The Magical Moving Copper Wire Experiment is a homopolar motor science project that will fascinate your 12-year old. The project requires some patience – the motors take some time to create. Boys will also like racing their homopolar motor batteries on tinfoil which takes a few seconds to set up.   

Supplies Needed

For the Magical Moving Copper Wires

  • ¼” Neodymium disc magnets
  • 1 AA battery
  • 14-18-gauge non-insulated copper wire
  • Needle-nosed plier
  • Wire cutter
  • 12” ruler

For the Racing Battery

  • AA battery
  • 2 different size neodymium disc magnets
  • Tin foil

What Mystery Are We Solving?

What makes different shaped wires spin in a circle around the battery? Why does the racing car battery move in a straight line or circle depending on where the magnets are placed?

Safety Issues

Teenagers could create the experiment on their own but younger kids should be assisted. Adult supervision is recommended since the copper wire may get hot and the neodymium magnets are small and can be accidentally swallowed if placed in a mouth.

How To/Directions

Magic Moving Copper Wire

  1. Cut 6-8” pieces of copper wire.
  2. Create different shapes with the copper wire (spiral, square or a dancer)
  3. Attach 2 neodymium magnets to the bottom (negative terminal) of the AA battery.
  4. Place the magnets with battery vertical on a level surface.
  5. Place the shaped copper wire around the battery with the open ends touching the magnets and the top of the shape touching the top (positive terminal) of the battery.

Racing Car Battery

  1. Roll out tinfoil on a level surface for the length of the racetrack.
  2. Attach the neodymium magnet to the end of the battery.
  3. Set down on the tinfoil.
  4. Let go when the race starts and see how the battery races without assistance to the end of the tinfoil racetrack.
  5. Place a larger magnet on the one end of the battery and a smaller one on the other end. Now the ‘racing car’ races in circles.

What Just Happened In This Homopolar Motor Science Experiment?

A homopolar motor is an electric motor that uses direct current to power rational movement. With the racing car battery, the electric current moves from the positive terminal of the battery to the negative terminal and then through the magnet.

The magic moving copper wire is created when the electricity flows from the positive terminal of the battery through the copper wire to the negative terminal, making a complete circuit. The magnet also has a positive and negative end. The force of the magnet’s magnetic field repels the electric current causing the wire to spin.  

The electromagnetic force is called the Lorentz force.

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