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Electricity & Magnetism
Electricity & Magnetism

Capacitor Energy

U=12CV2=Q22CU = \frac{1}{2}CV^2 = \frac{Q^2}{2C}

Energy stored in charged capacitor.

Variables

U
Stored energy
Energy in capacitor
J
C
Capacitance
Capacitance
F
V
Voltage
Potential difference
V
Q
Charge
Stored charge
C

Derivation

U = ∫V dq = ∫(q/C) dq = Q²/(2C) = ½CV².

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Common questions

What is the Capacitor Energy formula?

Capacitor Energy is written U = 1/2CV² = Q²/2C. Energy stored in charged capacitor. It belongs to Electricity & Magnetism, under Capacitance.

What are the units in U = 1/2CV² = Q²/2C?

In SI units, U is stored energy, measured in kg·m²/s²; C is capacitance, measured in A²·s⁴/(kg·m²); V is voltage, measured in kg·m²/(A·s³); Q is charge, measured in A·s.

How is the Capacitor Energy formula derived?

U = ∫V dq = ∫(q/C) dq = Q²/(2C) = ½CV². The result is U = 1/2CV² = Q²/2C.