Device in which an electric Current, passing through a wire coil wrapped around a soft iron core, produces a Magnetic Field. The magnetic-field strength produced depends on the number of turns of the
coil of wire, the size of the current, and the magnetic permeability of the
core. Electromagnets made with superconducting coils (see Superconductivity) offer no Resistance to an electric current and can produce a strong magnetic field.
Electromagnets lose their magnetism when the current is discontinued.