A thin rod of length L and mass M is bent at the middle point O at an angle 60º, The moment of inertia of the rod about an axis passing through O and perpendicular to heplane of the rod will be

(a) ML^{2}/6

(b) ML^{2}/12

(c) ML^{2}/24

(d) ML^{2}/3

Correct Option (b) ML^{2}/12Explanation :Moment of inertia of a uniform rod about one end = ml

^{2}/3Momento of inertia of the system in which rod is bent

= 2x(M/2)(L/2)

^{2}/3 = ML^{2}/12Note :Here axis is perpendicular to the plane of the rod.