Calculate the M.I. of a thin uniforn ring about an axis tangent to the ring and in a plane of the ring, if its M.I. about an axis passing through the centre and perpendicular to plane is `4kg m^(2)`.

Options

A. `12kg m^(2)`
B. `3kg m^(2)`
C. `6kg m^(2)`
D. `9 kg m^(2)`

Answer

C

Explanation

`(I_(T))/(I_(e ))=((3)/(2)MR^(2))/(MR^(2))=(3)/(2)`
`I_(T)=(3)/(2)I_(c )=(3)/(2)xx4=6`