A metallic rod of 1 m length is rotated with a frequency of 100 rev/s, with one end hinged at the centre and the other end at the circumference of a circular metallic ring of radius 1 m, about an axis passing through the centre and perpendicular to the plane of the ring (see fig). A constant and uniform magnetic field of 1 T parallel to the axis is present everywhere. What is the emf between the centre and the metallic ring?

Question

$\begin{array}{1 1} 157V \\ 314V \\ 471V \\ 78.5\;V\end{array}$