Electricity & Magnetism
Energy Density (Electric Field)
Energy stored per unit volume in an electric field.
Variables
uJ/m³
Energy density
Energy per unit volume
In SI units: kg/(m·s²)
Allowed values: 0 or more
ε₀F/m
Permittivity
8.85×10⁻¹²
In SI units: A²·s⁴/(kg·m³)
Allowed values: greater than 0
EN/C
Electric field
Field strength
In SI units: kg·m/(A·s³)
Derivation
From U = ½CV² and C = ε₀A/d, u = U/Volume = ½ε₀E².
Your notes
0/5000
Constants in this formula
Check value
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- ε₀ = 8.854 × 10⁻¹² F/m (Permittivity)
- E = 2 N/C (Electric field)
Result: u = 1.7708 × 10⁻¹¹ J/m³
Other electricity & magnetism formulas with the same quantities
- Parallel Plate Capacitor (Capacitance) shares Permittivity
- Capacitor with Dielectric (Capacitance) shares Permittivity
- Electric Field (Electrostatics) shares Electric field
- Gauss's Law (Electrostatics) shares Permittivity
- Electric Dipole Field (Axial) (Electrostatics) shares Electric field
- Electric Flux (Electrostatics) shares Electric field
Where this formula is listed
- Electricity & Magnetism formulas, under Capacitance, alongside Capacitance, Capacitors in Series, Capacitors in Parallel and RC Time Constant.
- In the electricity & magnetism list it comes after Capacitor with Dielectric and before Magnetic Force on Charge.
- Electricity & Magnetism formula sheet, one of 48 formulas printed with symbol keys and SI units.
- The full formula index, grouped by category and topic.
Common questions
What is the Energy Density (Electric Field) formula?
Energy Density (Electric Field) is written u = (1/2)ε₀E². Energy stored per unit volume in an electric field. It belongs to Electricity & Magnetism, under Capacitance.
What are the units in u = (1/2)ε₀E²?
In SI units, u is energy density, measured in kg/(m·s²); ε₀ is permittivity, measured in A²·s⁴/(kg·m³); E is electric field, measured in kg·m/(A·s³).
How is the Energy Density (Electric Field) formula derived?
From U = ½CV² and C = ε₀A/d, u = U/Volume = ½ε₀E². The result is u = (1/2)ε₀E².