17.A rod of length l and radius r is joined to a rod of length l/2 and radius r/2 of same material. The free end of small rod is

A rod of length l and radius r is joined to a rod of length l/2 and radius r/2 of same material. The free end of small rod is fixed to a rigid base and the free end of larger rod is given a twist of θ°, the twist angle at the joint will be

(a)  θ/4                                                  (b)  θ/2

(c)  5θ/6                                                 (d)  8θ/9

Answer-d

(8)