A current makes a magnet: the electromagnet

0:00Can an electric current make a magnet? Let us build one and see.

0:05On its own, an iron nail is not a magnet. It does not pull these steel clips.

0:12Wrap a long wire round the nail many times. This is called a coil.

0:17Join the two ends of the wire to a battery, with a switch in the circuit.

0:22Close the switch. Now an electric current flows through the coil.

0:28Every electric current makes a magnetic field around it. The coil makes a field like a bar magnet.

0:34The field makes the iron nail into a strong magnet, with a north pole and a south pole.

0:41Now it pulls the steel clips, just like any magnet.

0:45A magnet made by an electric current is called an electromagnet.

0:50Open the switch. The current stops, the field is gone, and the nail stops being a magnet.

0:57So an electromagnet can be switched on and off. A bar magnet cannot.

1:03More turns of wire, or a bigger current, make the electromagnet stronger.

1:09So an electric current in a coil round an iron nail makes a magnet. That is an electromagnet.