Metal ring for performing Thomson’s ring experiment in conjunction with the mains coil (U84974020-230 and U84974020-115 respectively) and the transformer core D (U8497180). First the metal ring is fitted around one stem of a U core and allowed to rest on the mains coil. The stem of the U core is extended by the yoke positioned vertically on top of it. When the mains coil is switched on the ring jumps into the air. Diameter: 55 mm