Ohm's law

Generally, for a metallic conductor has a constant resistance R when other physical conditions remain same. For a metallic conductor the current passing through conductor will be directly proportional to the potential difference V applied across its ends. George Simon Ohm gave the relationship between V and i, which is called ohm's law.
Ohm's law is just a empirical relationship. It is not a fundamental physical principle and does not specify any general property of matter. For electrolytes, another essential condition required for application of Ohm's law is that the physical state must remain the same. Ohm's law is valid only for metallic conductors in which V/i has a constant value irrespective of the magnitudes of V and i