Question

At what conditions does the Coulomb friction occur between the surfaces in contact of journal bearing?

(a) When there is no lubricating fluid

(b) When there is no friction fluid

(c) When there is no adhesive fluid

(d) When there is no cohesive fluid

This question was addressed to me by my college director while I was bunking the class.

I'd like to ask this question from Frictional Forces on Journal Bearings in chapter Friction of Engineering Mechanics

Answer 1

The correct answer is (a) When there is no lubricating fluid

Explanation: When there is no lubricating fluid present between the surfaces in contact, the dry friction occurs. Thus as the name suggests dry friction. When there is no liquid present over there the surfaces are going to be said dry only. Thus the term dry friction.