PURPOSE: Apply Kirchhoff's laws to a simple two-loop problem.

DESCRIPTION: The circuit is mounted on an overhead projector projectual to make it visible to a class. Analysis can be carried out using the two loops of the circuit to obtain the current in each part of the circuit. An analysis sheet can be used on another overhead projector. Finally, the voltmeter mounted on the circuit projectual can be used to measure the voltage drops across various parts of the circuit, checking the results of the calculations. Use a digital voltmeter to read small voltage drops more accurately.

SUGGESTIONS: This demonstration involves a good bit of detail, and as such requires practice before class and a significant amount of class time.

REFERENCES: (PIRA 5F20.10) See Demonstration Reference File for analysis of the circuit.

EQUIPMENT: Kirchhoff's laws apparatus with 1.5 volt and 7.5 volt batteries, digital voltmeter, and analysis transparency.

SETUP TIME: 5 min.

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