A conducting ring of mass `m = pi kg` and radius `R = (1)/(2)m` is kept on a flat horizontal surface (xy plane). A uniform magnetic field is switched on in the region which changes with time (t) as `vec(B) = (2hatj +t^(2) hatk)T`. Resistance of the ring is `r = pi Omega` and `g = 10 ms^(-2)`.
(a) Calculate the induced electric field at the circumference of the ring at the instant it begins to topple.
(b) Calculate the heat generated in the ring till the instant it starts to topple.

Answer

(a) `10 V//m` (b) `(2pi)/(3)kJ`