Vernier Software and Technology
Vernier Software & Technology

Parallel Plate Capacitor: Potential Difference vs. Spacing

Introduction

A capacitor is defined as any two conductors, separated by an insulator where each conductor carries a net excess charge that is equal in magnitude and opposite in sign. Its capacitance, C, is defined as

C \equiv \frac{Q}  {V}

where Q is the magnitude of the excess charge on each conductor and V is the voltage (or potential difference) across the plates.

We can use Gauss’ Law to analyze a parallel plate capacitor if we assume that most of the electric field lines are perpendicular to the plates. According to Gauss, if air is the insulator, the capacitance, C, is related to the area of the plates, A, and the spacing between them, d, by the equation

C = \frac{{{\varepsilon _0}A}}  {d}

ε0 is known as the electric constant (or permittivity).

Objectives

In this activity, you will

  • Explore how the voltage (a.k.a. potential difference) across the plates varies as the distance between the charged plates increases.

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
18Oscillations
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 29 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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