question_answer

The moment of inertia of a circular disc of radius 2m and mass 1 kg about an axis passing through the centre of mass but perpendicular to the plane of the disc is 2 kg m2. Its moment of inertia about an axis parallel to this axis but passing through the edge of the disc is (see the given figure).

A) \[8\text{ }kg\text{ }{{m}^{2}}\]       

B)  \[4kg\text{ }{{m}^{2}}\]

C) \[10\text{ }kg\text{ }{{m}^{2}}\]      

D)  \[6kg\text{ }{{m}^{2}}\]

Correct Answer: D

Solution :

According to parallel axis theorem    \[{{I}_{XY}}={{I}_{XY}}+M{{R}^{2}}\] \[=2+(1){{(2)}^{2}}\] \[=6\,kg-{{m}^{2}}\]