In a simple electric generator, a conducting loop of wire is placed in a magnetic field. The loop of wire is then rotated. Why is it necessary for the wire to be rotated?

Question

A.
Its motion through the magnetic field creates a current in the wire.
B.
Its motion through the air transforms heat into magnetism.
C.
Its motion removes the magnetic field by using up the magnetic energy.
D.
Its motion when it moves upward changes gravity into magnetism.

Answer 1

The correct answer is:

A. Its motion through the magnetic field creates a current in the wire.

When the conducting loop of wire is rotated in a magnetic field, the motion of the wire relative to the magnetic field lines induces an electromotive force (EMF) in the wire according to Faraday's law of electromagnetic induction. This induced EMF drives a current through the wire if the circuit is closed. Therefore, the rotation is necessary to generate electricity by creating a difference in magnetic flux through the loop over time.