Pendulum in a Magnetic Field

This demonstration shows how eddy currents create an opposing magnet field. As the solid pendulum swings through the magnetic field, eddy currents are produced because of the changing magnetic flux in the aluminum. These currents create a magnetic field opposite of that of the magnet which slows the pendulum. The hollow pendulum does not slow as much because there is not as much area for the eddy currents. Therefore, is a smaller magnetic field to slow the pendulum. The pendulum with the slots does not easily allow for the movement of eddy currents and thus does not slow like the others.

* Equipment seen in the video may vary from equipment used in ND Demonstrations. See information and images below for ND equipment and setup.