ε₀ is the vacuum permittivity (approximately 8.854 x 10⁻¹² F/m). Differential Form
The law states that the net electric flux through any closed surface is equal to the total enclosed charge divided by the permittivity of free space. The Mathematical Formula Integral Form
Planar Symmetry: Finding the electric field near an infinite sheet of charge. Why Use Gauss's Law?
Cylindrical Symmetry: Determining the field around an infinitely long charged wire or cylinder.
Q_encl is the total electric charge enclosed within the surface.