Electricity and Magnetism

For a long time people thought that electricity and magnetism were two completely separate
phenomena. In 1820, the Danish physicist Hans Christian Oersted discovered that electric
currents create magnetic field. When current is sent through a coil of wire, the coil becomes a
magnet with its two magnetic poles and it functions as a magnet. This type of magnets are now
called electromagnets. Then in 1831, the English physicist Michael Faraday discovered that
when a magnet was inserted through a coil of wire it created current in the wire. A change in the
magnetic flux through a coil of wire could induce current in the wire. This phenomenon is now
called Faraday’s law. These two discoveries showed a very close relationship between
electricity and magnetism. In fact, it is believed that the source of both electricity and magnetism
is the electric charge. Electricity and magnetism have been unified as a single phenomenon and
it is well described by the electromagnetic theory.