Demonstrates: Potential affected by a resistor. Description: Description: A rheostat is used as a voltage divider to show how to produce any voltage up to the maximum of the source.
Demonstrates: Resistance. Description: A small bulb is attached to powersupply by a coil of copper wire. After coil of wire is placed in liquid nitrogen the bulb becomes brighter due to decreased resistance. Put coil in boiling water to increase resistance.
Demonstrates: High voltage phenomenon. Description: High voltage from a transformer is applied to electrodes. The narrow spacing at the bottom promotes electrical breakdown of the air. The conducting path of the discharge heats up and rises.