1. The problem statement, all variables and given/known data This is a question from an old exam. The answer I have is marked wrong but I do not know why. A conducting sphere of radius a is at potential V and sits at the center of a conducting spherical shell so large that it can be considered infinite and whose potential is zero. The whole system sits at a high temperature T, so that electrons emitted from the conductors form a dilute gas. Assume the density of these electrons is very low so that their mutal interaction can be neglected. (a) Calculate the potential energy for an electron of charge -|e| as a function of radius r from the center of the system. (b) In thermal equilibrium, the electrons form a gas of variable density Using the results from part (a) find the dependence of the charge density on the radial distance r. 3. The attempt at a solution (a) The answer I have is (1/4πε0)(V/a-V/r) Is this correct? (b) I have no idea what the questioner is asking for.