Question

A rod of mass m length l can rotate without friction about the centre of a vertical ring . There is a unifrom mafgnetic filed B into the plane of the ring . A variable emf `epsilon` is applied between the centre and the rotating end of the rod . Caulcate the current which keeps the rod rotating with unifrom speed `omega` and the emf requried to maintain the required current

Answer 1

Correct Answer - `i=(mg cos omega t)/(Bl), epsi=(1)/(2) Bomegal^(2)+(mg R cos omegat)/(Bl)`