Electromagnetic Motor-Sick Science!

Design 1

1. Use the pliers to bend a copper wire into the shape you see in the picture on the right. The top of the wire should resemble a heart shape. The bottom of the wire, where the two ends meet, should make a slightly open circle.
2. Place both of the neodymium magnets onto the negative side of the AA battery.
3. Slide the open circle end of the wire around the battery and balance the heart shaped end of the wire on the positive end of the battery.
4. Make sure the bottom of the wire (the slightly open circle) is touching the magnets and... voila! You've got a spinning motor.

Design 2

1. Use the watch battery to power one of the LED lights. To do this, slide the watch battery between the wires of the LED light. Press one of the LED wires against the positive side of the battery and the other wire against the negative side of the battery.
2. Tape down the LED wire that is touching the negative side of the battery.
3. Slide one wire from the other LED light underneath the piece of tape. The LED light's second wire should be against the positive side of the battery.
4. Carefully place the neodymium magnet against the positive end of the watch battery. At this point, both LED lights should be lit up.
5. Place the head of the screw in the center of the magnet opposite the LED lights.
6. Place the tip of the screw in the center of the negative end of the C battery.
7. Use the copper wire to touch the positive end of the C battery and the neodymium magnet and the motor will begin spinning.

You don't need the LED lights to perform this experiment, but it looks incredible!

How does it work?

What you have created is called an electromagnetic (scientifically, homopolar) motor. An electromagnetic motor works through a magnetic field along the axis of rotation and an electric current that, at some point, is not parallel to the magnetic field. Sound complicated? It is! So let's try to make it a bit simpler.

In Electromagnetic Motor Design 1, you have an electric current flowing throughout the circuit. The current, at some point while traveling through the system, is not parallel to the magnetic field of the neodymium magnet. At the point where the forces of the current and magnetic field are not parallel, there is a force called a Lorentz force. The Lorentz force occurs in electromagnetic fields, such as the one we've created with this system. It is the Lorentz force that causes the copper wire to rotate.

The same principles are applied to Electromagnetic Motor Design 2. However, in Design 2, there are no copper wires to rotate. But that's ok, we don't need them because the screw and the magnet spin! When you connect the positive end of the battery to the neodymium magnet (attached to the negative end of the battery by way of the screw) you create the necessary electromagnetic field to produce the Lorentz force. But since there is such a small amount of friction between the screw and battery, the Lorentz force directly affects the magnet. The magnet and screw continue to spin long after you've removed the wire that closes the system because of the small amount of friction.