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Electricity & Magnetism
Electricity & Magnetism

Energy Density (Magnetic Field)

u=B22μ0u = \frac{B^2}{2\mu_0}

Energy stored per unit volume in a magnetic field.

Variables

u
Energy density
Energy per unit volume
J/m³
B
Magnetic field
Field strength
T
μ₀
Permeability
4π×10⁻⁷
H/m

Derivation

From U = ½LI² and B = μ₀nI, u = B²/(2μ₀).

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Common questions

What is the Energy Density (Magnetic Field) formula?

Energy Density (Magnetic Field) is written u = B²/2μ₀. Energy stored per unit volume in a magnetic field. It belongs to Electricity & Magnetism, under Magnetism.

What are the units in u = B²/2μ₀?

In SI units, u is energy density, measured in kg/(m·s²); B is magnetic field, measured in kg/(A·s²); μ₀ is permeability, measured in kg·m/(A²·s²).

How is the Energy Density (Magnetic Field) formula derived?

From U = ½LI² and B = μ₀nI, u = B²/(2μ₀). The result is u = B²/2μ₀.