A circular coil with N turns and radius = 0.05 m is rotating in a uniform magnetic field of 0.5 T. At t = 0 s, the normal to the coil is
perpendicular to the magnetic field. At t = 0.2 s, the normal is parallel with the field because the coil has made one-quarter of a revolution. An average emf of magnitude 0.49 V is induced in the coil. How many turns does the coil have?