Question

When a wire loop is rotated in a magnetic field, the direction of induced e.m.f. changes once in each
(a) $\frac{1}{4}$ revolution
(b) $\frac{1}{2}$ revolution
(c) 1 revolution
(d) 2 revolution

Answer 1

b).1/2 revolution ..WHEN A WIRE LOOP IS ROTATED IN A MAG. FIELD,THE DIRECTION OF E.M.F. CHANGES EVERY 1/2 A SEC.