1- simple conceptual problem, suitable as easy exam problem

2- practice with flux concept, okay as part of a multi-part conceptual exam problem, low difficulty if you understand electric flux … which is why it is here as practice and as item to promote discussion

3- difficult if given on exam, easy to execute but conceptually hard to visualize

4- perfect conceptual exam problem, ties what we are doing into something quite practical, moderate difficulty, requires a little synthesis

5- this is a moderate difficulty cylindrical Gauss’s Law problem, there are no hidden tricks, but like all Gauss’s Law problems, it is hard until you have the hang of them, appropriate for an exam

6- this is a moderate difficulty spherical Gauss’s Law problem, there are no hidden tricks, but like all Gauss’s Law problems, it is hard until you have the hang of them, appropriate for an exam