Question

Let $I_A$ and $I_B$ be moments of inertia of a body about two axes $A$ and $B$ respectively. The axis $A$ passes through the centre of mass of the body but $B$ does not

• A. $I_A$< $I_B$
• B. If $I_A$< $I_B$, the axes are parallel
• C. If the axes are parallel, $I_A$< $I_B$
• D. If the axes are not parallel, then $I_A$ $\ge$ $I_B$

Answer 1

Answer: (C)

If the axes are parallel, $I_A$< $I_B$

The moment of inertia is always less for an axis passing through the center of mass than any other parallel axis. We cannot say anything of the moment of inertia about a non parallel axis. Thus C is correct.