Two rings of radius R and nR made of same material have the ratio of moment of inertia about an axis passing through center is `1:8`. The value of n is

Options

A. 2
B. `2sqrt(2)`
C. 4
D. `1/2`

Answer

A

Explanation

As radius of round ring is n times, length and hence mass of wire is also n times.
`I_(1)/I_(2) =(Mr^(2))/(nM(nR)^(2)) =1/n^(3) =1/8 rArr n=2`