# MCQ Class 9 Science Chapter 9 Force And Laws Of Motion

Please refer to the MCQ Questions for Class 9 Science Chapter 9 Force And Laws Of Motion. The following Force And Laws Of Motion Class 9 Science MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 9. Our experts have designed MCQ Questions for Class 9 Science with Answers for all chapters in your NCERT Class 9 Science book.

## Force And Laws Of Motion Class 9 MCQ Questions with Answers

See below Force And Laws Of Motion Class 9 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. If the slope of distance–time graph increases with time, it indicates that the velocity of the body is
a. increasing with time.
b. decreasing with time.
c. remains constant.
d. uniform.

A

Question. An unbalanced force acting on a body does not produce an effect of
a. change in speed of the body.
b. change in shape of the body.
c. change in direction of motion of the body.
d. change in state of rest of the body.

B

Question. If a number of forces acting on a body change velocity of the body. The forces are
a. parallel.
b. unbalanced.
c. balanced.
d. inclined.

B

Question. The inertia of an object tends to cause an object
a. to increase its speed.
b. to decrease its speed.
c. to resist a change in its state of motion.
d. to decelerate due to friction.

C

Question. Impulse of a force is measured by
a. F × t
b. F/t
c. F + t
d. F – t

A

Question. Which is a wrong statement?
a. Action and reaction forces occur in pairs only.
b. Action and reactions forces are always equal in magnitude.
c. Action and reaction forces act on different bodies.
d. Action and reaction forces act in the same direction.

D

Question. The inertia of a moving body depends on
a. momentum of the object.
b. speed of the object.
c. mass of the object.
d. shape of the object.

C

Question. Inertia is defined by
a. Newton’s first law.
b. Newton’s second law.
c. Newton’s third law.
d. none of these.

Question. Newton’s third law
a. defines the force qualitatively.
b. defines the force quantitatively.
c. explains the way the force acts on it.
d. gives the direction of force.

B

Question. A force causes an acceleration of 10 m/s in a body of mass 500 kg. The acceleration caused by the same force in a body of mass 5 kg is
a. 10 m/s2
b. 1 m/s2
c. 0.1 m/s2
d. 100 m/s2

B

Question. When a rubber ball is pressed by a person in his hands, its shape changes. This is because
a. unbalanced forces act on the ball.
b. balanced forces act on the ball.
c. frictional forces act on the ball.
d. gravitational forces act on the ball.

B

Question. A body whose momentum is constant must have constant
a. force.
b. velocity.
c. acceleration.
d. all of these.

B

Question. Choose the wrong statement.
a. Unit of force is newton.
b. Force changes the shape of a body.
c. Force is always conserved .
d. Force is a vector quantity.

C

Question. Balanced forces may a body.
a. move
b. accelerate
c. retard
d. deform

D

Question. The SI unit of impulse is
a. kg ms–1
b. kg ms–2
c. N
d. N/s

A

Question. If a constant force acts on a body initially at rest, the distance moved by the body in time t is proportional to
a. t
b. t2
c. t3
d. t4

B

Question. One newton is equal to
a. 105 dyne
b. 10 kg ms–2
c. 103 dyne
d. 100 kg m–2

A

Question. The velocity of a body of mass 20 kg decreases from 20 m/s to 5 m/s in a distance of 100 m. Force on the body is
a. – 27.5 N
b. – 47.5 N
c. – 37.5 N
d. – 67.5 N

C

Question. The force required to produce an acceleration of 2 m/s2 in a body of mass 0.8 kg is
a. 1.6 N
b. 2.6 N
c. 0.16 N
d. 16 N

A

Question. The acceleration produced in a body by a force of given magnitude depends on
a. size of the body.
b. shape of the body.
c. mass of the body.
d. none of these.

C

Question. Action and reaction act on
a. different bodies in opposite direction.
b. same body in opposite directions.
c. different bodies but in same direction.
d. same body in same direction.

B

Question. If a boy pushes a wall with a force of 10 N towards east, then the force exerted by the wall on the boy is
a. 10 N towards east.
b. 10 N towards west.
c. 20 N towards west.
d. 20 N towards east.

A

Question. The principle of conservation of linear momentum states that the linear momentum of a system
a. cannot be changed.
b. cannot remain constant.
c. can be changed if only internal force acts.
d. can be changed only if eternal force acts.

D

Question. Which of the following is not is not an example of Newton’s third law of motion?
a. A cricket player lowering his hand while catching a ball
b. Walking on a floor
c. Rebounding of a rubber ball
d. Flight of a jet

A

Question. Which is not the type of inertia?
a. Inertia of rest
b. Inertia of motion
c. inertia of direction
d. Inertia of force

D

Question. The linear momentum of a body of mass 5 kg moving with a velocity of 2 m/s is
a. 0.1 kgm/s
b. 10 kgms
c. 10 m/s
d. 10 kg m/s

D

Question. The acceleration produced in a body of mass 2 kg, if the force applied on it is 15 N is
a. 7.5 m/s
b. 7.5 m/s2
c. 0.75 m/s2
d. 30 m/s2

B

Question. A person jumping out of a moving bus may fall forward because of
a. Inertia of rest.
b. Inertia of motion.
c. inertia of direction.
d. none of these.

B

Question. External forces are
a. always balanced.
b. never balanced.
c. may or may not be balanced.
d. none of these.