5H40.10-Parallel Wires


Video: Watch this demo | Demo #2

MIT demo video

Description: This demonstration shows the interaction of current passing through parallel wires.
The wires with current directed in the same direction will come closer together, while the wire with current going in opposite directions will spread apart.


  • Two Sets of Parallel Wires
  • Two Stands
  • 12V Battery
  • Three Way Switch
  • Large Switch
  • Wires
  • Whiteboard

Setup Procedure:

  1. Attach the two sets of parallel wires to the stands
  2. Connect the battery and switches to the parallel wires as shown in the circuit diagram above. All wires except the parallel wires themselves should be “doubled”, as seen in the pictures above.
  3. Place the whiteboard behind the parallel wires; this will make it easier to see.

Demonstration Procedure:

  1. Flip the three way switch to the set of wires that you want to demonstrate.
  2. Flip the big switch to on, and then flip it off a few seconds later.


  • There’s a high current running through the wires; wearing the safety gloves is advised
  • The wires get hot quickly, and will melt if left on for too long, so it’s important that you only leave the circuit on for a few seconds at a time.
  • When setting up the demonstration, plug in the battery last, and when taking it down, unplug the battery first.