1. The problem statement, all variables and given/known data A solid conducting sphere of radius r1 has a total charge of +3Q. It is placed inside (and concentric with) a conducting spherical shell of inner radius r2 and outer radius r3. Find the electric field in these regions: r < r1 r1 < r < r2 r2 < r < r3 r > r3 2. Relevant equations E = F / q E = kq / R (for a point charge) 3. The attempt at a solution Because it's a conductor, I know that the electric field for r < r1 should be 0 (I also forgot the reasoning for this. I think it's because the charges are moving and somehow they cancel each other out?) I'm confused on the other parts, though. For r1 < r < r2, I said that the electric field is 3kQ/r because the electric field from the sphere could be felt from that point. For r2 < r < r3, I said that the electric field was 0 for the same reasoning as r < r1, and I'm not even sure if that makes sense. Finally, for r > r3, I said it was 3kQ / r.