JEE Main 2022 — Rotational Motion Question with Solution

(A) Moment of inertia of solid sphere of radius R about a tangent $$=\frac{2}{5}M{R}^2+M{R}^2=\frac{7}{5}M{R}^2$$

$$\Rightarrow$$ A $$-$$ (II)

(B) Moment of inertia of hollow sphere of radius R about a tangent $$=\frac{2}{3}M{R}^2+M{R}^2=\frac{5}{3}M{R}^2$$

$$\Rightarrow$$ B $$-$$ (I)

(C) Moment of inertia of circular ring of radius (R) about its diameter = $$\frac{\left(M{R}^2\right)}{2}$$

$$\Rightarrow$$ C $$-$$ (IV)

(D) Moment of inertia of circular disc of radius (R) about any diameter

$$=\frac{M{R}^2/2}{2}=\frac{M{R}^2}{4}$$

$$\Rightarrow$$ D $$-$$ (III)