
Reason: Friction forces are unidirectional

a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

b) Assertion is correct, reason is incorrect

c) Assertion is incorrect, reason is correct.

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer:  Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Question:

a) 27.3 kg

b) 43.3 kg

c) 10.3 kg

d) 18.3 kg

Answer: 27.3 kg

Question: If a stone of mass 0.05 kg is thrown out a window of a train moving at a constant speed of 100 km/h then magnitude of the net force acting on the stone is

a) 0.5 N

b) zero

c) 50 N

d) 5 N

Answer:  0.5 N

MORE QUESTIONS.....................................

Question:

a) 200 N

b) 300 N

c) 150 N

d) 100 N

Answer: 200 N

Question:  A horizontal uniform rope of length L, resting on a frictionless horizontal surface, is pulled at one end by force F. What is the tension in the rope at a distance l from the end where the force is applied?

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

None of these

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question:  Block B has a mass m and is released from rest when it is on top of wedge A, which has a mass 3 m. Determine the extension of the spring of force constant k while B is sliding down on A. Neglect friction :

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question:  A body starts slipping down an incline and moves half metre in half second. How long will it take to move the next half?

a) 0.21 sec

b) 0.44 sec

c) 1.21 sec

d) 2.11 sec

Answer: 0.21 sec

Question:

a)

b)

c)

d)

Answer:

Question:  Two particles of equal mass are connected to a rope AB of negligible mass such that one is at end A and other dividing the length of rope in the ratio 1 : 2 from B. The rope is rotated about end B in a horizontal plane. Ratio of tensions in the smaller part to the other is (ignore effect of gravity)

a) 4 : 3

b) 1 : 4

c) 1 : 2

d) 1 : 3

Answer:  4 : 3

Question:

a) 12 m/s²

b) 16 m/s²

c) 8 m/s²

d) 4 m/s²

Answer:  12 m/s²

Question:  A body of mass M hits normally a rigid wall with velocity V and bounces back with the same velocity. The impulse experienced by the body is

a) 2 MV

b) zero

c) 1.5 MV

d) MV

Answer:  2 MV

Question:  An aircraft executes a horizontal loop with a speed of 150 m/ s with its wings banked at an angle of 12°. The radius of the loop is : (g = 10 m/s²)

a) 10.6 km

b) 9.6 km

c) 7.4 km

d) 5.8 km

Answer:  10.6 km

Question:  A particle describes a horizontal circle in a conical funnel whose inner surface is smooth with speed of 0.5 m/s. What is the height of the plane of circle from vertex of the funnel?

a) None of these

b) 4 cm

c) 2 cm

d) 0.25 cm

Answer: None of these

Question:  A car moving on a horizontal road may be thrown out of the road in taking a turn

a) due to the lack of proper centripetal force

b) by the gravitational force

c) Both

d) None of these

Answer:  due to the lack of proper centripetal force

Question: Identify the correct statement from the following.

a) Friction does not depend on the area in contact

b) Friction is always less than the applied force

c) None of these

d) Friction depends on the volume of body

Answer:  Friction does not depend on the area in contact