The capability of vacuum to permit electric field lines. Also known as the electric constant or dielectric constant of vacuum. Fundamental to Coulomb's law and capacitance calculations.
| Equation Name | Formula |
|---|---|
| Coulomb's Law', equation: 'F = (1/4πε₀) × (q₁q₂/r₂) | |
| Capacitance | C = ε₀A/d |
| Wave Speed | c = 1/√(ε₀μ₀) |
Capacitor design, electromagnetic wave propagation, antenna theory
The measure of resistance of vacuum to magnetic field formation. Also called the magnetic constant. Defines the strength of magnetic field produced by electric current.
| Equation Name | Formula |
|---|---|
| Magnetic Field | B = (μ₀I/2πr) |
| Inductance | L = μ₀N2A/l |
| Force between wires | F/L = (μ₀I₁I₂/2πd) |
Inductor design, transformer cores, magnetic field calculations
The product of permittivity and permeability determines the speed of light in vacuum. This fundamental relationship connects electromagnetism to special relativity.
| Equation Name | Formula |
|---|---|
| Speed of Light | c = 1/√(ε₀μ₀) |
| Impedance of Free Space | Z₀ = √(μ₀/ε₀) ≈ 377 Ω |
| Energy Density | u = 1/2(ε₀E2 + B2/μ₀) |
Wave propagation, optics, relativistic electromagnetism