PURPOSE: To illustrate RL time constant.

DESCRIPTION: A resistance box and an air-core coil are used in an RL circuit. The inductance of the air-core coil can be calculated (if desired) and the time constant L/R calculated from the inductance and the resistance of the box. This can be compared with the experimental result. The signal source, a square wave of about 2000 Hertz, is displayed on the upper trace, and the current in the RL circuit on the lower trace. See circuit below.

SUGGESTIONS:

REFERENCES: (PIRA 5J20.10)

EQUIPMENT: Decade resistor box, circular air-core coil from K2-27, oscillator, wires, and dual trace scope on scope/TV cart.

SETUP TIME: 5 min.