# MCQs for Science Class 9 with Answers Chapter 9 Force And Laws Of Motion

Students of class 9 Science should refer to MCQ Questions Class 9 Science Force And Laws Of Motion with answers provided here which is an important chapter in Class 9 Science NCERT textbook. These Multiple Choice Questions have been prepared based on the latest CBSE and NCERT syllabus and examination guidelines for Class 9 Science. The following MCQs can help you to practice and get better marks in the upcoming class 9 Science examination

Question. Inertia depends upon –
(A) acceleration of the body
(B) velocity of the body
(C) shape of the body
(D) mass of the body

D

Question. Which of the following has largest inertia?
(A) A pin
(B) An ink pot

D

Question. Newton’s second law of motion-
(A) defines force
(B) defines inertia
(C) gives measure of force
(D) none of these

C

Questions. Newton’s second law of motion is –
(A) qualitative
(B) quantitative
(C) both qualitative and quantitative
(D) neither qualitative nor quantitative

B

Questions. Forces of action and reaction are:
(A) equal and in same direction
(B) equal and in opposite direction
(C) unequal and in same direction
(D) unequal and opposite.

B

Questions. Forces of action and reaction –
(A) one after the other on same body
(B) simultaneously on same body
(C) one after the other on different bodies
(D) simultaneously on different bodies

D

Questions. If the action and reaction were to act on the same body-
(A) the resultant would be zero
(B) the body would not move at all
(C) both A and B are correct
(D) neither A nor B is correct

C

Questions. Consider two spring balances hooked as shown in the figure. We pull them in opposite directions. If the reading shown by A is 1.5 N, the reading shown by B will be – A B
(A) 1.5 N
(B) 2.5 N
(C) 3.0 N
(D) zero

A

Questions. A Diwali rocket is ejecting 0.05 kg of gases per second at a velocity of 400 ms–1. The accelerating force on the rocket is:
(A) 20 dyne
(B) 20 Newton
(C) 20 kg wt.
(D) sufficient data not given

B

Questions. The forces of action and reaction have …………….. magnitude but ……………. direction-
(A) same, same
(B) same, opposite
(C) opposite, same
(D) opposite, opposite

B

Question. A body of mass 20 kg moves with an acceleration of 2ms–2. The rate of change of momentum in S.I. unit is –
(
A) 40
(B) 10
(C) 4
(D) 1

A

Question. 9.8 N is equal to-
(A) 1 kgf
(B) 1 kgwt
(C) A and B both
(D) Neither A nor B

C

Question. Newton’s first law of motion is –
(A) qualitative
(B) quantitative
(C) both qualitative and quantitative
(D) neither qualitative nor quantitative

A

Question. When a bus starts suddenly the passengers standing on it, lean backwards in the bus. This is an example of –
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law
(D) none of Newton’s law

A

Question. If A and B are two objects with masses 10 kg and 30 kg respectively then :
(A) A has more inertia than B
(B) B has more inertia than A
(C) A and B have the same inertia
(D) none of the two have inertia

B

Question. An iron ball and aluminium ball has same mass:
(A) inertia of iron is greater than aluminium
(B) both the ball have same inertia
(C) inertia of iron is less than that of Aluminium
(D) none of these

B

Question. A bullet of mass 0.01 kg is fired from a gun weighing 5.0 kg. If the initial speed of the bullet is 250 m/s, calculate the speed with which the gun recoils-
(A) – 0.50 m/s
(B) – 0.25 m/s
(C) + 0.05 m/s
(D) + 0.25 m/s

A

Question. A man is standing on a boat in still water. If he walks towards the shore the boat will –
(A) move away from the shore
(B) remain stationary
(C) move towards the shore
(D) sink

A

Question. A bullet in motion hits and gets embedded in a solid resting on a frictionless table. What is conserved ?
(A) Momentum and K.E.
(B) Momentum alone
(C) K.E. alone
(D) None of these

B

Question. Choose correct statement-
(A) Action and reaction forces act on same object.
(B) Action and reaction forces act on different objects.
(C) A and B both are possible.
(D) Neither A nor B is correct.

B

Question. Gram weight is a unit of-
(A) mass
(B) weight
(C) A and B both
(D) neither A nor B

B

Question. A body of mass 5 kg undergoes a change in speed from 20 m/s to 0.20 m/s. The momentum-
(A) increases by 99 kgm/s
(B) decreases by 99 kgm/s
(C) increases by 101 kgm/s
(D) decreases by 101 kgm/s

B

Question. Newton used, ‘quantity of motion’ for-
(A) momentum
(B) force
(C) acceleration due to gravity
(D) none of these

A

Question. When a bus starts suddenly the passengers standing on it, lean backwards in the bus. This is an example of –
(A) Newton’s first law
(B) Newton’s second law
(C) Newton’s third law
(D) none of Newton’s law

A

Question. Momentum measures amount of ………… in a body-
(A) inertia
(B) motion
(C) velocity
(D) acceleration

B

Question. Force measures rate of change of ……….. a body
(A) mass
(B) inertia
(C) velocity
(D) momentum

D

Question. Inertia of rest is the property by virtue of which the body is unable to change by itself:
(A) the state of rest only
(B) the state of uniform linear motion
(C) the direction of motion only
(D) the steady state of rest

D

Question. A body of mass M strikes against wall with a velocity v and rebounds with the same velocity. Its change in momentum is –
(A) zero(B) Mv(C) –Mv
(B) Mv
(C) –Mv
(D) –2 Mv

D

Question. First law of motion defines-
(A) inertia
(B) force
(C) both inertia and force
(D) neither inertia nor force

C

Question. If a moving ball A collides with another moving ball B, then
(A) momentum of A = momentum of B
(B) (momentum A + momentum of B) before collision = (momentum A + momentum of B) after collision
(C) neither A nor B
(D) A or B both are possible