Objective:
– To show the effects of a moving magnetic field opposing Eddy Currents induced in a hollow copper pipe.
Apparatus:
- Copper pipe
- Copper, aluminum and iron cylinders
- Neodymium magnet
Method:
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- The copper tube is clamped vertically
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- The copper, aluminum and iron cylinders are dropped through the tube, with no effect.
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- The Neodymium magnet is then dropped through the tube.
Observe that:
- The magnet slows down, arriving at the end after a noticeably longer time than with the cylinders.
The moving magnet has induced circulating currents whose own magnetic field opposes that of the magnet.
Eddy Currents Induced by a Linearly-Moving Magnet
– Video Created at Utah State University by Professor Boyd F. Edwards and assistants.
Note: in the video an aluminum pipe (which is also non-magnetic) is used instead of a copper pipe.