Question

The moment of inertia of a circular ring about an axis passing through its centre and normal to its plane is I. Then, its moment of inertia about a diameter is

• A. $I$
• B. $\frac{I}{2}$
• C. $\frac{I}{8}$
• D. $\frac{I}{4}$

Answer 1

Answer: (B)

$\frac{I}{2}$

From prependicular axis theroem
We have,
$I_z=I_x+I_y$
Given, $I_Z=I$ and about diameter $I_{=}{I}_y=I^{\prime }$
$\therefore I=I^{\prime }+I^{\prime }$
$\Rightarrow I^{\prime }=I$
$\Rightarrow =\frac{I}{2}$