1. The problem statement, all variables and given/known data A flat ring (inner radius R_0, outer radius 4R_0) is uniformly charged. In terms of the total charge Q, determine the electric field on the axis at points a) 0.25R_0 b) 75R_0 from the center of the ring. [Hint: The ring can be replaced with two oppositely charged superposed disks.] 2. Relevant equations Gauss's Law Coulomb's Law 3. The attempt at a solution I'm okay with part b. The ring will be like a point charge, so using Coulomb's law would lead to the correct result. But I'm not even sure what I'm supposed to imagine for part a. I guessed that it would be zero eventually because there cannot be electrical field inside a conductor, but didn't do anything like hint says I should.