Question

The moment of inertia of a solid cylinder about its natural axis is I. if its moment of inertia about an axis $\bot$ to natural axis of cylinder and passing through, one end of cylinder is 191/6 then the ratio of radius of cylinder and its length is

• A. 1 : 2
• B. 1 : 3
• C. 1 : 4
• D. 2 : 3

Answer 1

Answer: (A)

$I = \frac{MR^2}{2}$
$I_1 = \frac{19I}{6} = \frac{ML^2}{3} + \frac{MR^2}{4}$
$\Rightarrow $ $\frac{19}{6} \left( \frac{MR^2}{2} \right) = \frac{ML^2}{3} + \frac{MR^2}{4}$
$\Rightarrow $ $\frac{R}{L} = \frac{1}{2}$