College of Liberal Arts & Sciences
5K20.30 - Lenz's Law - Jumping Rings
Video Credit: Jonathan M. Sullivan-Wood.
Connect the electromagnet coil to a Variac. Insert the iron core and place a ring over the core. As you turn up the Variac the ring will appear to float. Use a split ring or non-ferromagnetic ring and observe no effect. Unplug the coil from the Variac and plug it into the pulse switch. This allows you to input 110 volts AC instantaneously. Place a ring over the core and hit the switch and the ring will jump about 20 feet into the air.
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- Brian Jones and Matt Fackelman, "Ring Shooter", Don't Forget the Duct Tape, p. 125 - 128.
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