A thin rod of length I and mass m is bent at mid-point O at angle of `60^(@)` . The moment of inertia of the rod about an axis passing through O and perpendicular to the plane of the rod will be

Options

A. `(ml^(2))/(3)`
B. `(ml^2)/(6)`
C. `(ml^2)/(8)`
D. `(ml^2)/(12)`

Answer

D

Explanation

Moment of inertia of a uniform rod about one end = `(ml^3)/(3)`
Moment of inertia of the system = `2 xx ((m)/(2)) ((l//2)^(2))/(3) = (ml^2)/(12)`