1. The problem statement, all variables and given/known data Okay this is a simple first year physics question, but I couldn't find anything about it online. Using the simple equation for electric field/potential due to a point charge, what's the electric potential/field at the coordinates of the point charge itself? 2. Relevant equations 3. The attempt at a solution I'm tempted take limits as r approaches 0, but that seems to imply it approaches infinity which appears absurd. Either that or it's undefined. Anyone?