1. The problem statement, all variables and given/known data A ring of radius R lies in the x-y plane with the center at the coordinate origin. The ring is uniformly charged with with a uniform charge density +λ. a) Charge +q is brought along the z-axis from -∞ to the center of the ring. What is the increase in total potential energy of the system, ΔUa? 2. Relevant equations ΔV=-∫E⋅dr W=qΔV 3. The attempt at a solution The professor mentioned that the solution is so simple that it doesn't even require us to integrate the electric field in order to find the solution. I'm just confused as to what exactly the electric potential would be at the center of the charged ring. I doubt it'd be zero or ∞, but I'm at a loss as to what else it could be. Any hints to point me in the right direction would be greatly appreciated. Thanks.