Physics Dept. Demonstration Manual

DEM31 - Force on a Current-Carrying Conductor


To show force exerted on a current-carrying conductor in a magnetic field.

  • Swing-mounted conductor
  • Large horseshoe magnet
  • Power supply (Twel)
  • Leads (heavy)


A swing conductor hangs vertically between the poles of a U- shaped permanent magnet. When the power supply is turned on and the output is gradually increased, the conductor will be repelled at greater angles from the permanent magnetic field. Switching the supply off and on will cause an instant deflection from vertical.


To create the desired outward deflection, observe the polarities marked.