question_answer

The moment of inertia of a uniform circular disc of radius 'R' and mass 'M' about an axis passing from the edge of the disc and normal to the disc is

A) \[M{{R}^{2}}\]

B) \[\frac{1}{2}M{{R}^{2}}\]

C) \[\frac{3}{2}M{{R}^{2}}\]

D) \[\frac{3}{2}M{{R}^{2}}\]

Correct Answer: C

Solution :

[c] M.I. of a uniform circular disc of radius 'R' and     mass 'M' about an axis passing through C.M and normal to the disc is \[{{I}_{C.M.}}=\frac{1}{2}M{{R}^{2}}\] From parallel axis theorem \[{{I}_{T}}={{I}_{C.M.}}+M{{R}^{2}}=\frac{1}{2}M{{R}^{2}}+M{{R}^{2}}=\frac{3}{2}M{{R}^{2}}\]