What’s Going on?
When you rotate the crank, electricity is produced as indicated by the movement of the voltmeter needle. When you place a finger on a brass plate then rotate the crank, you feel nothing in your finger. When you place two fingers from the same hand on the two brass plates and rotate the crank, you experience a tingling feeling or mild electric shock in your fingers. This indicates that electricity flows through your fingers as in a closed circuit.
Try these other exhibits on Electricity and Magnetism:
Body beat, Circuit, Conductors and Insulators, Electric Fleas, Van De Graaff, Hand Battery, Jacob’s Ladder, Laser harp, Magnetic Repulsion, Magnetic Suction, Pedal power, Photovoltaic Cell, Plasma Sphere, Radiometer, Steady Hand Game, Thompson Ring, Tesla Coil, Video Camera