20. Big Sparks

Impressive sparks are produced when various capacitors are discharged.

A 4000 F capacitor is charged to 150 V. It can then be carried close to the class and snapped in front of them. This is guaranteed to wake up the sleepers!

A Leyden jar is charged to 50,000 V with a Van de Graaff generator. It can even be disassembled and the outer and inner cans touched together, and then reassembled (carefully! ). Now, when the outer and inner cans are bridged by a discharge wand, a half-inch spark jumps. (See E.1.5).

Wire exploder: A 175 F capacitor is charged to 4000 V and discharged through a small wire. The wire vaporizes with a large bang and flash. This demonstration is dangerous and must be performed by a lecture demonstration staff member.