A conducting ring of radius `'r'` is rolling without slipping with a constant angular velocity `omega` (figure). If the magnetic field strengh is `B` and is directed into the page the emf induced across `PQ` is

Options

A. `B omega r^(2)`
B. `(B omega r^(2))/(2)`
C. `4 B omega r^(2)`
D. `(pi^(2) r^(2)B omega)/(8)`

Answer

A

Explanation

`|vec(E)| = (Bl^(2))/(2) omega," "l = sqrt(2) r`