Electromagnets
Electromagnets are another kind of magnet. They only work when electricity is running through them. Often, these magnets work by using a coil of wire that makes a magnetic field when there is a current in it. In addition to this coil of wire, a large piece of metal, usually iron, is placed inside the coil to increase the magnetic field made. Though most large electromagnets employ many solenoids to lift heavy objects, smaller solenoids are used in everyday electronics. For example, they are used to change voltage in a transformer. Electromagnets can also be used to make electricity. Movement of a magnet back and forth in front of the electromagnet will make an electric current.