Magnet Falling Through a Coil

As a magnet is dropped through a conducting metal ring, a current is induced in the ring, generating a magnetic field. This induced magnetic field acts on the magnet in such a way as to oppose its motion: as the magnet comes down towards the ring from above, the field tries to push it upwards. As it falls away below the ring, the field tries to pull it upwards. The image and accompanying animation illustrate the fields generated by this effect. The video footage shows it happening in an actual experiment, where the ring has been cooled in liquid nitrogen to allow the induced current to flow more freely.