Additional Info

• ID Code: K1-04
• Purpose: Demonstrate the force on a current-carrying wire in a magnetic field.
• Description:
  A wire is placed or held between the poles of a small horseshoe magnet. When the ends of the wire are connected to a 6-volt battery, the wire jumps out of the magnet. The current in the wire or the orientation of the magnet can be changed to investigate the directions of the vectors involved.

  Engagement Suggestion

  • Once students have seen what happens, encourage them to predict the results of reversing the direction of the flow of current. Then swap it around and show what happens. Have them discuss the results.
  • What if you flip the magnet itself over? Again, have them predict what will happen, then try the experiment and discuss.
  

  Background

  This illustrates the Lorentz force, or Laplace force, as predicted by Maxwell’s equations. A current flowing through a magnetic field experiences a force determined by the cross product of the current vector and the magnetic field.

  
  

  See demonstration K1-03 in this section for a larger version of this demonstration for classrooms.

• Availability: Available