Calculate the moment of inertia of a ring about a tangent to the circle of the ring normal to its plane.

Explanation

Moment of inertia of the ring through `CM` is
`I=MR^(2)`
Using parallel axis theorem
`I=I_(cm)+Md^(2)`
`d=R` so `I=MR^(2)+MR^(2)=2MR^(2)`

Hint : Use parallel axis theorem.