The principal reason voltage is induced in the loops of a generator coil is that the

a. loops are rotating, changing the amount of magnetic field within the loops.

b. size of the loops is changing.

c. magnet's strength is changing.

d. magnet is rotating. E. all of the above

The principal reason voltage is induced in the loops of a generator coil is that the loops are rotating, changing the amount of magnetic field within the loops. The answer is letter A. For example, in a circuit, the electrons in the bulb will not move without the potential difference or voltage. When there is voltage, electric current occurs because there is a driving force for the electrons in the wire to move.