Question

The moment of inertia of a circular wire of mass M and radius R about its diameter is​

Answer 1

Moment of inertia of a circular wire about its axis is MR2.

For finding moment of inertia around its diameter, you have to use perpendicular axis theorem.

Considering its two diameters that are perpendicular to the axis

I + I = MR2

I = (MR2)/2