e&m.jpg (12862 bytes)

Arago's Disk

EQUIPMENT
    redball.gif (326 bytes) Brass Disk
    redball.gif (326 bytes) Rotator
    redball.gif (326 bytes) Small Horseshoe Magnet


NARRATIVE
       The EMF induced in a rotating conducting disk in a magnetic field produces a counter force (due to eddy currents) on the magnetic field.  Rotate the brass disk under the suspended small horseshoe magnet. The magnet is forced to rotate in the same direction as the magnet.