1. The problem statement, all variables and given/known data A conducting spherical shell that has zero net charge has an inner radius R1 and an outer radius R2. A postive point charge q is placed at the center of the cell. The 1st part was to find the electric fields at the 3 diff places. The part I need help on is where we have to find the charge density on inner surface r=R1 and outer surface r=R2. what I have a question about is. The signs would be opposite for inner and outer. Is the one entering (inner surface) negative and the one leaving (outer surface) positive? If so, why is it like that?