A coil of N turns, each of area A, is mounted on a light axle so that it can rotate freely in a uniform magnetic field of magnitude B. At t=0 the plane of the coil is perpendicular to the field and the coil is set into steady rotation with a constant angular speed ω about an axis through its centre.
(i) State Faraday’s second law of electromagnetic induction.
(ii) Explain, with reason, how the magnetic flux linked with the coil varies with time during one complete revolution. Hence draw a qualitative graph showing the variation of flux with time.
(iii) Using your result from part (ii), determine the instants (expressed in terms of ω) at which the induced emf in the coil becomes (a) zero and (b) maximum for the first time after t=0.
a. (i)
b. (ii)
c. (iii)