Lubricants and Ball Bearings

Q. Oil or grease is applied on moving parts of the machines to reduce friction.

1. True
2. False

Q. Which of the following is not a lubricant?

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

Q.

When two surfaces are coated with a lubricant then they will

1. slide upon each other

2. stick to each other

3. roll upon each other

4. jump on each other

Q.

How does oiling or lubrication help in reducing friction?

Q. We prefer using lubricant like between machine parts operating at high temperatures.

1. liquid
2. solid
3. gaseous
4. grease
5. oil
6. graphite

Q.

Name two lubricants used to reduce friction.

Q.

Friction can be reduced to zero by applying lot of lubricants.

1. rubbing of eraser against paper

2. rubbing of hands gainst each other

Q. Which of the following would you prefer to reduce friction between sliding parts of a machine operating at high temperatures?

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

Q. Ball bearings are used in moving parts of machines to reduce friction in them.

1. False
2. True

Q. By using lubricants, we can reduce ___ between moving parts of machines.

1. smootheness
2. friction
3. movement
4. slipping

Q. Graphite, a solid, is a type of lubricant

1. False
2. True