OHM'S LAW

Ohm's Law: This law gives the relation between the potential difference V and the current I flowing through a conductor.

It may be stated as:

"For a given conductor the ratio of the steady direct potential difference V between its ends to the steady direct electric current I flowing through the conductor, is a constant, provided the physical conditions of the conductor , for example- temperature, etc., remain unchanged."

This Law, however, is also applicable to AC circuits.

It can be represented by

                       

or                    

or                    

or                    

or                    

where R is a constant for the conductor and is called its electrical resistance or resistance of the conductor

The quantities V, I and R measured in volts, amperes, and ohms respectively.

From the above relation of Ohm's law i.e., V = I R , it may be deduced that a conductor is said to offer a resistance of one ohm, when a unit potential difference (1 volt) applied across its ends, causes a unit current (1 ampere) to flow through it.