JEE Physics Force and Laws of Motion MCQs Set A

Question. An external influence which changes or tends to change the state of rest or uniform motion of body or its dimensions is called :
(a) momentum 
(b) force
(c) moment of force
(d) pressure

Answer : B

Question. Equal and opposite forces acting on a body which do not change its state of rest or uniform motion are called:
(a) like parallel forces
(b) unlike parallel forces
(c) balanced forces
(d) all the above

Answer : C

Question. The unequal and opposite forces acting on a body, which change its state of rest or uniform motion are called:
(a) unbalanced forces
(b) unlike parallel forces
(c) like parallel forces
(d) all the above

Answer : B

Question. Force of friction always acts in the direction:
(a) of applied force
(b) opposite to the direction of applied force
(c) at right angles to the direction of applied force
(d) none of the above

Answer : B

Question. When balanced forces act on a body, the body:
(a) must remain in its state of rest
(b) must continue moving with uniform velocity, if already in motion
(c) must experience some acceleration
(d) both (a) and (b)

Answer : A

Question. When unbalanced forces act on a body, the body:
(a) must move with uniform velocity
(b) must remain at rest
(c) must experience acceleration
(d) must move in a curved path

Answer : C

Question. If no external force acts on a body, it will :
(a) move with more speed
(b) change its shape
(c) break into pieces
(d) either remain in its state of rest or in uniform motion.

Answer : D

Question. If a body is allowed ti freely fall from a height, its speed increases continuously. It is because:
(a) air does not exert frictional force
(b) magnetic force of earth increases its speed
(c) gravitational force of earth increases its speed
(d) pressure of air forces it downward

Answer : C

Question. A force of magnitude' F' acts on a body of mass 'm'. The acceleration of the body depends upon:
(a) volume of body
(b) density of body
(c) area of body
(d) mass of body

Answer : D

Question. Force remaining constant, if the mass of body increases, its acceleration is likely to :
(a) increase
(b) remain same
(c) decrease
(d) sometimes increases and sometimes decreases

Answer : C

Question. A force F produces an acceleration 'a' in a body.
The same force produces and acceleration 4a in another body. The mass of other body is :
(a) four times the mass of first body
(b) four times less the mass of other body
(c) mass does not play role
(d) none of the above

Answer : B

Question. When a running motorbike accelerates suddenly, the pillion rider has a tendency to fall backward. This is an example of:
(a) Newton's first law of motion
(b) Newton's second law of motion
(c) Newton's third law of motion
(d) Newton's law of gravitation of motion

Answer : A

Question. A force F acts on a stationary body for the time t. The distance covered by the body 'S' will be proportional to:
(a) t
(b) 1/t
(c) t²
(d) 1/t²

Answer : C

Question. The impact which a body can produce due to the combined effect of mass and velocity is called:
(a) momentum
(b) force
(c) moment of force
(d) pressure

Answer : A

Question. The SI unit of momentum is :
(a) newton
(b) newton-second
(c) dyne
(d) dyne-second

Answer : B

Question. The tendency of a body to continue in its state of rest or uniform motion, even on the application of external force is called:
(a) force
(b) momentum
(c) inertia
(d) impulse

Answer : C

Question. A body will continue in its state of rest or uniform motion in a straight line, unless acted by some external force. The statement represents :
(a) Newton's second law of motion
(b) Newton's first law of motion
(c) Newton's third law of motion
(d) Law of conservation of momentum

Answer : B

Question. The magnitude of inertia of a body is determined by its:
(a) mass
(b) weight
(c) velocity
(d) acceleration

Answer : A

Question. Momentum is a:
(a) vector quantity
(b) scalar quantity
(c) fundamental quantity
(d) none of the above

Answer : A

Question. A body P has mass 2 m and velocity 5 v. Another body Q has mass 8 m and velocity 1.25 v. The ratio of momentum of P and Q is :
(a) 2 : 1
(b) 1 : 1
(c) 1 : 2
(d) 3 : 2

Answer : B

Question. The magnitude of a physical quantity is 8.5 Ns. The physical quantity is :
(a) force
(b) momentum
(c) pressure
(d) moment of force

Answer : B

Question. There is a rubber ball and a stone ball of same size. If both balls are at rest:
(a) rubber ball has more inertia than stone ball
(b) stone ball has more inertia than rubber ball
(c) both have same inertia
(d) none of the above.

Answer : B

Question. When we vigorously a shake branch of a tree, some leaves get detached. It is due to the:
(a) inertia of rest
(b) inertia of motion
(c) some leaves are loosely held by the branch
(d) none of the above.

Answer : A

Question. When the driver of a fast moving car suddenly applies brakes, the passengers in the car:
(a) fall backward
(b) fall forward
(c) are not affected
(d) none of the above.

Answer : B

Question. Which is the incorrect statement? A spaceship continues moving in space with uniform speed because:
(a) no force of friction due to air acts on it
(b) its mass is zero in space
(c) no force of gravitation acts on it
(d) no force of friction due to earth acts on it

Answer : B