An A.C. generator is a device that uses energy from the kinetic store to produce electricity in the form of an alternating current.

1. Coil of wire
2. Magnetic field

When the coil is rotated, it cuts through the magnetic field lines which induces a current in the coil.

The slip rings maintain the connection between the rotating coil and the external circuit, allowing the current to flow out of the generator.

E.m.f. (Electromotive Force) is the energy provided by the generator per coulomb of charge that passes through it.

Increasing the speed of rotation increases the rate at which the coil cuts through the magnetic field lines, increasing the e.m.f. output.

Using a stronger magnet increases the magnetic field strength, which increases the e.m.f. output.

Increasing the number of turns on the coil increases the total length of wire cutting through the magnetic field lines, increasing the e.m.f. output.