Can two points on a superconductor have a potential difference?
Bare with me if this is stupid (I've been away from my electrical engineering roots for really long time now). I was wondering if the medium affects the potential difference between any two points. When we say there's a potential difference - it's relative. But when the medium is super-conducting - can the potential difference still exist?
I read that even the superconductors offer some, but negligible, resistance to the flow of electrons. But under ideal superconducting situations, the two points under consideration would be one and the same (theoretically).
What I want to know does the medium influence the PD between two points in electrical circuits.