5H40.30 Jumping Aluminum Ribbon
When conducting, a ribbon of aluminum foil "jumps" up or down in a magnetic field.
-  Aluminum foil ribbon
-  Horseshoe magnet
-  6 V battery
-  Telegraph switch
-  Banana cable
-  Insulated alligator clip
-  Alligator clip
-  Brass weight
- Lay out aluminum foil ribbon with brass weights on the ends. Keep some slack in the foil.
- Connect the battery, switch, and foil in series using the cables and clips.
- Place the magnets in the desired configuration.
- Red means a north pole and blue means a south pole.
- If the demo does not work well, try adjusting the amount of slack in the foil.
- When packing up this demo, make sure not to short the battery.
- 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.
- Ask students to predict which way the foil will shift under each magnet.
- Close the switch. The foil should "jump" in the local magnetic field.
- PIRA 5H40.30
- Don't attempt this at home!
- 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.
- Lorentz force between parallel wires
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.