Abstract
A magnet floats above a superconductor.
Portable
Yes
Principles Illustrated
Meissner Effect (expulsion of magnetic field by a superconductor).
Video
Probably this will be at most 20 hours of work in total.
Download video (right-click and “save link as”):
Floatingmagnet.m4v
NCEA & Science Curriculum
PHYS 3.6
Instructions
Cool a superconducting disk with liquid nitrogen and lower the magnet over the superconductor. Alternatively, put the magnet on top of the warm superconductor and cool. The magnet will pop up.
Safety
If you are not trained to use liquid nitrogen and confident with it, contact a university physics or chemistry department for help. Wear liquid nitrogen safety gear, particularly goggles, and use plastic forceps to handle the magnet. Only a few ml of liquid nitrogen are needed to cool the superconductor.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
Related Resources
- How Cold is Liquid Nitrogen
- Floating Skier
Teaching Resources
Would you like to contribute lesson suggestions? Contact us.
References
Our superconductor was made in a research lab, but similar materials and instructions can be obtained commercially.
Credits
This teaching resource was developed with support from
The MacDiarmid Institute
Faculty of Science, Victoria University of Wellington
School of Chemical and Physical Sciences, Victoria University of Wellington