Gauss’s Law relates electric flux () on a surface (S) to the enclosed charge (Q):
See also Wikipedia:Gauss’s_law.
Gauss’s law is closely related to the Poisson Equation (and Laplace Equation), used by SIMION Refine. Gauss’s law is also sometimes useful for Charge-Capacitance Calculation.
Gauss’s Law for Magnetism¶
Related formulas exists for magnetic fields, but the right-hand-side is always zero assuming magnetic monopoles don’t exist:
See also Wikipedia:Gauss%27s_law_for_magnetism.