1. The problem statement, all variables and given/known data In an RC circuit, should a graph of R vs. tau necessarily go through the origin? What does a non-zero intercept indicate? 2. Relevant equations 3. The attempt at a solution My graphs look like they go through the origin, and from the equation tau = RC, I would expect that when R is zero, tau is also necessarily zero. However, from the definition of tau as the time necessary for the charge on a capacitor to go from 0 to 63.2% of the max charge, it seems to me that tau can never actually be zero. Also, because the wires themselves have some degree of resistance, R seems like it would never actually be zero either. I'm not sure which idea to go with. Thanks for your help!