College Physics: Gaussís Law Exercise, PHYS 212


Gaussís 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.