Question

At what conditions the dry friction occurs between the surfaces in contact?

(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

The question was asked in an interview.

I'd like to ask this question from Characteristics of Dry Friction in chapter Friction of Engineering Mechanics

Answer 1

Correct answer is (a) When there is no lubricating fluid

For explanation I would say: 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.