I encountered a interesting problem. It first invokes the fact that between two points, potential difference is independent of the path between them. Then, it asks you to apply it for a wire carrying constant current I. Path 1: Along the wire. Path 2: Going in a curved path outside the wire. The thing is, a non zero field is needed outside the wire to evaluate (E . dr). It hints of a surface charge density on the wire. But, I am not able to correlate it with our day to day observation or find its distribution mathematically. The two paths


closed as unclear what you're asking by Kyle Oman, sammy gerbil, Prahar, ACuriousMind Jun 4 '18 at 17:06

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  • $\begingroup$ The scenario you've described is clear enough, but what exactly are you asking? How to find the surface charge on a current carrying wire? Something else? $\endgroup$ – Kyle Oman Jun 4 '18 at 7:58
  • $\begingroup$ Yes, I would like to know its distribution. I am even confused as to how field lines are starting and ending on the same surface. $\endgroup$ – Sarthak Rout Jun 4 '18 at 7:59
  • $\begingroup$ @Sarthak Rout Why do you think that field lines start and end on the same surface ? $\endgroup$ – Abhinav Dhawan Jun 4 '18 at 8:48
  • $\begingroup$ I am taking a path, a curved one which starts on point A on the wire and ends on another point B in the wire. From A, I leave the surface, kinda fly above it and then land on point A. So, the surface, (can assume cylindrical), is same. I will be adding a pic. $\endgroup$ – Sarthak Rout Jun 4 '18 at 9:25
  • $\begingroup$ There is an electric field outside a wire. physics.stackexchange.com/questions/61884/… $\endgroup$ – Farcher Jun 4 '18 at 9:53