Question

The moment of inertia of an thin circular disc about an axis passing through its center and perpendicualr to its plane, is l. Then, the moment of intertia of the disc about an axis parallel to its diameter and touching the edge of the rim is
A. l
B. 2l
C. 3/2l
D. `5/2`l

Answer 1

d) Moment of inertial of a circular disc about an axis passing throgh center of gravity and perpendicular to its plane
`I = 1/2MR^(2)`……………..(i)
From Eq. (i) , `MR^(2) = 2l`
Then, moment of inertia of disc about tangent in a plane
`5/4MR^(2) = 5/4(2l)= 5/2l`