Simple Motors

Simple Motor

This experiment will show students how to build a simple electric motor. This is best for students twelve and older as it requires some delicate work.

Materials

For each motor you'll need one C battery, a small but strong magnet, about three feet of magnet wire (buy it at Radio Shack, online, or any hardware store), two safety pins, a rubber band, sticky putty, and a small piece of sandpaper. Magnet wire has a plastic coating. 

EXPLANATION:

When electricity is passed through a wire coil (as you are doing when you connect the coil to the battery), you create an electromagnetic field, which pushes the coil away from the magnet.1,2 When you give the coil a spin, since one side of the wire is insulated, you break the circuit briefly, so the coil continues to rotate using its momentum. When the circuit is complete again, the magnetic field once again repels the coil, so it keeps spinning. The motor can continue to spin until the battery is dead!

Wrap the coil around a circular object like a marker.

Slide the wire off the pen to create a coil. Diameter is ~1 cm.

The fully assembled electric motor.