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Electricity and magnetism

Electric generators and motors

Electricity produces magnetismElectricity produces magnetism Electricity and magnetism are so closely linked that one can produce the other. An electric current flowing in a cable produces a magnetic field around the cable. A magnetic field moving near a wire causes electricity to flow along the wire. Electromagnetism is the basis of how both generators and electric motors work.

Ørsted demonstrates his discoveryØrsted demonstrates his discovery


In 1820, the Danish scientist Hans Christian Ørsted (1777–1851) observed that when he passed an electric current through a wire, a magnetic compass needle nearby was slightly deflected. He realised that the electric current had produced magnetism: he had discovered electromagnetism.

How an electric bell worksHow an electric bell works

To work out the direction of motion in an electric motor, use Fleming's left hand rule. Raise your left thumb, point straight ahead with your first finger (index finger) while using your second finger to point at right angles to that. The thuMb indicates Motion; the First finger indicates the direction of the magnetic Field; the seCond finger indicates the direction of the electrical Current.  

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