Gauss’s law states that the net flux (a flux into a spherical surface positive, out of the surface positive) through an arbitrary closed surface is equal to net electric charge contained within the surface divided by εo, permittivity constant. Below is a pictorial representation of two charges contained within some surfaces. These surfaces are represented by their two dimensional projections onto the plane (paper), therefore, they appear like closed lines.

Φ1=Flux through S1 is (-5Q)/
εo= -5Q/ εo
Φ2=Flux through S2 is (-5Q+7Q)/
εo=2Q/ εo
Do the following exercise. Find the fluxes through the surfaces provided due to charges shown.
