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Energy Stored in a Capacitor

<^< Charge Capacitance and Voltage | Course Index | Examples: Capacitance >^>

Graph of energy storage related to charge and voltage

The energy stored in a capacitor is the area under the graph of charge (Q) plotted against voltage (V). This area is given by:

Since Q = CV:

Area = ½ (CV) x V

Thus the energy stored in a capacitor is proportional to the product of the capacitance and the square of the potential difference, i.e.

E = ½ C V²

where E is the energy (in Joules), C is the capacitance (in Farads), and V is the potential difference (in Volts).

<^< Charge Capacitance and Voltage | Course index | Examples: Capacitance >^>