Choose the correct option:
A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced cum changes once in each:
(a) two revolutions
(b) one revolution
(c) half revolution
(d) one-fourth revolution
When a rectangular coil of copper wires is rotated in a magnetic field, the direction of the induced cum changes once in each half revolution. Thus, option (c) is correct.