Jumping Ring 1

The apparatus operates on 120V AC and draws significant current. Ensure all connections are secure and keep liquids away from the device. Do not touch the coil or metal components while the apparatus is energized.

Rings can jump 2-3 meters at room temperature and may reach ceiling height (4+ meters) when supercooled. Ensure adequate clearance above the apparatus and warn students that rings will be launched upward. Do not place hands or face above the apparatus during operation. Consider using safety glasses if ceiling height is limited.

When using liquid nitrogen, handle cold rings only with insulated gloves and tongs. Supercooled rings can cause severe frostbite on contact. Ensure proper ventilation when using liquid nitrogen in enclosed spaces. Do not attempt to catch falling rings without thick protective gloves. Allow rings to warm completely before student handling.

Purpose

Demonstrates Faraday's Law, Lenz's Law, and eddy currents. AC current through a solenoid induces currents in conducting rings that create opposing magnetic fields, launching the rings upward. Comparing solid vs. slit rings shows that a complete conducting path is required for the effect.

Jumping ring apparatus with copper solenoid coil wound around a white insulating column, mounted between clear acrylic plates with threaded rods. Four rings displayed at the base: aluminum ring with slit, thick copper ring, and solid aluminum ring

Figure 1: The jumping ring apparatus with its solenoid coil and interchangeable rings. Left to right: aluminum ring with slit, thick copper ring, solid aluminum ring. The slit ring will not jump because current cannot circulate.

Extra Parts for Jumping Ring

1

Warning: Electrical Safety

Warning: Projectile Hazard

Danger: Cryogenic Hazards

Purpose

Safety Warnings

Warning: Electrical Safety

Warning: Projectile Hazard

Danger: Cryogenic Hazards

Purpose