Levitating Magnet

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

Copyright

Copyright and fair use statement