Hi, I was reading some text and came across this problem, the problem is also mentioned in this link from Wiki: http://en.wikipedia.org/wiki/Inductance#Self-inductance They said that it is because the 1/R now becomes infinite, this is what I'm confused about. From my understand, there would be some point where R=0 while taking the integration, but in the thick conductor case, isn't there also overlapping point that make R=0? how come these points doesn't make the integration infinite? what made a thick wire so different from a very thin wire? and what's the physical meaning of this phenomena? Thank you.