The current flowing through a conductor is directly proportional to the potential difference across the ends of the conductor and inversely proportional to its resistance.

            If V is the potential difference across the ends of a conductor, R is its resistance and I is the current passing through it then as per the Ohm’s law

I α V/R

or I = V/R

or V = IR

Where I is the current in Amperes, V potential difference is volts and R is the resistance of the conductor in ohms.

Limitations:

1.      It can not be applied to the circuits containing transistors.

2.      It is not applicable for the circuits containing non linear such as   electric arc and powdered carbon etc.