One quarter sector is cut from a uniform circular disc of radius R. The sector has mass M. IT is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is

Options

A. `(1 // 2)Mr^(2)`
B. `(1//4)MR^(2)`
C. `(1//8)MR^(2)`
D. `sqrt(2)MR^(2)`

Answer

A

Explanation

If this sector has mass M then the mass of complete disc would be 4M let the required M.I. = I
`rArr 4I = 1/2 (4M) R^(2) rArr I=1/2 MR^(2)`