Ways of Reducing Friction

Q. Which of the following methods for reducing fluid friction?

1. Polishing the surface.
2. Decreasing the speed of the object.
3. Reducing the contact area between the surfaces.
4. Increasing the contact area between the surface.

Q.

Rolling friction is ____- than sliding friction.

Q. Question 1 (d)
Fill in the blank:
Sprinkling of powder on the carrom board ________friction.

Q.

Sliding friction is greater than .................. friction.

Q.

Of the following statements choose the correct statement :
A) Grease is used to reduce friction in the bicycle chain.
B) Ball bearings are used to reduce friction in a fan.
C) Oil can be used to increase friction in a car engine.
D) Talc can be used to reduce friction in a carrom board.

1. A, B, D

2. A, C, D

3. B, C, D

4. A, B, C, D

Q.

The birds and fish having___________ shape move through fluids with minimum resistance by frictional force.

Q. When the lubricant is applied between the two surfaces, friction between the two surfaces .

1. increases
2. decreases
3. remains same

Q. If we apply oil on window hinges, the friction will on the hinges will ____.

1. increase
2. decrease
3. become zero
4. remain unchanged

Q. Why is it advantageous to use ball bearings between machine surfaces?

1. Sliding friction is less than rolling friction.
2. Rolling friction is less than sliding friction.
3. Sliding friction is equal to rolling friction.
4. Static friction is more than sliding friction.

Q. Which of the following decreases friction?

1. Spikes on shoes
2. Treading of tyres
3. Powdering a carrom board
4. Rubbing hands with soil

Q.

Which of the following are ways to reduce friction?

1. True

2. False

3. Polishing

4. Using ball bearings

Q. is not a lubricant.

1. Grease
2. Oil
3. Sand
4. Graphite

Q.

You spill a bucket of soapy water on a marble floor accidentally. Which of the following statements is correct?

1. It will be easier to walk after the spilling because force of friction increase

2. It will be difficult to walk after the spilling because force of friction increases

3. It will be difficult to walk after the spilling because force of friction decreases.

4. It will be easier to walk after the spilling

Q.

Rolling friction is greater than sliding friction.

1. True
2. False

Q.

In factories, friction between moving parts of heavy machineries is reduced by ___________.

1. using sand

2. using lubricants

3. cooling machine parts

4. heating machine parts

Q.

Why is talcum powder sprinkled on the carrom board?

1. To make the board durable

2. To reduce friction

3. To maintain friction

4. To increase friction

Q.

Friction can be reduced to zero by applying lots of lubricants between surfaces.

1. rubbing of hands gainst each other

2. rubbing of eraser against paper