Electromagnet

An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. The magnetic field disappears when the current ceases.

Electromagnets and permanent magnets

The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be rapidly manipulated over a wide range by controlling the electric current. A disadvantage is that if an electromagnet with a ferromagnetic core is turned on and off again, the core retains some residual magnetization due to hysteresis. This magnetic field can persist indefinitely.

Related Topics:
Permanent magnet - Hysteresis

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In applications where a variable magnetic field is not required, permanent magnets are generally superior. Since an electromagnet requires a constant flow of electricity, it consumes electrical power. Additionally, permanent magnets can be manufactured to produce stronger fields than any electromagnet of similar size.

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