An electro-magnet is a device consisting of a coil of insulated wire i.e. a solenoid into which is introduced a core of magnetic material. The core which is usually made of soft iron becomes temporarily magnetized when a current flow through the solenoid. As soon as the current is stopped the device looses most of its magnetic effect.

A coil with a given amount of ampere-turns is able to produce greater amount of magnetic flux when soft iron core is inserted into the coil because of its high permeability as compared to that of air, therefore, very powerful magnets, known as electro-magnets may be made by placing a coil around a soft iron core. The strength of electro-magnets depends upon the permeability of the core, number of turns of coil and current flowing through the coil. The strength of electron-magnet with a given number of turns on the coil may be varied by varying the strength of current flowing through the coil.


A simple horse shoe magnet is shown in. When the magnet is bent in the form of a horse shoe, the north and south poles are brought adjacent to another.

Electromagnets are widely used to produce magnetic field in electric generators, motors and instruments.

Electro-magnets are also used as lifting magnets to move scrap iron.
Other applications of electro-magnets are in relays, motor controllers, circuit breakers, electrically operated valves and motor brakes.

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