Two conducting rings of radii r and 2r move in opposite directions with velocities 2v and v respectively on a conducting surface s. there is a uniform magneitc field of magnitude B perpendicular to the plane rings. The potential difference between the highest points of the two rings is

Explanation

Replace the induced emfs in the rings by cells of emfs
`e_(1)= B2r(2v) = 4Brv`
`e_(2)= B(4r)v=4Brv`

The equivalent circuit is Hence the potential difference between the highest points of the two rings is `V_(2)-V_(1) = e_(1)+e_(2)=8Brv`