I add something: the current distribution in a complex conductor is not a simple series-parallel relationship, so it is difficult to calculate the current distribution. Whether it should have a premise that the solution is the uniform isotropic bulk material, in this case，to calculate the resistance under DC.
My fellower abvise me to make a clear knowledge system of resistors, thus I have to find more info about resistors, toady I read an article about it, its has many theories and some examples, but it not enough. Although it has theories to introduce resistors, the examples to support these theories are rare. So is there anyone can give some reference materials like this https://www.kynix.com/Blog/316.html, be specific, what's more, giving examples to make me understand well.
Thank you in advance.