question_answer

Seven identical circular planar disks, each of mass M and radius R are welded symmetrically as shown. The moment of inertia of the arrangement about the axis normal to the plane and passing through the point P is:

[JEE Main Online 08-04-2018]

A)   \[\frac{\text{73}}{\text{2}}\text{M}{{\text{R}}^{\text{2}}}\]  

B)        \[\frac{\text{181}}{\text{2}}\text{M}{{\text{R}}^{\text{2}}}\]

C)   \[\frac{\text{19}}{\text{2}}\text{M}{{\text{R}}^{\text{2}}}\]  

D)        \[\frac{\text{55}}{\text{2}}\text{M}{{\text{R}}^{\text{2}}}\]

Correct Answer: B

Solution :

[b]