question_answer

 A metallic rod of length R is rotated with an angular frequency to 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)                 \[2B{{R}^{2}}\omega \]                

D) \[B{{R}^{2}}\omega \]