5H40.30-Jumping Wire

Video: Watch this demo

Instructor’s video

Description: This demonstration shows the interaction between the moving current in a wire in the presence of a magnetic field.


  • Large DC power supply/ car battery
  • Strong permanent magnet
  • Jumping wire apparatus
  • Portable Metal post with clamp
  • 4 Banana plug wires

Setup Procedure:

  1. Connect the jumping wire apparatus to the portable metal post clamp.
  2. Take the protective plug out of the magnet. Use caution.
  3. Position the jumping wire apparatus so the wire can go between the two poles of the magnet (see picture).
  4. Connect the jumping wire apparatus to the power supply. Use two cables in parallel per terminal due to high current.
  5. Turn switch on to test circuit to see if it is working.
  6. When the professor is done, place the plug back into the magnet. Use caution.

Demonstration Procedure:

  1. Turn on the power supply with the switch open.
  2. Close the switch and note that the wire moves either up or down. This is because the current carrying wire produces a magnetic field which interacts with the permanent magnet, thus creating a force.
  3. You may reverse the switch to show that the wire moves in the opposite direction.
  4. When finished, turn off the power supply.

Strong magnetic field
This is a very powerful permanent magnet. Use caution.