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.

Physics with Video Analysis

See other experiments from the lab book.

1Rolling Ball
2Big and Small: How to Scale an Image
3Velocity Change
4Velocity and Speed
5Velocity and Acceleration
6Three Movies: Determining Constant Acceleration
7Demon Drop: A Mathematical Modeling Activity
8Jumping on the Moon
92D Vectors: Pool Ball Displacement, Velocity, and Speed
10Galileo's Projectile I: Using 17th Century Techniques
11Galileo's Projectile II: Using Contemporary Techniques
12Projectile Motion Vectors
13Frictional Slowing
14Impulsive Juggling
15Center of Mass Motions
16Finding a Spring Constant
17Net Work - Kinetic Energy Theorem
19Slinky Wave Speeds
20Superposition of Slinky Waves
21A Wave Pulse Equation
22Doppler Effect: Surface Water Waves
23Doppler Effect: Sound Waves
24A Heat Engine: Relating Work to the P-V Cycle
25Coulomb's Law for Two Charged Spheres
26Discharge Rate
27Electric Field Due to a Line of Charge
28Resistance and Ohm's Law
29Parallel Plate Capacitor: Potential Difference vs. Spacing
30Wiring Capacitors in Series and Parallel
31Using RC Decay to Determine Capacitance
32Exploring Faraday's Law
33Snell's Law of Refraction

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.

Buy the Book

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