where <math>\Phi</math> is the electric potential (flux), <math>\vec{E}</math> is the [[electric field]], <math>\mathrm{d}\vec{A}</math> is a differential area on the closed surface ''S'' with an outward facing [[surface normal]] defining its direction, <math>Q_\mathrm{A}</math> is the charge enclosed by the surface, <math>\rho</math> is the charge density at a point in <math>V</math>, <math>\varepsilon_o</math> is a constant for the [[permittivity]] of free space and the integral <math>\oint_S</math> is over the surface ''S'' enclosing volume ''V''. | where <math>\Phi</math> is the electric potential (flux), <math>\vec{E}</math> is the [[electric field]], <math>\mathrm{d}\vec{A}</math> is a differential area on the closed surface ''S'' with an outward facing [[surface normal]] defining its direction, <math>Q_\mathrm{A}</math> is the charge enclosed by the surface, <math>\rho</math> is the charge density at a point in <math>V</math>, <math>\varepsilon_o</math> is a constant for the [[permittivity]] of free space and the integral <math>\oint_S</math> is over the surface ''S'' enclosing volume ''V''. |