Effects of Friction

Q. A ball rolling on ground slows down primarily because of:

1. gravitational force
2. magnetic force
3. frictional force
4. spring force

Q.

Friction causes wear and tear of the surfaces in contact.

1. True
2. False

Q. While we walk, friction between the ground and the feet prevents us from__.

1. running
2. jumping
3. slipping
4. walking

Q.

How is friction between coins and carrom board affected when some powder is sprinkled on the carrom board?

1. It increases little

2. It increases to a large extent

3. It doesn't change

4. It decreases

Q. Statement I: When a brick is pushed on a soft carpet, there is friction only because of uneven interlocking of surfaces.
Statement II: When a brick is pushed on a soft carpet, there is friction because carpet has a soft surface and can undergo deformations.

1. Only statement I is correct.
2. Only statement II is correct.
3. Both statements I and II are correct.
4. Neither statement I nor statement II is correct.

Q. The sharp tip of a pencil becomes blunt after writing for a while due to friction.

1. True
2. False

Q. Which of the following factors are responsible for friction?

1. Adhesion or stickiness
2. Plowing effect
3. Surface roughness
4. Density of the object

Q. What is friction

Q.

A ball is rolled along the surface. The ball comes to a stop after some time. Which force is responsible for stopping the motion of the ball?

1. All of these

2. Air resistance

3. Gravitational pull

4. Frictional force

Q. Increasing friction helps in

1. better grip.
2. reducing heating of components.
3. less wear and tear
4. slipping easily.

Q. Rubber bushes are fixed at the bottom of ladders, walking sticks and furnitures to ___.

1. avoid damage to equipments
2. avoid damage to surface
3. avoid slipping
4. prevent electric shock

Q.

In which of the following cases, friction is a friend?

1. Heating of a working mixer

2. Wearing of machines

3. Using pen for writing

4. Noisy machines

Q. A car being driven on plain road doesn't slip because:

1. the driver drives properly.
2. friction prevents slipping.
3. brakes are applied consistently.
4. the engine doesn't let the car slip.

Q. Plowing effect causes wear and tear of surface.

1. False
2. True

Q. If there is no friction between a ball and surface, the ball moving in the surface will

1. slow down
2. speed up
3. move constantly
4. stop

Q.

The eraser gets smaller and smaller as you use it more and more. Explain the reason

Q.

A meteor starts burning when it enters Earth's atmosphere. Which of the following correctly explains this?

1. Magnetic force produces heat.

2. Electrostatic force produces heat.

3. Gravitational force produces heat.

4. Frictional force produces heat.

Q. When two smooth surfaces slide over each other, the primary cause of friction is .

1. adhesion
2. roughness
3. interlocking
4. deformation