Question

External diameter of the clutch facing is limited to 120 mm and the inner diameter may be assumed to be 0.3 times the external diameter. Assume uniform wear theory. What is the effective mean radius?

(a) 68

(b) 58

(c) 98

(d) 78

I got this question during a job interview.

Origin of the question is Transmission System in section Chassis & Transmission System of Automobile Engineering

Answer 1

The correct answer is (d) 78

Easy explanation: External diameter = 120 mm. Given Internal diameter = 0.3*external diameter = 0.3 * 120 = 36 mm. Effective mean diameter = (120 + 36) / 2  = 78 mm ⇒ Effective mean radius = 39 mm.