Electric currents make magnetic fields

The magnetic field of an electromagnet is just like the magnetic field of a bar magnet

Magnetic field lines come out of one end of the magnet (its north pole)

The magnetic field lines go back in the other end of the magnet (its south pole)

Hans Christian Oersted was a Danish Scientist (from Denmark)

He thought that there was a connection between electricity and magnetism

One day, in 1820, he was giving a lecture about electric circuits. A compass was lying nearby on a table. When he switched on the circuit he noticed the compass's needle changing...

Oersted discovered that whenever an electric current flows in a wire, it makes a magnetic field around it. ^{This photo shows a modern version of the experiment}

When the switch is closed, the battery makes a current flow in the wire . The compass needle moves around, just like Oersted's experiment

The magnetic field around the wire is quite weak

An electromagnet is a clever idea that works because when you wind the wire into a coil, you concentrate the magnetic field into a smaller space, making it much stronger