Slide 7 of 11
Notes:
Gauss’s Law turns out to be a consequence of the “inverse square” mathematical form of Coulomb’s Law. It is a very helpful law in computing the precise filed in certain cases where the charges creating the field are very symmetrically arranged. Lines flowing into the surface are counted as negative lines flowing out.
Note that there are eight lines flowing out of the surface enclosing the positive charge, negative eight lines flowing out of the surface enclosing the negative charge, and a total of zero (8-8) lines flowing out of the surface surrounding the surface enclosing a net charge of zero. (Remember that the picture shows two field lines pointing the wrong direction!)
