An AC generator, also known as an alternator, is a device that converts mechanical energy into electrical energy in the form of alternating current (AC). It works on the principle of electromagnetic induction, where a conductor, usually a coil of wire, rotates within a magnetic field, generating electricity. AC generators are commonly used in power plants, vehicles, and various industrial applications. They provide a reliable source of electricity for homes and businesses, as AC can be easily transformed to different voltages for efficient transmission over long distances.