Question

A rectangle is having base b and height h. The ratio of the moment of inertia when axis is passing through its base to moment of inertia of when axis passing through center of gravity and parallel to base is ___________

(a) 3

(b) 4

(c) 12

(d) 9

I had been asked this question in an international level competition.

This interesting question is from Moments of Inertia of Areas in portion Centres of Gravity, Moments of Inertia, Orthographic Reading and Conversion of Views of Engineering Drawing

Answer 1

The correct option is (b) 4

The explanation is: Moment of inertia of triangle having base b and height h when axis passing through the center of gravity is bh3/12 and moment of inertia when axis passing through base is bh3/3 and ratio is asked it gives 4.