Question

The moment of inertia of a hollow cylinder of radius $R$ and mass $M$ about an axis passing through the outer circumference along the height of the hollow cylinder is

• A. $M{R}^2$
• B. $\frac{M{R}^2}{2}$
• C. $4M{R}^2$
• D. $2M{R}^2$

Answer 1

The correct option is D $2M{R}^2$


Let $I_{com}$ be the moment of inertia of the hollow cylinder about the axis passing through its C.O.M.

Applying parallel axis theorem,
$I=I_{com}+M{d}^2$ $[\because$ here $d=R]$
$=M{R}^2+M{R}^2$
$[\because I_{com}=M{R}^2$ for hollow cylinder$]$
$\Rightarrow I=2M{R}^2$