diameter to produce an angular twist at the free end

Question

A torque T is applied at the free end of a stepped rod of circular cross-sections as shown in the figure. The shear modulus of the material of the rod is G. The expression for diameter to produce an angular twist θ at the free end is

 

(a) (b)

(c) (d)

Answer 1

Given a stepped bar in which torque is applied at itsfree end