5K10.25 Inductive Coil with Lamp (Shake Flashlight, Forever Flashlight)

Concepts

Electromagnetic induction, conservation of energy

Overview

As the flashlight is shaken, a magnet passes through a coil of wire connected to an LED, which illuminates.

Details

Equipment

  • [1] Shake flashlight

Script

  1. Dim the lights.
  2. Hold the flashlight horizontally and shake it so the magnet moves through the coil. Shine the light at the audience.

 

Additional Resources

References

  • PIRA 5K10.25

Disclaimer

  • Don't attempt this at home!

Last revised

  • 2020

Technicals

  • Original construction: purchased. The flashlight has had its capacitor and on/off switch removed so that the magnet and coil directly connect to the flashlight bulb.

Related AV

Related demos

  • Hand Crank Flashlight

 

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.