How to Find the Charge of a Capacitor

The amount of electric charge that a capacitor holds is dependent upon both storage capacity and voltage.

Capacitors store electric charge when a voltage source is connected to the capacitor. The amount of charge that the capacitor stores depends upon both the storage capacity (measured in farads) of the capacitor, as well as the voltage applied to the capacitor. The total charge (measured in coulombs) stored in the capacitor can be calculated from these two values.

Things You'll Need

• DC voltage source (such as a battery or regulated power supply)
• Pen or pencil
• Paper
• Calculator

Instructions

1. Write down the voltage rating of the voltage source. For example, if the voltage source is a six-volt battery, write down "6 volts."

2. Write down the capacitor rating in farads. If the capacitor value is less than one farad, write down the value in decimal form. For example, if a capacitor is rated for 220 millifarads, write the decimal equivalent of "0.22 farads" down.

3. Multiply the voltage value by the capacitance value. The resulting value is how many coulombs of electrical charge the capacitor will hold in this circuit.

References

• Georgia State University: Capacitors