A transformer relies on an alternating current in order to work. An electrical transformer converts electromotive force to magnetomotive back to electromotive. In order for an electromotive force to be induced by a magnetic field, the field must be moving.

EMF or electromotive force, i.e.Voltage, is generated when the magnets inside the alternator turn within the wire coil of the alternator.

When current is applied to the primary side, electromotive force is induced in it. It generates magneto-motive force in the core. magneto-motive force generates flux in the core. This flux links with secondary side winding and generates electromotive force in the secondary side according to secondary side turns.

Electromotive force is an old term for voltage.

Electromotive force = electromagnetic force The photon (γ)