Question

The moment of inertia of an annular disc of mass $M$, outer and inner radii $R$ and $r$, about its diameter is

• A. $M(R^2+r^2)/2$
• B. $M{R}^2$
• C. $M{r}^2$
• D. $M(R^2+r^2)/4$

Answer 1

Answer: (D)

The moment of inertia of an annular disc about its diameter
$=\frac{M\left(R^2+r^2\right)}{4}$
where, $R$ is the outer radius of disc, $r$ is the inner radius of disc and $M$ is the mass of disc.