Purpose
In this experiment, students will arrange a simple circuit involving a power source and a resistor. They will attach an ammeter and a voltmeter to the circuit. They will measure corresponding values of current and voltage in the circuit. They will then interpret observations to find the relationship between current, voltage, and resistance.
Discussion
The current, voltage, and resistance in an electric circuit are related to one another in a very specific way. Designers of electric circuits must take this relationship into account or their circuits will fail. This relationship is as important and fundamental in electricity as Newton’s second law of motion is in mechanics. In this experiment, you will determine this relationship
Required Equipment
Variable DC power supply (0–6 V), 2 power resistors with different resistances (values between 3 Ω and 10 Ω recommended), power resistor with unknown resistance (for the Going Further section of experiment), miniature light bulb in socket (14.4-V flashlight bulb recommended), DC ammeter (0–1 A analog recommended), DC voltmeter (0–10 V analog recommended), 5 connecting wires, graph paper
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Student Worksheet Teacher Notes
The "Graph Paper" required for this lab is readily available at your office or school supply store. Each lab group would need access to enough for each student. See lab detail for specific use.
