CH.4 Relation between permittivity of free space, permeability of free space and speed of light.

1. One of the most important results of electromagnetic theory is the relationship between the permittivity of free space (ε₀), permeability of free space (μ₀), and the speed of light (c). c= 1/ square root of permittivity ×permeability of free space Where: c = Speed of light in vacuum = 3×10⁸m/s μ₀ = Permeability of free space = 4pi×10-⁷H/m ε₀ = Permittivity of free space = 8.85 ×10-¹²F/m This equation was derived by James Clerk Maxwell, who showed that light is an electromagnetic wave. It reveals that the speed of light depends only on the electrical and magnetic properties of free space. Key Points: Higher permittivity or permeability results in a lower wave speed. The relation confirms that light is an electromagnetic wave. It forms the foundation of electromagnetic wave theory and modern communication systems.