Capacitor Energy & Charge Calculator
Calculate capacitor energy and charge with multiple unit options
Capacitor Energy & Charge: Energy Storage Guide
Calculate the energy stored in a capacitor and understand the principles of capacitive energy storage with practical examples.
What is a Capacitor?
A capacitor is an electronic component that stores electrical charge and energy in an electric field. It consists of two conducting plates separated by an insulating material (dielectric).
Energy Storage Formulas
Main Energy Formula
Where:
- E = Energy in Joules (J)
- C = Capacitance in Farads (F)
- V = Voltage in Volts (V)
Alternative Energy Formulas
Where:
- Q = Charge in Coulombs (C)
Charge Formula
Practical Example
Energy Calculation
Given:
- Capacitance (C) = 300 μF = 3×10⁻⁴ F
- Voltage (V) = 20 V
Energy Stored:
E = ½ × 3×10⁻⁴ F × (20 V)² = 60 mJCharge Stored:
Q = 3×10⁻⁴ F × 20 V = 6 mCLC Circuits
Energy Transformations
In an LC circuit (inductor-capacitor circuit):
- The capacitor’s potential energy continuously transforms into the inductor’s magnetic energy
- This oscillation occurs at the circuit’s resonant frequency
- Common applications include signal processing and radio communication
FAQs
How does a capacitor store energy?
A capacitor stores energy in the form of electrostatic potential energy between its plates. When charged, it maintains an electric potential difference due to the separation of positive and negative charges.
Why is the energy formula divided by two?
The factor of ½ appears because the charging process is not ideal. The voltage across the capacitor increases linearly from 0 to V as it charges, resulting in an average voltage of V/2 during the charging process.
What affects a capacitor’s energy storage capacity?
The energy storage capacity depends on:
- Capacitance value (determined by plate area and separation)
- Applied voltage (higher voltage means more energy)
- Dielectric material properties
