Now that we have studied the differences between DC (direct current) and AC (alternating current) and Thomas Edison and Nikola Tesla it was time to get hands on with our knowledge. We decided to start chronologically with direct current. Homopolar motors are really fun and easy to make. All you need is:
I bought the magnets and batteries at Radio Shack. The wire and tools can be purchased at Home Depot. If I was going to do this experiment all over again I would have purchased thinner wire that was more pliable. The needle nose pliers were very helpful.
To make your homopolar motor use a blunt nail to make an indention to the cathode of your battery. This will help the wire stay in place. Place the magnet to the bottom of the battery. Allow the kids to create shapes with the wire. Just remember one end of the wire needs to be touching the cathode and the other needs to touch the magnet. Once you achieve success its really fun to watch your wire design spin and spin.
Why does it spin? Well the electrical current flows from the positive terminal of the battery to the negative in the magnet. The short answer is the current in the copper wire and the magnetic field kind of work together to create a force that creates the spinning motion.