1. The problem statement, all variables and given/known data This is more of a general question, but a simple example would be find the force on a test charge q at the center of a ring of charge with a total charge Q and a charge distribution given as λ(θ) =ksin(θ) where θ is measured clockwise with respect to the positive x-axis. The ring has radius R. 2. Relevant equations Coulomb's Law for continuous charge distributions. 3. The attempt at a solution Problems like this that I've seen often involve non-conducting materials (or it's not specified). My question is, what happens if we have a conducting material? It's not clear if you could set up the integration the same way or not. In a conductor the field "inside' is zero because the charges are free to move and will naturally arrange themselves' in order to reach the lowest potential. All charge should be on the surface, and so there is no charge density inside the material. But I think I can reconcile this with the given charge density since it's linear, so I think we can say linearly there is a charge density.