Have fun building your own electromagnetic at home with the help of Science Bob and a few common household items. While a permanent magnet, like those we place on refrigerator doors, never loses its magnetic quality, an electromagnet is a temporary magnet that only works when electricity flows through its wires. You can also watch a video of the experiment.

Materials
1. A 3" iron nail
2. About 3 feet of thin-coated copper wire
3. A new "D" size battery
4. Several paper clips
5. Tape

Directions
1. Leaving about eight inches of wire loose at one end, wrap the wire around the nail. Try not to overlap the wire.
2. Leave eight inches loose at the other end. Cut the wire if needed.
3. Remove one inch of plastic coating from each end of the wire.
4. Attach one wire to one end of a battery and the other wire to the other end of the battery. Caution: do not touch the wires now, as they can become very hot.
5. Now that you have an electromagnet, test it by holding the pointed end of the nail over a few paper clips to pick them up. Try other small magnetic objects.
6. Remove the wire from the battery when you conclude your experiment.

Questions to Consider
1. Does the number of times you wrap the wire around the nail affect the strength of the nail?
2. Does the thickness or length of the nail affect the electromagnet's strength?
3. Does the thickness of the wire affect the power of the electromagnet?

Source: sciencebob.com