MIT Physics Demo - Lenz's Law with Copper Pipe

A magnet is dropped down a conducting copper pipe and feels a resistive force.  The falling magent induces a current in the copper pipe and, by Lenz's Law, the current creates a magnetic field that opposes the changing field of the falling magnet.  Thus, the magnet is "repelled" and falls more slowly.

credit

MIT Department of Physics Technical Services Group

license

MIT TechTV