## ELECTROMAGNETIC FIELDS AND WAVES

Engineering Bot March 13, 2021

Gauss’s law relates an electric field to the charge(s) that create(s) it. The field (E) points towards negative charges and away from positive charges, and from the microscopic perspective, is related to charge density (ρ) and vaccuum permittivity (ε0, or permittivity of free space) as:

$\mathrm{\nabla }\cdot \mathbf{\text{E}}\mathbf{=}\frac{\rho }{{ϵ}_{\mathbf{0}}}$

Gauss’s Law basically says that a net amount of charge contained within a region of space will generate an electric field that emanates through the surface that surrounds that region.