SHAFT IN PARALLEL:

SHAFT IN PARALLEL: The shaft are in parallel when the driving torque is applied at

the junction of shafts and resisting torque is at other ends of the shafts. Here, angle of twist is same for each shaft, but applied torque is divided between the 2 shaft.

i.e.                                                θ₁ =  θ ₂    and T = T₁  + T₂

if shaft are made of same material than G₁  = G₂

Such situation (θ₁ = θ₂ and T = T₁ + T₂) also arises when shaft ends are fixed and are subjected to a torque at common junction. As shown in figure given below