devarshi-dt-logo

Question:

The phase difference between the flux linked with a coil rotating in a uniform magnetic field and induced emf produced in it is

π

π/2

π/3

−π/6

Solution:

The flux linked with the coil ϕ=B.A=BAcoswt where w is the angular speed of rotation
Induced emf E=−dϕdt=−(BAw)(−sinwt)=BAwsinwt⟹E=BAwcos(wt−π2)
Hence phase difference between flux linked with the coil and induced emf is π/2.