Class 8 Practice – Level 2 – Set 2 – Friction Solutions

Total questions: 25

Which of the following factors has the greatest effect on friction between two surfaces?

The shape of the object

The normal force exerted by the surfaces

The color of the surface

The temperature of the surface

None

Which of the following is an effect of friction in machines?

It decreases heat production

It causes wear and tear of moving parts

It increases efficiency

It increases the smoothness of surfaces

None

Lubricants are applied to machine parts to:

Reduce efficiency

Decrease friction

Increase friction

Roughen the surface

None

If you rub your hand on a carpet and then on a polished tile, why is there more friction on the carpet?

Carpet has a rough surface

Polished tile has a higher weight

Tile absorbs more force

Carpet is softer

None

A common method to reduce frictional loss in a machine is to:

Use rubber parts

Apply more pressure

Use oil or grease

Increase weight

None

Why is it difficult to slide a heavy object across a carpeted floor compared to a tiled floor?

The carpet is heavier

The carpet increases fluid friction

The carpet creates more resistance due to higher friction

The carpet absorbs weight

None

If a brick is placed flat on the ground and then turned to rest on its narrow side, how does the friction change?

Increases

Decreases

Remains the same

Reduces to zero

None

How do fish reduce fluid friction as they swim?

By having rough scales

By swimming slowly

Through a streamlined body shape

By moving in short bursts

None

Which device directly uses friction to produce heat?

A refrigerator

An electric heater

A matchstick

An air conditioner

None

10.

Which type of friction acts on an object when it is about to start moving?

Sliding friction

Static friction

Rolling friction

Fluid friction

None

11.

Friction helps us walk by:

Reducing weight

Increasing resistance between the ground and our feet

Decreasing speed

Making the ground slippery

None

12.

Grooves in car tires help by:

Reducing tire weight

Increasing friction

Decreasing friction

Absorbing moisture

None

13.

Why do vehicles have wheels instead of being flat-bottomed?

To make them heavier

To reduce rolling friction

To reduce sliding friction

To increase energy use

None

14.

Friction in a machine usually leads to:

Conservation of energy

Increased smoothness

Reduction in efficiency

Decrease in surface roughness

None

15.

Oil is added to a door hinge to:

Increase friction

Prevent rust

Reduce friction

Absorb dust

None

16.

Why is powdered chalk used in sports like gymnastics?

To increase hand moisture

To increase grip by increasing friction

To make hands slippery

To reduce weight

None

17.

When does kinetic friction take over from static friction?

After the object starts moving

Before the object moves

Only for very light objects

Only for very heavy objects

None

18.

Which of these surfaces would likely have the least friction?

Carpeted floor

Sandpaper

Ice

Concrete

None

19.

Which component in a machine helps reduce friction between moving parts?

Chain

Belt

Ball bearings

Gear

None

20.

Increasing the roughness of a surface generally:

Reduces friction

Increases friction

Eliminates friction

Has no effect on friction

None

21.

Which of these actions involves rolling friction?

Kicking a soccer ball

Throwing a ball

Dragging a bag

Lifting a suitcase

None

22.

Which of the following activities makes use of friction?

Sliding on ice

Skiing on snow

Brushing teeth

Floating in water

None

23.

Why do we use textured materials for stairs?

To increase the weight

To reduce friction

To increase grip

To make them look appealing

None

24.

Which situation is NOT an example of friction generating heat?

Rubbing hands

A vehicle’s brake system

Using a metal nail

Striking a match

None

25.

One way to minimize frictional wear in moving parts is by:

Using very rough surfaces

Using softer materials

Adding lubricants

Decreasing part size

None

1 out of 25

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Class 8 Practice – Level 2 – Set 2 – Friction Solutions

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