Equipment: A strip of aluminum foil, a 6V battery, one to four homemade horseshoe magnets, two brass weights and two patch cords.

What it does: When conducting, the aluminum foil strip ‘jumps’ up or down in the magnetic field.

Concepts Demonstrated: The force on a current carrying conductor in a magnetic field.

Classroom assembly:

1. Unroll the strip of aluminum foil on the bench top.
2. Place a brass weight on each end. Adjust the weights so there is slack in the aluminum foil.
3. Place the magnets over the strip as desired.
4. Plug the patch cords into each brass weight and connect one patch cord to the 6V battery.
5. Connect the other patch cord to the battery temporarily to show the foil 'jump' in the magnetic field.

• The red pole is north and the blue pole is south.

Cautions:

• The aluminum foil becomes hot over time and the battery loses power quickly. Do not leave connected for longer than necessary.
• The Aluminum foil is delicate. Handle with care.

Setup Time: Short.

Difficulty: Straightforward.

Visibility: Medium. This demonstration can be seen by most people in a large lecture theater.

Related demonstrations:

References:

Original Construction: The current carrying strip of aluminum foil is approximately 30" long x 0.5" wide and was cut from the edge of a roll. The horseshoe magnets were made in house by affixing a permanent magnet between two soft iron poles. The magnet/pole fixture is held in place by a brass top plate.