Question

Ball-bearings are used to reduce the friction by.

• A. Applying lubricants to the balls used
• B. Increasing the area of contact with the use of metallic balls
• C. Reducing the area of contact with the use of metallic balls
• D. None of the above

Answer 1

Answer: (C)

Reducing the area of contact with the use of metallic balls

Ball bearing reduce friction by using smooth balls lubricated with oil or grease that freely roll between a smooth inner and outer surface. The area of contact between inner and outer surface decreases hence friction decreases between them.