Levitating Disk Above Rotating Disk
A small magnet is attached with tape to the end of a flexible, plastic ruler. It is held just above a metal disk which can be set into rotation by a turntable. As the disk speeds up, the magnet is first pulled (mostly) in the direction of the disk's motion underneath the magnet. This is due to the friction drag force. Then at higher speeds the magnet is also noticeably pushed upwards away from the disk. This is due to the levitation force. Both of these forces arise from eddy currents induced in the metal disk as a consequence of Lenz's law. If the magnet is moving above but parallel to a flat conductor, the ensuing magnetic levitation at higher speeds has been studied as a novel way to move trains
| Equipment | Storage |
|---|---|
| DC power supply | 021-16B |
| Rotating disk on a motor | 021-17C |
| Magnet taped to a stick or ruler |
Unfortunately, there are no media for this demo. :(