Today we tried making electromagnets. It was load of fun! We used a D cell battery, a 3 1/2" nail (not galvanized) and some 20 gauge solid core wire. All you have to do is strip about 1" off of each end of the wire and coil it around the nail. After that you tape one end of the stripped wire to one end of the battery and touch the other stripped end of the wire to the other end of the battery. Voila! An electromagnet. Here's what it looked like.
The lesson is that electrical current (electrons flowing through the wire) creates a magnetic field perpendicular to the direction of their flow. The bigger the battery, the stronger the magnet. The more coils, the stronger the magnet. Try it with a non-magnetic metal like aluminum foil. It won't work.
Do NOT use a car battery and do NOT use electricity off of a wall outlet. You could be seriously injured. You'll also find that if you handle the stripped wire directly as you touch it to the battery it gets very hot. We found that handling just the insulated part was cool to the touch.
You can do fun things with them afterwards like trying to see how fast you can pick up metal objects. Like this.
For more homeschooling fun, visit this week's Carnival of Homeschooling.