Things to Note
1. Due to the resistance within the rings, the induced current flowing through them will cause them to heat up. A ring held near the coil quickly becomes too hot to hold. A ring clamped near the coil will become hot enough to boil water or melt the PVC pipe.
2. The core was segmented and wrapped in heat shrink in an attempt to reduce the induced currents formed within the core itself. Ideally, every iron rod would be insulated from every other iron rod.
3. Wire nuts were used to connect the coil to the rest of the circuit in order to make it easily removable. You can easily experiment with different coils using the same base.
4. A metal hose clamp was not used to secure the PVC pipe to the base because the currents induced within the hose clamp would quickly melt the PVC pipe.
5. While the same size as the copper ring, the aluminum ring is less dense and, therefore, less massive. It's internal resistance, however, is higher than the copper ring's. Will it jump higher or lower than the copper ring?
6. Why doesn't the split aluminum ring jump at all? Why doesn't it get hot when it is held near the coil?