The surface charge density on a solid is defined as the total amount of charge q per unit area A,
The surface charge on a surface S with surface charge density is therefore given by
In cgs, Gauss's law requires that across a boundary
where is the electric field in medium i and is the unit normal vector, which is equivalent to
where is the voltage in medium i. Similarly, in MKS,
where is the permittivity of free space, and
In a dielectric, the so-called bound surface charge density is given in MKS by
where P is the electric polarization.
Bound Surface Charge Density, Charge, Electric Polarization
