Question

One solid sphere A and another hollow sphere $B$ are of same mass and same outer radii. Their moment of inertia about their diameters are respectively $I_A$ and $I_B$ such that:
where $d_A$ and $d_B$ are their densities.

• A. $I_A=I_B$
• B. $I_A>I_B$
• C. $I_A<I_B$
• D. $I_A/I_B=d_A/d_B$

Answer 1

The correct option is C $I_A<I_B$

Given; mass and radius of both the spheres are same.

Now as moment of inertia of solid sphere, $I_A=\frac{2}{5}M{R}^2$

Moment of inertia of hollow sphere, $I_B=\frac{2}{3}M{R}^2$

$⟹I_A<I_B$