Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points provided, physical conditions (such as the temperature of the conductor) remain the same.
Ohm’s law formula is written as;
V ∝ I
Therefore, V = RI
where R is a constant called resistance. R depends on the dimensions of the conductor and also on the material of the conductor. Its SI unit is Ohm (Ω).
A V-I graph is shown below: