Two identical coils, each of area 0.020m2, are mounted on the same shaft so that they rotate together in a uniform magnetic field of 0.50T. The coils are connected in series. If the shaft rotates at 1500rev min−1, what is the smallest integer number of turns that each coil must have for the series combination to supply 220V rms?
(a) 70 turns
(b) 50 turns
(c) 100 turns
(d) 200 turns