Question

Which of the following conditions is TRUE for the shafts connected in series to each other?

• A. θ1 = θ2
• B. T = T1 + T2
• C. θ = θ1 + θ2
• D. θ1 = θ2 and T = T1 + T2

Answer 1

Answer:

C. θ = θ1 + θ2

When two shafts are connected in series, both carry the same torque and the total angle of twist at the resisting end is the sum of individual angles of twist. Hence, option 3 is correct. The equation for angle of twist is $\theta = \theta_{1} + \theta_{2} = \frac{TL_{1}}{G_{1}J_{1}} + \frac {TL_{2}}{G_{2}J_{2}}$ where T is the torque, L is the length, G is the modulus of rigidity, and J is the polar moment of inertia.