Jumping ring experiment: effect of temperature, non-magnetic material and applied current on the jump height

摘要

The jumping ring experiment is an outstanding demonstration of Faraday's laws of electromagnetic induction and also of Lenz's law. A conducting non-magnetic ring is placed over the extended vertical core of a solenoid. When ac power is applied to the solenoid, the ring is thrown off or held in a state of levitation. This phenomenon happens because the induced current in the ring flows in the direction to counter that of the solenoid current. Consequently, two magnetic fields repel each other, giving rise to the jump effect. The induced current is corresponding to the jump height of a ring. In this work, the jump heights of brass, copper and aluminium rings subjected to different parameters such as temperature, vertical length of ring and applied solenoid current were investigated.