Ohm's law:
It states that the current(I) flowing through a conductor is directly proportional to the potential difference(V) across the conductor provided all physical conditions and temperature remains constanti.e. I∝V
∴ V=IR
Where R is the resistance of the conductor.
Alternative form of Ohm's Law:
It states that, the current density(J) through a conductor is proportional to the Electric Field(E) across it.
J=σE
Where σ is the conductivity of the conductor.