Vernier Software and Technology
Vernier Software & Technology

Using RC Decay to Determine Capacitance


You are designing a power supply for a new GPS vehicle-tracking device to improve vehicle safety and theft recovery. You need to complete your design as soon as possible. You only have one suitable capacitor in your lab, and you suddenly realize that you need to have an accurate knowledge of its capacitance. Unfortunately, you have no capacitance or resistance meters.

But, you do have a collection of five carbon resistors whose values are marked with color bands and are accurate to within ±5%. In addition you have a battery and two types of voltage measuring devices. One is a conventional analog meter (VA) and the other is a computer-based voltage sensor (VC).


In this activity, you will

  • Use measurements of the change in the potential difference across a charged capacitor (C) placed in a circuit with a carbon resistor (R) to obtain an accurate value of capacitance.

Software for Experiment

This experiment uses Logger Pro software for video analysis. The video for analysis is included with the lab book.

Experiment 31 from Physics with Video Analysis Lab Book

<em>Physics with Video Analysis</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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