When the yoke magnet is rotated, the non-magnetic brass ring appears locked and spins with the motion of the magnet.

The yoke magnet is supported by a ring of ball bearings between the white and red plate, which allows the magnet to spin in the vertical axis.

This is a demonstration for Faraday's and Lenz's Laws. The ring moves to resist the change in flux that is caused by rotating the magnet.

Ensure that the ring is relatively centred within the yoke magnet by moving the thread and adjusting its length if necessary.