PURPOSE: To show that the forces on a current loop inserted in a magnetic field are determined by the direction of the current wrt the direction of the B field.
DESCRIPTION: A floppy wire loop, shown in the photo above, is inserted into a magnetic field. A power supply is switched on to provide a current through the loop. If the wire loop is oriented in one direction and the current is switched on, the circular shape of the wire loop is maintained. If the orientation of the wire loop is reversed and the current is swicthed on, the loop will not maintain its circular shape. Instead, the circular shape of the loop will distort as it feels a force to flip around the directionof the current flow in the B field.
EQUIPMENT: Balloon is stored in the general use cabinet.
SETUP Notes: Use the low voltage power supply to provide about 10 amps of current. The swicth on the power supply is used to turn on and off the current. The wire loop cannot be made from stiff wire. A light source and camera is used to project the action of the current loop to the class, as shown below.
Updated by Jun Qi in 3/13/2000