5H50.20-Force on a Current Loop

Video: Watch this demo

Instructor’s video

Description: This demonstration shows the force on a current carrying wire loop in a magnetic field.


  • Large DC power supply
  • Current Loop apparatus
  • 2 Bar magnets
  • Electric magnetizer
  • 4 Banana plug cables

Setup Procedure:

  1. Use the electric magnetizer to magnetize the two bar magnets.
  2. Place the two magnets on their posts as shown in the picture.
  3. Connect the Current loop apparatus to the power supply using two cables in parallel per terminal.

Demonstration Procedure:

  1. With the switch open, turn on the power supply.
  2. Close the switch and note that the wire loop spins.
  3. If you move the switch to the opposite direction, the current is reversed and the wire loop will spin in the other direction.
  4. When finished, turn off the power supply.