State Ohm's law

State Ohm' law and deduce it from the knowledge of drift velocity of free electrons in a conductor carrying current.

Resistance Ohm's law || Resistivity

Explain the Ohm's law.

In which one of the following cases Ohm's law is not vaild?

If V is the potential difference between the ends of conductor and l is the current through it, then ohm's law states that

Assertion: Ohm's law is not valid if current depends on voltage non-linearly. Reason: Ohm's law is a fundamental law of nature.