Sample Problems to calculate Electric Flux 01. A point charge of 1.8mC is at the centre of a cubical Gaussain surface having each side 50cm. What is the net electric flux through the surface? Suggested answer: According to Gauss' theorem, flux = q / sigma sub0 or 1.8mC/8.854 x 10^-12 I would question if this is true no matter WHERE inside the cubical Gaussian surface the charge is. If it does matter, why is there no varible for the position inside a given surface????