This Faraday S Plate is an lightning plate used for electrostatic demonstration. Demonstrates how an electric discharge will follow the path of resistance. Even though it is longer than a direct path. A long metallic conductor crosses a 10 x 15 cm. Nonconducting plate. When the ends of the conductor are connected to an electrostatic machine or spark coil , the path of the current is emphasized by sparks across gaps in the conductor.