Force on a current carrying wire in a magnetic field.

Force on a current carrying wire in a magnetic field. A vertical thick copper wire is suspended between the poles of a permanent horseshoe magnet. When a 'reversing switch' is thrown, current of about 4 amps is sent through the wire in one direction. The magnetic field generated around the wire opposes (or attracts) the field of the horseshoe magnet, causing the wire to swing to the left (or right). Throwing the switch in the opposite direction causes current to flow in the opposite direction, and the wire swings the opposite way. A Timer Box reminds the demonstration operator to turn off the apparatus in 5 seconds to avoid melting the wires