Field Visualization
Permittivity of Free Space
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.
Value
8.854 × 10⁻12
F/m (Farads per meter)
Uncertainty
≈ 0 (exact, defined)
Fundamental Equations
ε₀| Equation Name | Formula |
|---|---|
| Coulomb's Law', equation: 'F = (1/4πε₀) × (q₁q₂/r₂) | |
| Capacitance | C = ε₀A/d |
| Wave Speed | c = 1/√(ε₀μ₀) |
Applications
Capacitor design, electromagnetic wave propagation, antenna theory
Field Visualization
Permeability of Free Space
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.
Value
1.257 × 10⁻⁶
H/m (Henries per meter)
Uncertainty
≈ 0 (exact, defined)
Fundamental Equations
μ₀| Equation Name | Formula |
|---|---|
| Magnetic Field | B = (μ₀I/2πr) |
| Inductance | L = μ₀N2A/l |
| Force between wires | F/L = (μ₀I₁I₂/2πd) |
Applications
Inductor design, transformer cores, magnetic field calculations
Field Visualization
ε₀-μ₀ Relationship
The product of permittivity and permeability determines the speed of light in vacuum. This fundamental relationship connects electromagnetism to special relativity.
Value
299,792,458
m/s (meters per second)
Uncertainty
0 (exact, defined)
Fundamental Equations
c = 1/√(ε₀μ₀)| 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) |
Applications
Wave propagation, optics, relativistic electromagnetism