Capacitance
Topics
E&M Topics
-
Capacitance
-
Combination of capacitors
Equipment List
Introduction
This lab has two parts.
The purpose of Experiment 1 is to investigate how capacitance depends on separation of the two plates of the capacitor. In this part you will have two fixed plates for which you will vary the distance between. As a result, you will be able to observe the change in capacitance.
The purpose of Experiment 2 is to measure the different capacitance for connections in parallel and series. Using a multimeter you will be able to analyze the change in capacitance for a circuit with two and three capacitors in series and parallel.
Background
The capacitance C of a capacitor is defined as the ratio of the magnitude of the charge on either conductor to the magnitude of the potential difference between the conductors.
For two parallel plates of equal area and separated a certain distance, the capacitance is defined as
A being the area, d being the distance, and ε being the permittivity of the medium between the plates.
Combination of Capacitors
In series the inverse of the equivalent capacitance is the algebraic sum of the inverse of the individual capacitances, and it is always less than any individual capacitance of the combination.
( 2 )
=
+
+
In parallel the equivalent capacitance is the algebraic sum of the individual capacitances and it is always greater than any of the individual capacitances.
( 3 )
Ceq =
C1 +
C2 +
C3 
