What is more accurate definition of Ohm's law and resistance? is it
This is doubt that developed in my mind during a class where professor derived power equation where he used second one for resistance in the derivation. I checked Wikipedia. They showed the first relation as accurate. Of course if the first relation is correct and resistance \$R\$ is constant, then we can use second relation. But what if resistance is not constant?
For a practical problem, suppose my voltage source is current dependent and is given by
Then how will you find resistance of given circuit at a given value of current \$I\$?