Capacitance - The Parallel Plate Capacitor

For parallel plate capacitors the capacitance (C) is proportional to the area of each of the conducting plates and inversely proportional to the distance between the plates - as long as the area (A)is much, much greater than the distance between the plates (d) squared.

It is also proportional to the permittivity of the dielectric (). The dielectric is the insulator substance that separates the plates - often that is air.

The capacitance of a parallel-plate capacitor is therefore given by:

When there is a difference in electric charge between the plates, an electric field is created in the region between the plates. The electric field that created is proportional to the amount of charge that has been moved from one plate to the other. This electric field creates a potential difference V between the plates of this simple parallel-plate capacitor.

V = Ed

Other pages you might find interesting...

Capacitors - an introduction

Capacitance - definition and equations

Dielectric

Storing Energy in a Capacitor

Capacitor Discharge

An Experiment to Determine the Capacitance of a Capacitor