Question

The coefficient of friction of unlubricated surface ranges about _________

(a) 0.1-1.5

(b) 0.1-0.5

(c) 0.1-1.0

(d) 1.5-2.0

I had been asked this question in my homework.

This interesting question is from Mechanism of Lubrication in division Lubricants of Applied Chemistry

Answer 1

The correct option is (a) 0.1-1.5

Easiest explanation: The coefficient of the unlubricated surface is about 0.1 to 1.5. If the lubricant energy is higher, then the energy must be required in large amount to circulate and maintain the viscous lubricant film.