The picture shows an insulating sphere with a positive charge uniformly distributed throughout its volume. What is shown on the graph as the gaussian sphere inflates?

1. Electric flux through the gaussian sphere vs. r
2. Magnitude of the electric field at the surface of the gaussian sphere vs. r
3. Electric potential at the surface of the gaussian sphere vs. r
4. None of the above

The graph shows the electric flux through the gaussian sphere as a function of r. As the sphere inflates it encloses more and more charge until it encloses the whole sphere. After that the enclosed charge is constant so the electric flux is constant.