Build a Simple Electromagnet
An electromagnet is the magnet in which the magnetic field is produced by an electric current. Electromagnet consists of a coil wrapped with a wire. The current through the wire turns the coil into a magnet.
30 cm copper wire
A long nail
Battery 4.5 Volt
Wrap the wire several times around the nail. Scrape the ends of the wire to remove the insulation. Connect the ends of the wire to the battery poles and your magnet is ready. Caution: use an electrical tape to cover the connection between the wire and the battery. Approach the nail to the paperclips and watch it pull them!!
When the ends of the wire are connected to the battery poles electric current flows in the wire. Electric current produces magnetic field around it, so the nail (located within this field) magnetizes and pulls the paperclips. Electromagnets are temporary magnets that lose their magnetism when current stops.