The objective of this experiment is to further demonstrate the relationship between electricity and magnetism. We will show how to use electricity to magnetize metal.
Several feet of insulated wire
A nail (or a bolt)
Small metal objects (e.g., thumbtacks, paper clips, etc.)
How to Build It
Begin at one end of the nail and wrap the wire in small loops around the nail. The loops should be tight around the nail.
Attach the ends of the wire to the terminals of the battery. Touch the end of the nail to one of the metal objects. The object should stick to the nail. See how many objects you can pick up.
Now try wrapping more wire back over the loops previously made. The wire should still wrap around the nail the same way as before. Attach it the battery again and see how many objects you can pick up now.
Now let us determine which side of the electromagnet is north and which is south. Bring the north side of the permanent magnet (PM) to one end of the nail. Does the electromagnet repel or attract the PM? If the electromagnet repels the permanent magnet, then it is the north side of the electromagnet; if the electromagnet attracts the PM, then it is the south side. Just as opposite charges attract, so do opposite poles.
If your electromagnet does not seem to be working, try the following:
This experiment is contained in nearly every book which deals with electricity.