PURPOSE: To demonstrate the torque on a coil in a magnetic field.

DESCRIPTION: A large coil sits between the poles of a strong horseshoe magnet with the plane of the coil parallel to the magnetic field lines as in the photograph. When a large current pulse is applied to the coil a torque is exerted on the coil by the magnetic field which rotates the coil so that the magnetic field is perpendicular to the plane of the coil. The "power pack" is batteries with a capacitor in parallel to provide a stronger and faster current rise.

SUGGESTIONS:

REFERENCES: (PIRA 5H50.20)

EQUIPMENT: Strong horseshoe magnet, 500-turn coil, and power pack with key.

SETUP TIME: 5 min.