MCQ PRACTICE

Welcome to your Ncert - class 9- science - Chapter 8 – Force and Laws of Motion 1

An object maintains its motion under the continuous application of ________force

A balanced

A strong

An unbalanced

A weak

None

Principle of rocket is based on Newton's ......... law of motion.

First

Second

Third

None

What happens when some children try to push a box on a rough floor?

The box will move regardless of the force given

The box moves with a little force

The box does not move with a small force

None of these

None

Statement A: Gravitational force is the weakest force in nature

Statement B: Electrostatic force is the example of non – contact force

Which of the above two statement is true?

statement B

both the statement a and b

neither statement A nor B

statement A

None

Match the following with correct response.

(1) Action and reaction

(2) Magnitude of force

(3) Momentum

(4) Resultant of balanced force

(A) No acceleration

(B) Newton’s second law

(D) Scalar quantity

1-D, 2-A, 3-C, 4-B

1-C, 2-B, 3-D, 4-A

1-A, 2-C, 3-B, 4-D

1-B, 2-D, 3-A, 4-C

None

Which of the following uses the principle of conservation of momentum?

Ballon moves upwards when burst or when air is expelled out of it

Motion of rockets and jet engines

Gun recoils after firing

All of these

None

A bullet weighing 50 gram leaves the gun with a velocity of 30m/s.the ratio of their momentum is:

1:3

1:1

1:2

2:1

None

Match the following with correct response.

(1) Cause of acceleration

(2) Quantitative measure of inertia

(3) powder applied on carom board

(4) Tyres of vehicles made Rough

(A) Mass

(B) Increases friction

(D) Force

1-B, 2-D, 3-A, 4-C

1-C, 2-B, 3-D, 4-A

1-D, 2-A, 3-C, 4-B

1-A, 2-C, 3-B, 4-D

None

Choose the correct statement from the following:

Weightlessness of an astronaut moving in a satellite is a situation of

Zero mass

Free fall

Zero g

No gravity

None

10.

When a toothpaste tube is squeezed, it's shape changes. The force responsible for this is an example of _______.

Unbalanced force

Balanced force

Centripetal force

Tangential force

None

11.

A truck is moving on a frictionless surface with uniform velocity of 10ms −1 . A leak occurs in the water tank of the truck at the rate of 2kg −1 What is the speed of truck after 50 s, if the mass of truck is 100kg and mass of water in the truck initially was 100kg?

5ms −1

10ms −1

20ms −1

None of these

None

12.

Identify the incorrect statement.

The tension of a string always pulls a body.

Frictional force always acts parallel to the surface of contact.

The spring force always pushes a body.

The weight of a body always acts towards the centre of the Earth.

None

13.

If an object experiences a net zero unbalanced force, then the body

cannot remain at rest

moves with a constant velocity

will always remain at rest

can be accelerated

None

14.

How much force acts on body whose momentum is constant (i.e. = constant)?

2p/t

None

p/2t

Zero

None

15.

What is the action reaction pair when we walk on the floor?

Air resistance, force applied by road on your feet

Your feet exerts force on road, road reverts equal force back,

None of these

Air resistance, muscular force

None

16.

What is the product of force and the time for which force acts known as?

Inertia

Impulse of force

Momentum

Acceleration

None

17.

What is the direction of the unbalanced force acting on a body which is accelerating in a straight line?

In the direction opposite to the motion of the body.

None of these.

In the direction perpendicular to the motion of the body.

In the direction of motion of the body.

None

18.

A hockey player pushes the ball on the ground. Why does the ball come to rest after travelling a certain distance?

No unbalanced force acts on the ball.

The ball moves only when pushes.

The player stops pushing the ball.

The opposing force of friction acts on the ball.

None

19.

Ayush hits a cricket ball which than rolls of a level ground after covering a short distance, the ball comes to rest. The ball slows to a stop because

There is no unbalanced force on the ball so the ball would want to come to rest.,

Velocity is proportional to the force exerted on the ball.

Ayush did not hit the ball hard enough

There is a force on the ball opposing the motion

None

20.

Match the following with correct response.

(1) Cart pulled by a horse

(2) Backward jerk

(3) Sole of shoe worn out

(4) Recoiling of gun

(A) Friction

(B) Newton’s III law of motion

(D) Law of inertia

1-B, 2-D, 3-A, 4-C

1-D, 2-A, 3-C, 4-B

1-C, 2-B, 3-D, 4-A

1-A, 2-C, 3-B, 4-D

None

Chapter 7 - Motion

Chapter 8-Force and Law of Motion

Chapter 9 - Gravitational

Chapter 10 - Work and Energy

CHAPTER 11 - SOUND

Curriculum

NCERT - Class 9 - Science - PHYSICS

Chapter 7 - Motion

Chapter 8-Force and Law of Motion

Chapter 9 - Gravitational

Chapter 10 - Work and Energy

CHAPTER 11 - SOUND

MCQ PRACTICE – 1