Theory of Structures - Engineering

Q1:

If D and d are external and internal diameters of a circular shaft respectively, its polar moment of inertia, is

A

B

C

D

ANS:D -

Polar modulus,Iz = Ix + Iy.
= (πD^4/64)+(πD^4/64),
= πD^4/32.
For the hollow section, you can take D and d.