A metal rod of resistance `20 Omega` is fixed along a diameter of a conducting ring of radius `0.1 m` and lies on `x-y` plane. There is a magnetic field `vec(B) = (50 T)vec(k)`. The ring rotates with an angular velocity `omega = 20rad s^(-1)` about its axis. An external resistance of `10 Omega` is connected across the center of the ring and rim. The current external resistance is

Explanation

`e = (1)/(2)Bl^(2) omega = (1)/(2) xx 50 xx 0.1 xx 0.1 xx 20` ,
`:. e = 5V` Hence the current through the external resistance is `i = (e)/(R ) :. i = (5)/(15) = (1)/(3)A`