August 15, 2016 – With support from Team TREC, campers at Catholic Centre for Immigrants built homopolar motors with three basic supplies: AA battery, copper wire and rare earth magnet. Copper wire is a conductor and AA battery provides the current.
Learning Outcomes: Current, Rotation, Rotations per Minute (RPM), Magnetic field, Rare earth magnet, Wavelength, Particles, and Energy. Campers were surprised and excited to learn that DVD players contain a needle that turns at 5,000-10,000 RPM.
This activity is harder than it looks. The challenge is to experiment with the length of the copper wire. The wire will rotate only if it’s moving counter clockwise. The wire must be close to the magnetic field but not close enough to touch the ground.
The winning homopolar (one-direction) motor created by a camper incorporated four rare earth magnets which strengthened the magnetic field.