Alternating-Current Generator

rotate

Michael Faraday invented the electric generator to convert mechanical energy into electrical energy. It consists of a number of wire loops rotating freely in a magnetic field. When the velocity of the loop is perpendicular to the magnetic field, the current

I

produced by the induced EMF (electromotive force, the potential difference given to charges, commonly by a battery) is greatest, reaching a maximum value

I

max

. For an alternating current generator—also known as an alternator—the electric current inverts its direction each half-spin, as shown by the orange arrow.

Increasing the iron core or the number of loops increases the induced EMF and then the current.