5K40.80 Hand Crank Flashlight
Concepts
Electromagnetic induction, conservation of energy, Faraday's law
Overview
A magnet mounted on a flywheel spins when the handle is squeezed, changing the magnetic flux and generating an EMF that illuminates a light bulb.
Details
Equipment
- [1] Squeeze flashlight
Important Notes
- For large lectures, a camera would be useful for showing the internal structure of the hand crank flashlight.
Script
- For a large lecture, dim the lights.
- Squeeze the handle repeatedly until light bulb turns on.
Additional Resources
References
- PIRA 5K40.80
Disclaimer
- Don't attempt this at home!
Last revised
- 2023
Technicals
- Original construction: purchased. The flashlight contains a coil and a rotating magnet.
Related AV
Related demos
- Forever 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.