question_answer

A metallic rod of length R is rotated with an angular frequency co with one end hinged at the centre and the other end at the circumference of a circular metallic ring of radius R, about an axis passing through the centre and perpendicular to the plane of the ring. There is a magnetic field B, perpendicular to the plane of the ring. The emf induced between the centre and the metallic ring is

A)  \[B\,\,\sin \,\,\omega t\]

B)  \[\frac{B{{R}^{2}}\omega }{2}\]

C)  \[2\,B{{R}^{2}}\omega \]

D)  \[B{{R}^{2}}\omega \]