An annular circular brass disk of inner radius `'r'` and outer radius `'R'` is rotating about an axis passing through its centre and perpendicular to its plane with a uniform angular velocity `'omega'` in a uniform magnetic filed of induction `'B'` normal to the plane of the disk. The induced emf between the inner and outer edge of the annular disk is

Options

A. `(B omega (r^(2)+R^(2)))/(2)`
B. `(B omega (R^(2)-r^(2)))/(2)`
C. `(B omega (r-R))/(2)`
D. `(B omega (r+R))/(2)`

Answer

B