Electrostatic Potential & Capacitance
Class 12 · Electrostatic Potential & Capacitance
Energy Stored in Capacitor
U = ½CV². Visualized as triangular area under Q-V curve.
Key Notes
01
Charging a capacitor stores energy in the electric field.
02
U = ½CV² = ½QV = Q²/(2C). All three forms are equivalent.
03
Energy density u = ½ε₀E² (in vacuum) — energy lives in the field, not the plates.
Formulas
Energy
Equivalent forms.
Energy density
Energy per unit volume in field.
Important Points
Why ½ and not 1: charge is added gradually as V grows from 0 to V_final.
When two charged caps are connected, energy is generally lost as heat/EM radiation.
Energy Stored in Capacitor notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 12 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.