In the middle of a long solenoid there is a coaxial ring of square cross-seciton, made of conducting materaial with respectivity are equal to `h` its inside and outside radii are equal to `a` and `b` respectively. Find the current induced in the ring if the magnetic induction produced by the solenoid varies with time as `B = beta t`, where `beta t`, where `beta` is constant. THe inductance of the ring is to be neglected.

Answer

`(hbeta)/(4 p)(b^(2)-a^(2))`