Question

What is the range of coefficient of friction for solid lubricants?

(a) 0.005-0.01

(b) 0.001-0.01

(c) 0.0001-0.001

(d) 0.0005-0.001

This question was addressed to me during an interview for a job.

The query is from Classification of Lubricants in chapter Lubricants of Applied Chemistry

Answer 1

Right option is (a) 0.005-0.01

For explanation I would say: The range of the coefficient of friction for solid lubricants is very less that of 0.005-0.01. This must be low for effective lubrication because the lubricant is mainly used to control the friction between the machine parts.