Electromagnets

An electromagnet, also known as an electromagnetic actuator, is a type of magnet in which the magnetic field is produced by an electric current. Unlike permanent magnets, whose magnetic field is constant, the magnetic field of an electromagnet can be activated or deactivated by controlling the flow of electric current.

The electromagnet or electromagnetic actuator consists of a winding and a pole piece of soft ferromagnetic material called the magnetic core, which channels the magnetic field lines.

Wire coil

The electromagnet or electromagnetic actuator consists of a coil of conductive wire, usually copper, wound in a spiral to form a coil. When an electric current passes through this coil, it creates a magnetic field.

Soft iron core

The soft iron core is often placed inside the coil to strengthen the magnetic field. Soft iron is used because of its ability to become magnetic easily and to lose its magnetism quickly when the electric current is switched off.

Passage of an electric current

When an electric current passes through the wire coil of the electromagnet, it generates a magnetic field around the coil according to Biot-Savart's law.

Amplification of the magnetic field

The electromagnet's soft iron core amplifies the magnetic field by magnetising itself.

Activation and deactivation

The electromagnet's magnetic field can be activated or deactivated by switching on or off the electric current flowing through the coil. When the current is switched off, the magnetic field disappears.