CBSE Class 11 Physics Laws Of Motion Worksheet

Laws Of Motion MCQ Questions with Answers Class 11 Physics

Question. A cyclist moves in a circular track of radius 100 m. If the coefficient of friction is 0.2, then the maximum velocity with which the cyclist can take the turn with leaning inwards is
(a) 9.8 m/s
(b) 1.4 m /s
(c) 140 m/s
(d) 14 m/s

Answer: D

Question. If the normal force is doubled, the coefficient of friction is
(a) Not changed
(b) Halved
(c) Doubled
(d) Tripled

Answer: A

Question. Block A weighing 100 kg rests on a block B and is tied with a horizontal string to the wall at C. Block B weighs 200 kg. The coefficient of friction between A and B is 0.25 and between B and the surface is 1/3. The horizontal force P necessary to move the block B should be (g=10m/s²)
(a) 1150 N
(b) 1250 N
(c) 1300 N
(d) 1420 N

Answer: B

Question. When a horse pulls a cart, the horse moves down to
(a) horse on the cart.
(b) cart on the horse.
(c) horse on the earth.
(d) earth on the horse.

Answer: D

Question. A spring is compressed between two toy carts of mass m₁ and m₂. When the toy carts are released, the springs exert equal and opposite average forces for the same time on each toy cart. If v₁ and v₂ are the velocities of the toy carts and there is no friction between the toy carts and the ground, then :
(a) v₁/v₂ = m₁/m₂
(b) v₁/v₂ = m₂/m₁
(c) v₁/v₂ = –m₂/m₁
(d) v1/v2 = –m₁/m₂

Answer: C

Question. A monkey is climbing up a rope, then the tension in the rope
(a) must be equal to the force applied by the monkey on the rope
(b) must be less than the force applied by the monkey on the rope.
(c) must be greater than the force applied by the monkey on the rope.
(d) may be equal to, less than or greater the force applied by the monkey on the rope.

Answer: A

Question. A uniform rope of length L resting on a frictionless horizontal surface is pulled at one end by a force F. What is the tension in the rope at a distance l from the end where the force is applied.
(a) F
(b) F (1 + l/L)
(c) F/2
(d) F (1 – l/L)

Answer: D

Question. A particle of mass m is moving with velocity v₁, it is given an impulse such that the velocity becomes v₂. Then magnitude of impulse is equal to
(a) m(v̅₂ - v̅₁) 
(b) m(v̅₁ - v̅₂) 
(c) m x (v̅₂ - v̅₁) 
(d) 0.5m(v̅₂ - v̅₁) 

Answer: A

Question. A rectangular block is placed on a rough horizontal surface in two different ways as shown, then 

(a) friction will be more in case (a)
(b) friction will be more in case (b)
(c) friction will be equal in both the cases
(d) friction depends on the relations among its dimensions.

Answer: C

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: A

Question. A cart of mass M has a block of mass m attached to it as shown in fig. The coefficient of friction between the block and the cart is m. What is the minimum acceleration of the cart so that the block m does not fall?

(a) μg
(b) g/μ
(c) μ/g
(d) M μg/m

Answer: B

Question. A force of 10 N acts on a body of mass 20 kg for 10 seconds.
Change in its momentum is
(a) 5 kg m/s
(b) 100 kg m/s
(c) 200 kg m/s
(d) 1000 kg m/s

Answer: B

Question. The force of action and reaction
(a) must be of same nature
(b) must be of different nature
(c) may be of different nature
(d) may not have equal magnitude

Answer: A

Question. A particle of mass m moving eastward with a speed v collides with another particle of the same mass moving northward with the same speed v. The two particles coalesce on collision. The new particle of mass 2m will move in the northexternal direction with a velocity :
(a) v/2
(b) 2v
(c) v /√2
(d) None of these

Answer: C

Question. A rider on a horse back falls forward when the horse suddenly stops. This is due to
(a) inertia of horse
(b) inertia of rider
(c) large weight of the horse
(d) losing of the balance

Answer: B

Question. Centripetal force :
(a) can change speed of the body.
(b) is always perpendicular to direction of motion
(c) is constant for uniform circular motion.
(d) all of these

Answer: B

Question. Two mass m and 2m are attached with each other by a rope passing over a frictionless and massless pulley. If the pulley is accelerated upwards with an acceleration ‘a’, what is the value of T?
(a) g+a/3
(b) g-a/3
(c) 4m(g + a)/3
(d) m(g - a)/3

Answer: C

Question. The direction of impulse is
(a) same as that of the net force
(b) opposite to that of the net force
(c) same as that of the final velocity
(d) same as that of the initial velocity

Answer: A

Question. A constant force F = m²g/2 is applied on the block of mass m1 as shown in fig. The string and the pulley are light and the surface of the table is smooth. The acceleration of m₁ is 

Answer: A

Question. A ball of mass m is thrown vertically upwards. What is the rate at which the momentum of the ball changes?
(a) Zero
(b) mg
(c) Infinity
(d) Data is not sufficient.

Answer: B

Question. A body is moving with uniform velocity, then
(a) no force must be acting on the body.
(b) exactly two forces must be acting on the body
(c) body is not acted upon by a single force.
(d) the number of forces acting on the body must be even.

Answer: C

Question. A machine gun has a mass 5 kg. It fires 50 gram bullets at the rate of 30 bullets per minute at a speed of 400 ms–1. What force is required to keep the gun in position?
(a) 10 N
(b) 5 N
(c) 15 N
(d) 30 N

Answer: A

Question. A particle starts sliding down a frictionless inclined plane.
If S_n is the distance traveled by it from time t = n – 1 sec to t = n sec, the ratio S_n/S_n+1 is
(a) 2n -1/2n +1
(b) 2n +1/2n
(c) 2n/2n +1
(d) 2n +1/2n -1

Answer: A

Question. A small block is shot into each of the four tracks as shown below. Each of the tracks rises to the same height. The speed with which the block enters the track is the same in all cases. At the highest point of the track, the normal reaction is maximum in 

Answer: A

Question. A toy gun consists of a spring and a rubber dart of mass 16 g. When compressed by 4 cm and released, it projects the dart to a height of 2 m. If compressed by 6 cm, the height achieved is
(a) 3 m
(b) 4 m
(c) 4.5 m
(d) 6 m

Answer: C

Question. A player stops a football weighting 0.5 kg which comes flying towards him with a velocity of 10m/s. If the impact lasts for 1/50th sec. and the ball bounces back with a velocity of 15 m/s, then the average force involved is
(a) 250 N
(b) 1250 N
(c) 500 N
(d) 625 N

Answer: D

Question. A block is kept on a inclined plane of inclination q of length l . The velocity of particle at the bottom of inclined is (the coefficient of friction is μ) 

Answer: B

Question. A block of mass m on a rough horizontal surface is acted upon by two forces as shown in figure. For equilibrium of block the coefficient of friction between block and surface is 

Answer: A

Question. A car travelling at a speed of 30 km/h is brought to a halt in 4 m by applying brakes. If the same car is travelling at 60 km/h, it can be brought to halt with the same braking power in
(a) 8 m
(b) 16 m
(c) 24 m
(d) 32 m

Answer: B

Question. A bird is in a wire cage which is hanging from a spring balance . In the first case, the bird sits in the cage and in the second case, the bird flies about inside the cage. The reading in the spring balance is
(a) more in the first case
(b) less in first case
(c) unchanged
(d) zero in second case.

Answer: A

Question. A weight W rests on a rough horizontal plane. If the angle of friction be q , the least force that will move the body along the plane will be
(a) W cos θ
(b) W cot θ
(c) W tan θ
(d) W sin θ

Answer: C

Question. A solid sphere of 2 kg is suspended from a horizontal beam by two supporting wires as shown in fig. Tension in each wire is approximately (g = 10 ms^–2) 

(a) 30 N
(b) 20 N
(c) 10 N
(d) 5 N

Answer: B

Question. A plate of mass M is placed on a horizontal of frictionless surface (see figure), and a body of mass m is placed on this plate. The coefficient of dynamic friction between this body and the plate is m . If a force 2 m mg is applied to the body of mass m along the horizontal, the acceleration of the plate will be 

Answer: A

Question. An object of mass 10 kg moves at a constant speed of 10 ms^–1. A constant force, that acts for 4 sec on the object, gives it a speed of 2 ms^–1 in opposite direction. The force acting on the object is
(a) –3 N
(b) –30 N
(c) 3 N
(d) 30 N

Answer: A

Question. Fig. shows a uniform rod of length 30 cm having a mass of 3.0 kg. The strings shown in the figure are pulled by constant forces of 20 N and 32 N. All the surfaces are smooth and the strings and pulleys are light. The force exerted by 20 cm part of the rod on the 10 cm part is 

(a) 20 N
(b) 24 N
(c) 32 N
(d) 52 N

Answer: B

Question. In an explosion, a body breaks up into two pieces of unequal masses. In this
(a) both parts will have numerically equal momentum
(b) lighter part will have more momentum
(c) heavier part will have more momentum
(d) both parts will have equal kinetic energy

Answer: A

Question. A body of mass 4 kg moving on a horizontal surface with an initial velocity of 6 ms–1 comes to rest after 3 seconds. If one wants to keep the body moving on the same surface with the velocity of 6 ms–1, the force required is
(a) Zero
(b) 4 N
(c) 8 N
(d) 16 N

Answer: C

Question. A force time graph for the motion of a body is shown in Fig.
Change in linear momentum between 0 and 8s is

(a) zero
(b) 4 N-s
(c) 8 Ns
(d) None of these

Answer: A

Question. A lift is moving downwards with an acceleration equal to acceleration due to gravity. A body of mass M kept on the floor of the lift is pulled horizontally. If the coefficient of friction is μ, then the frictional resistance offered by the body is
(a) Mg
(b) μMg
(c) 2Mgμ
(d) Zero

Answer: D

Question. In the above question, if the lift is moving upwards with a uniform velocity, then the frictional resistance offered by the body is
(a) Mg
(b) Mg μ
(c) 2μMg
(d) Zero

Answer: B

Question. A body of mass 2 kg is moving on the ground comes to rest after some time. The coefficient of kinetic friction between the body and the ground is 0.2. The retardation in the body is
(a) 9.8 m / s²
(b) 4.73m / s²
(c) 2.16m / s²
(d) 1.96m / s²

Answer: D

Question. A body of weight 50 N placed on a horizontal surface is just moved by a force of 28.2 N. The frictional force and the normal reaction are
(a) 10 N, 15 N
(b) 20 N, 30 N
(c) 2 N, 3 N
(d) 5 N, 6 N

Answer: B

Question. A block of mass 5 kg lies on a rough horizontal table. A force of 19.6 N is enough to keep the body sliding at uniform velocity. The coefficient of sliding friction i
(a) 0.5
(b) 0.2
(c) 0.4
(d) 0.8

Answer: C

Question. A stone weighing 1 kg and sliding on ice with a velocity of 2 m/s is stopped by friction in 10 sec. The force of friction (assuming it to be constant) will be
(a) -20 N
(b) -0.2 N
(c) 0.2 N
(d) 20 N

Answer: B

Question. A force of 19.6 N when applied parallel to the surface just moves a body of mass 10 kg kept on a horizontal surface. If a 5 kg mass is kept on the first mass, the force applied parallel to the surface to just move the combined body is
(a) 29.4 N
(b) 39.2 N
(c) 18.6 N
(d) 42.6 N

Answer: A

Question. A motor car has a width 1.1 m between wheels. Its centre of gravity is 0.62 m above the ground and the coefficient of friction between the wheels and the road is 0.8. What is the maximum possible speed, if the centre of gravity inscribes a circle of radius 15 m? (Road surface is horizontal)
(a) 7.64 m/s
(b) 6.28 m/s
(c) 10.84 m/s
(d) 11.23 m/s

Answer: C

Question. A 2 kg mass starts from rest on an inclined smooth surface with inclination 30o and length 2 m. How much will it travel before coming to rest on a frictional surface with frictional coefficient of 0.25
(a) 4 m
(b) 6 m
(c) 8 m
(d) 2 m

Answer: A

Question. It is easier to roll a barrel than pull it along the road. This statement is
(a) False
(b) True
(c) Uncertain
(d) Not possible

Answer: B

Question. A block of mass 1 kg slides down on a rough inclined plane of inclination 60° starting from its top. If the coefficient of kinetic friction is 0.5 and length of the plane is 1 m, then work done against friction is (Take g = 9.8 m/s²)
(a) 9.82 J
(b) 4.94 J
(c) 2.45J
(d) 1.96 J

Answer: C

Question. Two blocks of masses 2 kg and 1 kg are placed on a smooth horizontal table in contact with each other. A horizontal force of 3 newton is applied on the first so that the block moves with a constant acceleration. The force between the blocks would be
(a) 3 newton
(b) 2 newton
(c) 1 newton
(d) zero

Answer: C

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) 1000 newton
(c) 5000 newton
(d) 125 newton

Answer: A

Question. Consider the system shown in fig. The pulley and the string are light and all the surfaces are frictionless. The tension in the string is (take g = 10 m/s²) 

(a) 0 N
(b) 1 N
(c) 2 N
(d) 5 N

Answer: D

Question. The elevator shown in fig. is descending with an acceleration of 2 m/s². The mass of the block A = 0.5 kg. The force exerted by the block A on block B is 

(a) 2 N
(b) 4 N
(c) 6 N
(d) 8 N

Answer: B

Question. A 40 kg slab rests on frictionless floor as shown in fig. A 10 kg block rests on the top of the slab. The static coefficient of friction between the block and slab is 0.60 while the kinetic friction is 0.40. The 10 kg block is acted upon by a horizontal force of 100 N. If g = 9.8 m/s², the resulting acceleration of the slab will be:
(a) 0.98 m/s²
(b) 1.47 m/s²
(c) 1.52 m/s²
(d) 6.1 m/s²

Answer: A

Question. Two blocks are connected over a massless pulley as shown in fig. The mass of block A is 10 kg and the coefficient of kinetic friction is 0.2. Block A slides down the incline at constant speed. The mass of block B in kg is: 

(a) 3.5
(b) 3.3
(c) 3.0
(d) 2.5

Answer: B

Question. Two trolleys of mass m and 3m are connected by a spring. They were compressed and released at once, they move off in opposite direction and come to rest after covering a distance S₁, S₂ respectively. Assuming the coefficient of friction to be uniform, ratio of distances S₁ : S₂ is :
(a) 1 : 9
(b) 1 : 3
(c) 3 : 1
(d) 9 : 1

Answer: D

Question. A particle of mass 10 kg is moving in a straight line. If its displacement, x with time t is given by x = (t³ – 2t – 10) m, then the force acting on it at the end of 4 seconds is
(a) 24 N
(b) 240 N
(c) 300 N
(d) 1200 N

Answer: B

Question. When forces F₁, F₂, F₃ are acting on a particle of mass m such that F₂ and F₃ are mutually perpendicular, then the particle remains stationary. If the force F₁ is now removed then the acceleration of the particle is
(a) F₁/m
(b) F₂F₃/mF₁
(c) (F₂ – F₃)/m
(d) F2/m

Answer: A

Question. One end of massless rope, which passes over a massless and frictionless pulley P is tied to a hook C while the other end is free. Maximum tension that the rope can bear is 360 N. With what value of maximum safe acceleration (in ms^–2) can a man of 60 kg moves downwards on the rope? [Take g = 10 ms^–2] 

(a) 16
(b) 6
(c) 4
(d) 8

Answer: C

Question. In the previous problem (3), the magnitude of the momentum transferred during the hit is
(a) zero
(b) 0.75 kg-m s^–1
(c) 1.5 kg-m s^–1
(d) 1.4 kg-m s^–1

Answer: C

Question. Two blocks A and B of masses 3 m and m respectively are connected by a massless and inextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of A and B immediately after the string is cut, are respectively : 

Answer: A

Question. A 4000 kg lift is accelerating upwards. The tension in the supporting cable is 48000 N. If g = 10ms^-2 then the acceleration of the lift is
(a) 1 ms^-2
(b) 2 ms^-2
(c) 4 ms^-2
(d) 6 ms^-2

Answer: B

Question. The mass of the lift is 100 kg which is hanging on the string.
The tension in the string, when the lift is moving with constant velocity, is (g = 9.8 m/sec²)
(a) 100 newton
(b) 980 newton
(c) 1000 newton
(d) None of these

Answer: B

Question. In the question , the tension in the strings, when the lift is accelerating up with an acceleration 1 m/sec², is
(a) 100 newton
(b) 980 newton
(c) 1080 newton
(d) 880 newton

Answer: C

Question. A small sphere is attached to a cord and rotates in a vertical circle about a point O. If the average speed of the sphere is increased, the cord is most likely to break at the orientation when the mass is at 

(a) bottom point B
(b) the point C
(c) the point D
(d) top point A

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) 8 N
(b) 10 N
(c) 20 N
(d) 2.5 N

Answer: D

Question. A body of mass 2 kg travels according to the law x(t) = pt + qt² + rt³ where, q = 4 ms^–2, p = 3 ms^–1 and r = 5 ms^–3. The force acting on the body at t = 2s is
(a) 136 N
(b) 134 N
(c) 158 N
(d) 68 N

Answer: A

Question. Blocks A and B of masses 15 kg and 10 kg, respectively, are connected by a light cable passing over a frictionless pulley as shown below. Approximately what is the acceleration experienced by the system? 

(a) 2.0 m/s²
(b) 3.3 m/s²
(c) 4.9 m/s²
(d) 9.8 m/s²

Answer: A

Question. Block A is moving with acceleration A along a frictionless horizontal surface. When a second block, B is placed on top of Block A the acceleration of the combined blocks drops to 1/5 the original value. What is the ratio of the mass of A to the mass of B?
(a) 5 : 1
(b) 1 : 4
(c) 3 : 1
(d) 2 : 1

Answer: B

Question. A force F is used to raise a 4-kg mass M from the ground to a height of 5 m. 

What is the work done by the force F? (Note : sin 60° = 0.87; cos 60° = 0.50. Ignore friction and the weights of the pulleys)
(a) 50 J
(b) 100 J
(c) 174 J
(d) 200 J

Answer: D

Question. A 5000 kg rocket is set for vertical firing. The exhaust speed is 800 m/s. To give an initial upward acceleration of 20 m/s², the amount of gas ejected per second to supply the needed thrust will be (Take g = 10 m/s²)
(a) 127.5 kg/s
(b) 137.5 kg/s
(c) 155.5 kg/s
(d) 187.5 kg/s

Answer: D

Question. A bullet is fired from a gun. The force on the bullet is given by F = 600 – 2 × 10⁵ t Where, F is in newtons and t in seconds. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to the bullet?
(a) 1.8 N-s
(b) Zero
(c) 9 N-s
(d) 0.9 N-s

Answer: D

Question. A 50 kg ice skater, initially at rest, throws a 0.15 kg snowball with a speed of 35 m/s. What is the approximate recoil speed of the skater?
(a) 0.10 m/s
(b) 0.20 m/s
(c) 0.70 m/s
(d) 1.4 m/s

Answer: A

Question. A body of weight 64 N is pushed with just enough force to start it moving across a horizontal floor and the same force continues to act afterwards. If the coefficients of static and dynamic friction are 0.6 and 0.4 respectively, the acceleration of the body will be (Acceleration due to gravity = g)
(a) g/6.4
(b) 0.64 g
(c) g/32
(d) 0.2 g

Answer: D

Question. A 60 kg weight is dragged on a horizontal surface by a rope upto 2 metres. If coefficient of friction is μ = 0.5, the angle of rope with the surface is 60° and g = 9.8 m/sec², then work done is
(a) 294 joules
(b) 315 joules
(c) 588 joules
(d) 197 joules

Answer: B

Question. Impulse equals
(a) rate of change of momentum
(b) change in momentum
(c) momentum multiplied by time
(d) rate of change of force

Answer: B

Question. Newton's first law of motion describes the
(a) energy
(b) work
(c) inertia
(d) moment of inertia

Answer: C

Question. An object will continue moving uniformly when
(a) the resultant force on it is increasing continuously
(b) the resultant force is at right angles to its rotation
(c) the resultant force on it is zero
(d) the resultant force on it begins to decrease

Answer: C

Question. Which motion does not require force to maintain it ?
(a) Uniform circular motion
(b) Elliptical motion
(c) Uniform straight line motion
(d) Projectile motion

Answer: C

Question. A ball is travelling with uniform translatory motion. This means that
(a) it is at rest.
(b) the path can be a straight line or circular and the ball travels with uniform speed.
(c) all parts of the ball have the same velocity (magnitude and direction) and the velocity is constant.
(d) the centre of the ball moves with constant velocity and the ball spins about its centre uniformly.

Answer: C

Question. External agencies like gravitational and magnetic forces ...X...exerts force on a body from a distance. Here, X refers to
(a) can
(b) cannot
(c) never
(d) None of these

Answer: A

Question. A reference frame attached to the earth
(a) is an inertial frame by definition
(b) cannot be an inertial frame because earth is revolving round the sun
(c) is an inertial frame because Newton's laws are applicable
(d) is an inertial frame because the earth is rotating about its own axis

Answer: B

Question. According to Galileo's experiment for a double inclined plane,if slope of second plane is zero and planes are smooth, then a ball is released from rest on one of the planes rolls down and move on the second plane ...X... distance. Here, X is
(a) zero
(b) infinite
(c) equal to length of first plane
(d) None of these

Answer: B

Question. Physical independence of force is a consequence of
(a) third law of motion
(b) second law of motion
(c) first law of motion
(d) all of these

Answer: C

Question. No force is required for
(a) an object moving in straight line with constant velocity
(b) an object moving in circular motion
(c) an object moving with constant acceleration
(d) an object moving in elliptical path.

Answer: A

Question. Inertia is the property of a body linked to tendency of a body
(a) to change its position
(b) to change its direction
(c) to change the momentum
(d) to resist any change in its state

Answer: D

Question. A man weighing 80 kg is standing on a trolley weighing 320 kg. The trolley is resting on frictionless horizontal rails. If the man starts walking on the trolley along the rails at a speed of one metre per second, then after 4 seconds, his displacement relative to the ground will be :
(a) 5 metres
(b) 4.8 metres
(c) 3.2 metres
(d) 3.0 metres

Answer: C

Question. A block of mass 4 kg rests on an inclined plane. The inclination to the plane is gradually increased. It is found that when the inclination is 3 in 5, the block just begins to slidedown the plane. The coefficient of friction between the block and the plane is
(a) 0.4
(b) 0.6
(c) 0.8
(d) 0.75.

Answer: D

Question. The minimum velocity (in ms^-1) with which a car driver must traverse a flat curve of radius 150 m and coefficient of friction 0.6 to avoid skidding is
(a) 60
(b) 30
(c) 15
(d) 25

Answer: B

Question. A rocket has a mass of 100 kg. Ninety percent of this is fuel. It ejects fuel vapors at the rate of 1 kg/sec with a velocity of 500 m/sec relative to the rocket. It is supposed that the rocket is outside the gravitational field. The initial upthrust on the rocket when it just starts moving upwards is
(a) zero
(b) 500 newton
(c) 1000 newton
(d) 2000 newton

Answer: B

Question. A circular road of radius r in which maximum velocity is v, has angle of banking
(a) tan^-1(v2/rg)
(b) tan^-1(rg/v2)
(c) tan^-1(v/rg)
(d) tan^-1(rg/v)

Answer: A

Question. A body of mass 1 kg moving with a uniform velocity of 1ms^-1 . If the value of g is 5ms^-2 , then the force acting on the frictionless horizontal surface on which the body is moving is
(a) 5 N
(b) 1 N
(c) 0 N
(d) 10N

Answer: A

Question. A trailer of mass 1000 kg is towed by means of a rope attached to a car moving at a steady speed along a level road. The tension in the rope is 400 N. The car starts to accelerate steadily. If the tension in the rope is now 1650 N, with what acceleration is the trailer moving ?
(a) 1.75 ms^–2
(b) 0.75 ms^–2
(c) 2.5 ms^–2
(d) 1.25 ms^–2

Answer: D

Question. A cricket ball of mass 150 g has an initial velocity u̅ = (3î + 4ĵ)ms^-1 and a final velocity v̅ = -(3î + 4ĵ)ms^-1 , after being hit. The change in momentum (final momentuminitial momentum) is (in kgms^–1)
(a) zero
(b) -(0.45î +0.6ĵ)
(c) -(0.9ĵ +1.2ĵ)
(d) -5(î +ĵ)î

Answer: C

Question. A person of mass 60 kg is inside a lift of mass 940 kg and presses the button on control panel. The lift starts moving upwards with an acceleration 1.0 m/s2. If g = 10 ms^–2, the tension in the supporting cable is
(a) 8600 N
(b) 9680 N
(c) 11000 N
(d) 1200 N

Answer: C

Question. A bag of sand of mass m is suspended by a rope. A bullet of mass m/20 is fired at it with a velocity v and gets embedded into it. The velocity of the bag finally is
(a) v/20 x 21
(b) 20v/21
(c) v/20
(d) v/21

Answer: D

Question. In the given figure, the pulley is assumed massless and frictionless. If the friction force on the object of mass m is f, then its acceleration in terms of the force F will be equal to
(a) (F - f ) /m
(b) (F/2 - f)/m
(c) F/m
(d) None of these

Answer: B

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 westward
(b) muscle force along southward
(c) frictional force along sotuh-west
(d) muscle force along south-west

Answer: C

Question. The coefficient of friction between the rubber tyres and the road way is 0.25. The maximum speed with which a car can be driven round a curve of radius 20 m without skidding is (g = 9.8 m/s²)
(a) 5 m/s
(b) 7 m/s
(c) 10 m/s
(d) 14 m/s

Answer: B

Question. A triangular block of mass M with angles 30°, 60°, and 90° rests with its 30°–90° side on a horizontal table. A cubical block of mass m rests on the 60°–30° side. The acceleration which M must have relative to the table to keep m stationary relative to the triangular block assuming frictionless contact is
(a) g
(b) g/√2
(c) g/√3
(d) g/√5

Answer: C

Question. A body with mass 5 kg is acted upon by a force F̅ = (-3î +4ĵ) N. If its initial velocity at t = 0 is v = (6î -12ĵ) ms^-1 , the time at which it will just have a velocity along the y-axis is
(a) never
(b) 10 s
(c) 2 s
(d) 15 s

Answer: B

Question. A 0.1 kg block suspended from a massless string is moved first vertically up with an acceleration of 5ms^-2 and then moved vertically down with an acceleration of 5ms^-2 . If T₁ and T₂ are the respective tensions in the two cases, then
(a) T₂ > T₁
(b) T₁ - T₂ = 1 N, if g = 10ms^-2
(c) T₁ -T₂ = 1kg f
(d) T₁ - T₂ = 9.8N, if g = 9.8 ms^-2

Answer: B

Question. A body of mass 1.0 kg is falling with an acceleration of 10 m/ sec². Its apparent weight will be (g = 10 m/sec²)
(a) 1.0 kg wt
(b) 2.0 kg wt
(c) 0.5 kg wt
(d) zero

Answer: D

Question. The coefficient of friction between two surfaces is 0.2. The angle of friction is
(a) sin^-1(0.2)
(b) cos^-1(0.2)
(c) tan^-1(0.1)
(d) cot -1(5)

Answer: D

Question. In the figure a smooth pulley of negligible weight is suspended by a spring balance. Weight of 1 kg f and 5 kg f are attached to the opposite ends of a string passing over the pulley and move with acceleration because of gravity, During their motion, the spring balance reads a weight of (52)
(a) 6 kg f
(b) less then 6 kg f
(c) more than 6 kg f
(d) may be more or less then 6 kg f

Answer: B

Question. A particle moves so that its acceleration is always twice its velocity. If its initial velocity is 0.1 ms^–1, its velocity after it has gone 0.1 m is
(a) 0.3 ms^–1
(b) 0.7 ms^–1
(c) 1.2 ms^–1
(d) 3.6 ms^–1

Answer: A

Question. If a stone is thrown out of an accelerated train, then acceleration of the stone at any instant depends on
(a) force acting on it at that instant
(b) acceleration of the train
(c) Both (a) & (b)
(d) None of these

Answer: A 

Question. Force depends on
(a) change in momentum
(b) how fast the change in momentum is brought about
(c) Both (a) & (b)
(d) None of these

Answer: C

Question. Newton’s second law measures the
(a) acceleration
(b) force
(c) momentum
(d) angular momentum

Answer: B

Question. The direction of impulse is
(a) same as that of the net force
(b) opposite to that of the net force
(c) same as that of the final velocity
(d) same as that of the initial velocity

Answer: A

Question. When a body is stationary
(a) there is no force acting on it
(b) the force acting on it is not in contact with it
(c) the combination of forces acting on it balances each other
(d) the body is in vacuum

Answer: C

Question. The acceleration of an astronaut is zero once he steps out of his accelerated spaceship in the intersteller space. this statement is in accordance with
(a) Newton’s second law of motion
(b) Newton's first law of motion
(c) Newton's third law of motion
(d) All of these

Answer: B

Question. Impulse is
(a) a scalar quantity
(b) equal to change in the momentum of a body
(c) equal to rate of change of momentum of a body
(d) a force

Answer: B

Question. Rocket engines lift a rocket from the earth surface, because hot gases with high velocity
(a) push against the air
(b) push against the earth
(c) react against the rocket and push it up
(d) heat up the air which lifts the rocket.

Answer: C

Question. China wares are wraped in straw of paper before packing. This is the application of concept of
(a) impulse
(b) momentum
(c) acceleration
(d) force

Answer: A

Question. A man is standing at the centre of frictionless pond of ice.How can he get himself to the shore?
(a) By throwing his shirt in vertically upward direction
(b) By spitting horizontally
(c) He will wait for the ice to melt in pond
(d) Unable to get at the shore

Answer: B

Question. A body of mass 32 kg is suspended by a spring balance from the roof of a vertically operating lift and going downward from rest. At the instant the lift has covered 20 m and 50 m, the spring balance showed 30 kg and 36 kg respectively. Then the velocity of the lift is
(a) decreasing at 20 m, and increasing at 50 m
(b) increasing at 20m and decreasing at 50 m
(c) continuously decreasing at a steady rate throughout the journey
(d) constantly increasing at constant rate throughout the journey.

Answer: B

Question. A 10 kg stone is suspended with a rope of breaking strength 30 kg-wt. The minimum time in which the stone can be raised through a height 10 m starting from rest is (Take g = 10N/ kg)
(a) 0.5 s
(b) 1.0 s
(c) √2/3 s
(d) 2 s

Answer: B

Question. A force F̅ = 8î - 6ĵ - 10k̂newton produces an acceleration of 1 ms^–2 in a body. The mass of the body is
(a) 10 kg
(b) 10 √2 kg
(c) 10 √3 kg
(d) 200 kg

Answer: B

Question. A player caught a cricket ball of mass 150 g moving at a rate of 20 m/s. If the catching process is completed in 0.1s, the force of the blow exerted by the ball on the hand of the player is equal to
(a) 150 N
(b) 3 N
(c) 30 N
(d) 300 N

Answer: C

Question. Starting from rest, a body slides down a 45º inclined plane in twice the time it takes to slide down the same distance in the absence of friction. The coefficient of friction between the body and the inclined plane is:
(a) 0.33
(b) 0.25
(c) 0.75
(d) 0.80

Answer: C 

Question. A rifle man, who together with his rifle has a mass of 100 kg, stands on a smooth surface and fires 10 shots horizontally. Each bullet has a mass 10 g and a muzzle velocity of 800 ms^–1. The velocity which the rifle man attains after firing 10 shots is
(a) 8 ms^-1
(b) 0.8 ms^-1
(c) 0.08ms^-1
(d) – 0.8 ms^-1

Answer: B

Question. In the system shown in figure, the pulley is smooth and massless, the string has a total mass 5g, and the two suspended blocks have masses 25 g and 15 g. The system is released from state l = 0 and is studied upto stage l'= 0 During the process, the acceleration of block A will be 

(a) constant at g/9
(b) constant at g/4
(c) increasing by factor of 3
(d) increasing by factor of 2

Answer: C

Question. For the arrangement shown in the Figure the tension in the string is [Given : tan^-1(0.8) = 39°] 

(a) 6 N
(b) 6.4 N
(c) 0.4 N
(d) zero.

Answer: D

Question. A block A of mass m₁ rests on a horizontal table. A light string connected to it passes over a frictionless pulley at the edge of table and from its other end another block B of mass m₂ is suspended. The coefficient of kinetic friction between the block and the table is μ_k. When the block A is sliding on the table, the tension in the string is 

Answer: B

Question. A spring of force constant k is cut into two pieces whose lengths are in the ratio 1 : 2. What is the force constant of the longer piece ?
(a) k/2
(b) 3k/2
(c) 2 k
(d) 3k

Answer: B

Question. A particle of mass 0.3 kg subject to a force F = – kx with k = 15 N/m . What will be its initial acceleration if it is released from a point 20 cm away from the origin ?
(a) 15 m/s²
(b) 3 m/s²
(c) 10 m/s²
(d) 5 m/s²

Answer: C

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 + mv²/1
(b) T-mv²/1
(c) Zero
(d) T

Answer: D

Question. An object at rest in space suddenly explodes into three parts of same mass. The momentum of the two parts are 2piˆ and pˆj . The momentum of the third part
(a) will have a magnitude p √3
(b) will have a magnitude p √5
(c) will have a magnitude p
(d) will have a magnitude 2p.

Answer: B

Question. A person with his hand in his pocket is skating on ice at the rate of 10m/s and describes a circle of radius 50 m. What is his inclination to vertical : (g = 10 m/sec²)
(a) tan^–1(½)
(b) tan^–1 (1/5)
(c) tan^–1 (3/5)
(d) tan^–1(1/10)

Answer: B

Question. When the road is dry and the coefficient of the friction is m, the maximum speed of a car in a circular path is 10 ms^–1. If the road becomes wet and μ'= μ/2, what is the maximum speed permitted? 
(a) 5 ms^–1
(b) 10 ms^–1
(c) 10 √2 ms^-1
(d) 5 √2 ms^-1

Answer: D

Question. Two pulley arrangements of figure given are identical. The mass of the rope is negligible. In fig (a), the mass m is lifted by attaching a mass 2m to the other end of the rope. In fig (b), m is lifted up by pulling the other end of the rope with a constant downward force F = 2mg. The acceleration of m in the two cases are respectively
(a) 3g, g
(b) g /3, g
(c) g /3, 2g
(d) g, g /3

Answer: B

Question. A block of mass 5 kg resting on a horizontal surface is connected by a cord, passing over a light frictionless pulley to a hanging block of mass 5 kg. The coefficient of kinetic friction between the block and the surface is 0.5. Tension in the cord is : (g = 9.8 m/sec²) 

(a) 49 N
(b) Zero
(c) 36.75 N
(d) 2.45 N

Answer: C

Question. A rocket of mass 5000 kg is to be projected vertically upward. The gases are exhausted vertically downwards with velocity 1000 ms–2 with respect to the rocket. What is the minimum rate of burning the fuel so as to just lift the rocket upwards against gravitational attraction ?
(a) 49 kg s^–1
(b) 147 kg s^–1
(c) 98 kg s^–1
(d) 196 kg s^–1

Answer: A

Question. A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table ?
(a) 12 J
(b) 3.6 J
(c) 7.2 J
(d) 1200 J

Answer: B

Question. A ball of mass 0.4 kg thrown up in air with velocity 30 ms ^-1 reaches the highest point in 2.5 second . The air resistance encountered by the ball during upward motion is
(a) 0.88 N
(b) 8800N
(c) 300 dyne
(d) 300 N.

Answer: A

Question. If the net external force on a body is ...X..., its acceleration is zero. Acceleration can be ...Y... only, if there is a net external force on the body. Here, X and Y refer to
(a) zero, zero
(b) zero, non-zero
(c) non-zero, zero
(d) non-zero, non-zero

Answer: B

Question. Newton’s second and third laws of motion lead to the conservation of
(a) linear momentum
(b) angular momentum
(c) potential energy
(d) kinetic energy

Answer: A

Question. We can derive Newton’s
(a) second and third laws from the first law
(b) first and second laws from the third law
(c) third and first laws from the second law
(d) All the three laws are independent of each other

Answer: C

Question. Swimming is possible on account of
(a) first law of motion
(b) second law of motion
(c) third law of motion
(d) newton's law of gravitation

Answer: C

Question. Which one of the following is not a force?
(a) Impulse
(b) Tension
(c) Thrust
(d) Air resistance

Answer: A

Question. A cannon after firing recoils due to
(a) conservation of energy
(b) backward thrust of gases produced
(c) Newton’s third law of motion
(d) Newton’s first law of motion

Answer: C 

Question. In which of the following cases, net force acting on the body is zero?
(a) A car moving with uniform velocity
(b) A book lying on the table
(c) Both (a) & (b)
(d) None of these

Answer: C

Question. Law of conservation of momentum follows from
(a) Newton's first law of motion
(b) Newton's second law of motion
(c) Newton's third law of motion
(d) Both (b) & (c)

Answer: D

Question. A large force is acting on a body for a short time. The impulse imparted is equal to the change in
(a) acceleration
(b) momentum
(c) energy
(d) velocity

Answer: B

Question. The same change in momentum about in ...X... time needs...Y... force applied. Here, X and Y refer to
(a) longer, lesser
(b) shorter, greater
(c) both (a) and
(b) (d) longer, greater

Answer: C

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

Answer: D

Question. Identify the correct statement.
(a) Static friction depends on the area of contact
(b) Kinetic friction depends on the area of contact
(c) Coefficient of kinetic friction does not depend on the surfaces in contact
(d) Coefficient of kinetic friction is less than the coefficient of static friction

Answer: D

Question. In an explosion, a body breaks up into two pieces of unequal masses. In this
(a) both parts will have numerically equal momentum
(b) lighter part will have more momentum
(c) heavier part will have more momentum
(d) both parts will have equal kinetic energy

Answer: A

Question. If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that
(a) linear momentum of the system does not change in time
(b) kinetic energy of the system does not change in time
(c) angular momentum of the system does not change in time
(d) potential energy of the system does not change in time

Answer: A

Question. A thin cushion of air maintained between solid surfaces in...X... is another effective way of ...Y... friction. Here, X and Y refer to
(a) relative motion, reducing
(b) motion, increasing
(c) relative motion, increasing
(d) None of these

Answer: 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 area of contact
(d) None of the these

Answer: A

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

Answer: D

Question. A jet engine works on the principle of
(a) conservation of mass
(b) conservation of energy
(c) conservation of linear momentum
(d) conservation of angular momentum

Answer: C

Question. A 1 kg block and a 0.5 kg block move together on a horizontal frictionless surface . Each block exerts a force of 6 N on the other. The block move with a uniform acceleration of 

(a) 3ms^-2
(b) 6ms^-2
(c) 9 ms^-2
(d) 12 ms^-2

Answer: D

Question. A horizontal force F is applied on back of mass m placed on a rough inclined plane of inclination q . The normal reaction N is (60)
(a) mg cosθ
(b) mgsin θ
(c) mg cosθ- Fcosθ
(d) mgcos θ + Fsin θ

Answer: D

Question. A ball of mass 400 gm is dropped from a height of 5 m. A boy on the ground hits the ball vertically upwards with a bat with an average force of 100 newton so that it attains a vertical height of 20 m. The time for which the ball remains in contact with the bat is (g = 10 m/s²)
(a) 0.12 s
(b) 0.08 s
(c) 0.04 s
(d) 12 s

Answer: A

Question. A ball mass m falls vertically to the ground from a height h₁ and rebounds to a height h₂. The change in momentum of the ball of striking the ground is
(a) m √2g(h₁ + h₂ )
(b) n √2g(m₁ +m₂ )
(c) mg(h₁ - h₂)
(d) m(√2gh₁ - 2gh₂)

Answer: D

Question. A bucket tied at the end of a 1.6 m long string is whirled in a vertical circle with constant speed. What should be the minimum speed so that the water from the bucket does not spill when the bucket is at the highest position?
(a) 4 m/sec
(b) 6.25 m/sec
(c) 16 m/sec
(d) None of the above

Answer: A

Question. A cane filled with water is revolved in a vertical circle of radius 4 meter and the water just does not fall down. The time period of revolution will be
(a) 1 sec
(b) 10 sec
(c) 8 sec
(d) 4 sec

Answer: D

Question. An object is resting at the bottom of two strings which are inclined at an angle of 120° with each other. Each string can withstand a tension of 20N. The maximum weight of the object that can be supported without breaking the string is
(a) 5 N
(b) 10 N
(c) 20 N
(d) 40 N

Answer: C

Question. Three blocks of masses m₁, m₂ and m₃ are connected by massless strings, as shown, on a frictionless table. They are pulled with a force T₃ = 40 N. If m₁ = 10 kg, m₂ = 6 kg and m₃ = 4kg, the tension T₂ will be

(a) 20 N
(b) 40 N
(c) 10 N
(d) 32 N

Answer: D

Question. A round uniform body of radius R, mass M and moment of inertia I rolls down (without slipping) an inclined plane making an angle θ with the horizontal. Then its acceleration is
(a) g sin θ/1 - MR² / I
(b) g sin θ/1+I/MR²
(c) g sin θ/1+MR²/I
(d) g sin θ/1-I/MR²

Answer: B

Question. A block of mass m is placed on a smooth wedge of inclination θ. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is acceleration due to gravity) will be
(a) mg/cos θ
(b) mg cos θ
(c) mg sin θ
(d) mg

Answer: A

Question. The coefficient of static friction, ms, between block A of mass 2 kg and the table as shown in the figure is 0.2. What would be the maximum mass value of block B so that the two blocks do not move? The string and the pulley are assumed to be smooth and massless. (g = 10 m/s²)
(a) 0.4 kg
(b) 2.0 kg
(c) 4.0 kg
(d) 0.2 kg

Answer: A

Question. The upper half of an inclined plane with inclination Φ is perfectly smooth while the lower half is rough. A body starting from rest at the top will again come to rest at the bottom if the coefficient of friction for the lower half is given by
(a) 2 cos Φ
(b) 2 sin Φ
(c) tan Φ
(d) 2 tan Φ

Answer: D

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) √gR
(b) √2gR
(c) √3gR
(d) √5gR

Answer: D

Question. The upper half of an inclined plane of inclination θ is perfectly smooth while lower half is rough. A block starting from rest at the top of the plane will again come to rest at the bottom, if the coefficient of friction between the block and lower half of the plane is given by
(a) μ = 2/tan θ
(b) μ = 2 tan θ
(c) μ = tan θ
(d) μ = 1/tan θ

Answer: B

Question. Block A of weight 100 kg rests on a block B and is tied with horizontal string to the wall at C. Block B is of 200 kg. The coefficient of friction between A and B is 0.25 and that between B and surface is 1/3 . The horizontal force F necessary to move the block B should be (g = 10 m/s²)
(a) 1050 N
(b) 1450 N
(c) 1050 N
(d) 1250 N

Answer: D

Question. An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^–1 and the second part of mass 2 kg moves with speed 8 ms^–1. If the third part flies off with speed 4 ms^–1 then its mass is
(a) 5 kg
(b) 7 kg
(c) 17 kg
(d) 3 kg

Answer: A 

Question. On a smooth plane surface (figure) two block A and B are accelerated up by applying a force 15 N on A. If mass of B is twice that of A, the force on B is 

(a) 30 N
(b) 15 N
(c) 10 N
(d) 5 N

Answer: C

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

Answer: B

Question. The linear momentum p of a body moving in one dimension varies with time according to the equating P = a + bt² where a and b are positive constants. The net force acting on the body is
(a) proportional to t²
(b) a constant
(c) proportional to t
(d) inversely proportional to t

Answer: C

Question. Two particles of masses m and M (M > m ) are connected by a cord that passes over a massless, frictionless pulley. The tension T in the string and the acceleration a of the particles is

Answer: B

Question. A block is kept on a frictionless inclined surface with angle of inclination ‘ α ’ . The incline is given an acceleration ‘a’ to keep the block stationary. Then a is equal to 
(a) g cosec α
(b) g / tan α
(c) g tan α
(d) g

Answer: C

Question. Consider a car moving on a straight road with a speed of 100 m/s . The distance at which car can be stopped is [μ_k = 0.5]
(a) 1000 m
(b) 800 m
(c) 400 m
(d) 100 m

Answer: A

Question. A motor cycle is going on an overbridge of radius R. The driver maintains a constant speed. As the motor cycle is ascending on the overbridge, the normal force on it
(a) increases
(b) decreases
(c) remains the same
(d) fluctuates erratically

Answer: A

Question. An open topped rail road car of mass M has an initial velocity v0 along a straight horizontal frictionless track. It suddenly starts raising at time t = 0. The rain drops fall vertically with velocity u and add a mass m kg/sec of water. The velocity of car after t second will be (assuming that it is not completely filled with water) 

Answer: B

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) kinetic friction
(b) static friction
(c) limiting friction
(d) None of these

Answer: B

Question. Which one of the following motions on a smooth plane surface does not involve force?
(a) Accelerated motion in a straight line
(b) Retarded motion in a straight line
(c) Motion with constant momentum along a straight line
(d) Motion along a straight line with varying velocity

Answer: C

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

Answer: D

Question. Frictional force that opposes relative motion between surfaces in contact is called ...X... and denoted by ...Y.... Here, X and Y refer to
(a) static friction, fs
(b) kinetic friction, fs
(c) kinetic friction, fk
(d) static friction, fk

Answer: C

Question. What are the effects if force is acting on a moving body in a direction perpendicular to the direction of motion?
(a) The speed changes uniformly
(b) The acceleration changes uniformly
(c) The direction of motion changes
(d) All of these

 Answer: C

Question. When a car moves on a level road, then the centripetal force required for circular motion is provided by ________
(a) weight of the car
(b) normal reaction
(c) component of friction between the road & tyres along the surface.
(d) All of these

Answer: C

Question. An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^–1 and the second part of mass 2 kg moves with speed 8 ms^–1. If the third part flies off with speed 4 ms^–1 then its mass is
(a) 5 kg
(b) 7 kg
(c) 17 k
(d) 3 kg

Answer: A

Question. Which of the following forces does not act on a body moving in uniform circular motion?
(a) Centripetal force
(b) Weight of the body
(c) Normal reaction
(d) Force of friction

Answer: A

Question. A cyclist taking turn bends inwards while a car passenger taking the same turn is thrown outwards. The reason is
(a) car is heavier than cycle
(b) car has four wheels while cycle has only two
(c) difference in the speed of the two
(d) cyclist has to counteract the centrifugal force while in the case of car only the passenger is thrown by this force

Answer: D 

Question. A car takes a circular turn with a uniform speed u. If the reaction at inner and outer wheels be denoted by R₁ and R₂,then
(a) R₁ = R₂
(b) R₁ < R₂
(c) R₁ > R₂
(d) None of these

Answer: B

Question. A ball is thrown up at an angle with the horizontal. Then the total change of momentum by the instant it returns to ground is
(a) acceleration due to gravity × total time of flight
(b) weight of the ball × half the time of flight
(c) weight of the ball × total time of flight
(d) weight of the ball × horizontal range

Answer: C

Question. A cyclist bends while taking turn in order to
(a) reduce friction
(b) provide required centripetal force
(c) reduce apparent weight
(d) reduce speed

Answer: B

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) in the hand of his brother
(b) slightly away from the hand of his brother in the direction of motion of the train
(c) slightly away from the hand of his brother opposite to the direction of motion of the train
(d) None of the above

Answer: B

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) MV
(b) 1.5 MV
(c) 2 MV
(d) zero

Answer: C

Question. The net force on a rain drop falling down with a constant speed is ________
(a) weight of drop W
(b) viscous drag of air F
(c) W + F + force of buoyany
(d) zero

Answer: D

Question. A bridge is in the from of a semi-circle of radius 40m. The greatest speed with which a motor cycle can cross the bridge without leaving the ground at the highest point is (g = 10 m s^–2) (frictional force is negligibly small)
(a) 40 m s^–1
(b) 20 m s^–1
(c) 30 m s^–1
(d) 15 m s^–1

Answer: B

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) MV
(b) 1.5 MV
(c) 2 MV
(d) zero

Answer: C

Question. A ball is travelling with uniform translatory motion. This means that
(a) it is at rest
(b) the path can be a straight line or circular and the ball travels with uniform speed
(c) all parts of the ball have the same velocity (magnitude and direction) and the velocity is constant
(d) the centre of the ball moves with constant velocity and the ball spins about its centre uniformly

Answer: C

Question. A bullet of mass m is fired from a gun of mass M. The recoiling gun compresses a spring of force constant k by a distance d. Then the velocity of the bullet is 
(a) kd√M/m
(b) d/M√km
(c) d/m√kM
(d) kM/m√d

Answer: C

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: A

Question. A body under the action of a force F̅ = 6î - 8ĵ + 10k̂, acquires an acceleration of 1 m/s2. The mass of this body must be
(a) 10 kg
(b) 20 kg
(c) 10 √2 kg
(d) 2 √10 kg

Answer: C

Question. Two bodies of masses m and 4m are moving with equal kinetic energies. The ratio of their linear momenta will be
(a) 1 : 4
(b) 4 : 1
(c) 1 : 2
(d) 2 : 1

Answer: C 

Question. A metre scale is moving with uniform velocity. This implies
(a) the force acting on the scale is zero, but a torque about the centre of mass can act on the scale
(b) the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero
(c) the total force acting on it need not be zero but the torque on it is zero
(d) neither the force nor the torque need to be zero

Answer: B

Question. Conservation of momentum in a collision between particles can be understood from
(a) Conservation of energy
(b) Newton's first law only
(c) Newton's second law only
(d) both Newton's second and third law

Answer: D

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) 1.2 m
(b) 0.6 m
(c) zero
(d) 0.4 m

Answer: D

Question. A heavy uniform chain lies on horizontal table top. If the coefficient of friction between the chain and the table surface is 0.25, then the maximum fraction of the length of the chain that can hang over one edge of the table is
(a) 20%
(b) 25%
(c) 35%
(d) 15%

Answer: A

Question. Three blocks with masses m, 2 m and 3 m are connected by strings as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force on the block of mass 2m? (g is the acceleration due to gravity)

(a) 2 mg
(b) 3 mg
(c) 6 mg
(d) zero

Answer: D

Question. A car is moving in a circular horizontal track of radius 10 m with a constant speed of 10 m/s. A bob is suspended from the roof of the car by a light wire of length 1.0 m. The angle made by the wire with the vertical is
(a) 0°
(b) π/3
(c) π/6
(d) π/4

Answer: D

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) 2ma/g + a
(b) 2ma/g - a
(c) ma/g + a
(d) ma/g - a

Answer: A

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) 24 Ns
(b) 20 Ns
(c) 12 Ns
(d) 6 Ns

Answer: C

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) g(1 - gμ)/g 
(b) 2gμ/3
(c) g(1 -2μ)/3
(d) g(1 -2μ)/2

Answer: C

Question. Two stones of masses m and 2 m are whirled in horizontal circles, the heavier one in radius r/2 and the lighter one in radius r. The tangential speed of lighter stone is n times that of the value of heavier stone when they experience same centripetal forces. The value of n is : 
(a) 3
(b) 4
(c) 1
(d) 2

Answer: D

Question. A body of mass 5 kg explodes at rest into three fragments with masses in the ratio 1 : 1 : 3. The fragments with equal masses fly in mutually perpendicular directions with speeds of 21 m/s. The velocity of heaviest fragment in m/s will be
(a) 7 √2
(b) 5 √2
(c) 3 √2
(d) 2

Answer: A

Question. A car of mass m starts from rest and acquires a velocity along east, v̅ = vî (v > 0) in two seconds. Assuming the car moves with uniform acceleration, the force exerted on the car is
(a) mv/2 eastward and is exerted by the car engine
(b) mv/2 eastward and is due to the friction on the tyres exerted by the road
(c) more than mv/2 eastward exerted due to the engine and overcomes the friction of the road
(d) mv/2 exerted by the engine

Answer: B

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: A

Question. On a banked road, which force is essential to provide the necessary centripetal force to a car to take a turn while driving at the optimum speed?
(a) Component of normal reaction
(b) Component of frictional force
(c) Both (a) & (b)
(d) None of these

Answer: A

Question. If two masses (M & m) are connected on a horizontal plane and a force is applied on the combination, then the tension T depends on
(a) the force applied on the system
(b) whether force is applied on M or m
(c) both (a) and (b)
(d) Can’t be predicted.

Answer: B

Question. A person sitting in an open car moving at constant velocity throws a ball vertically up into air. The ball falls
(a) outside the car
(b) in the car ahead of the person
(c) in the car to the side of the person
(d) exactly in the hand which threw it up

Answer: D

Question. A particle revolves round a circular path. The acceleration of the particle is inversely proportional to
(a) radius
(b) velocity
(c) mass of particle
(d) both (b) and (c)

Answer: A

Each question contains
STATEMENT-1 and STATEMENT-2. Choose the correct answer
(a) Statement -1 is false, Statement-2 is true
(b) Statement -1 is true, Statement-2 is true; Statement -2 is a correct explanation for Statement-1
(c) Statement -1 is true, Statement-2 is true; Statement -2 is not a correct explanation for Statement-1
(d) Statement -1 is true, Statement-2 is false

Question. Statement -1 : The two bodies of masses M and m (M > m) are allowed to fall from the same height if the air resistance for each be the same then both the bodies will reach the earth simultaneously.
Statement -2 : For same air resistance, acceleration of both the bodies will be same.

Answer: A

Question. Statement -1 : On a rainy day, it is difficult to drive a car or bus at high speed.
Statement -2 : The value of coefficient of friction is lowered due to wetting of the surface.

Answer: B

Question. Statement -1 : The work done in bringing a body down from the top to the base along a frictionless incline plane is the same as the work done in bringing it down the vartical side.
Statement -2 : The gravitational force on the body along the inclined plane is the same as that along the vertical side.

Answer: D