Question

Friction can be reduced by using

• A. lubricants
• B. streamlined shape
• C. ball bearings
• D. all of them

Answer 1

The correct option is D

all of them

Explanation of correct options:

1. Friction is the force that opposes the motion of one body over another.
2. Friction is due to the interlocking of two surfaces.
3. Friction can be reduced by using lubricants (oil or grease).
4. Friction can also be used by changing the shape of the body i.e making it streamlined.
5. Ball bearing reduce friction by using smooth balls lubricated with oil or grease that freely roll between a smooth inner and outer surface.
6. The area of contact between inner and outer surface decreases hence friction decreases between them.

Hence, the correct answer is Option D