Question

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
A. `1/4A`
B. `1/2A`
C. `1/3A`
D. zero

Answer 1

Correct Answer - C
`(BomegaR^(2))/2=10 i/2+10 i rArr ((50)(20)(0.1)^(2))/2=(30i)/2 i=1/3A`