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An electromagnet is a coil with a ferromagnetic core inserted into it.

The magnetic field of a current-carrying coil is of particular practical interest. If a coil with current is suspended on thin and flexible wires, it will align itself just like a compass needle: one end will point north, and the other end will point south. Thus, the coil, like a magnetic needle, has two magnetic poles, a north pole and a south pole. Knowing this, the direction of the current can be determined using the right-hand rule (corkscrew rule).

To strengthen the magnetic field of a current-carrying coil, a ferromagnetic core is placed inside the coil. A coil with a core inside is called an electromagnet.

The magnetic field can also be strengthened by:

  • Increasing the current in the coil enhances its magnetic effect.
  • Increasing the number of turns in the coil enhances its magnetic effect.

Structure of an electromagnet

The simplest electromagnet is a conductor wound around a cylindrical core, known as a solenoid.


Electromagnets come in various shapes. The core of an electromagnet is often given a horseshoe shape, as in this case, the magnetic effect of the electromagnet is significantly enhanced.

Properties of electromagnets

  • Electromagnets rapidly demagnetize when the current is switched off.
  • The strength of the magnetic field can be regulated by adjusting the current, thereby increasing or decreasing the magnetic field.

These properties allow for the wide use of electromagnets, for example, in lifting loads due to rapid magnetization and demagnetization, or in electromagnetic relays that control an electric circuit by attracting an armature that closes the contacts, and more.

Electromagnets are used wherever a magnetic field that can be easily and rapidly changed is needed. They can be found in automobiles, phones, computers, televisions, airplanes, and ships.