Additional Info

• ID Code: K1-03
• Purpose: Demonstrates force on a current-carrying wire in a magnetic field
• Description:
  A wire (reinforced by a plastic tube for safety) passes between the pole tips of a strong magnet. When the key is pressed so that current flows in the wire, the wire jumps out from between the pole tips.

  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 the leads 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 K1-04 in this section for a more portable version of this experiment.

• Availability: Available
• References: REFERENCES: (PIRA 5H40.30)
• Loc codes: K1
• Videos-1: Video of demonstration