In 1828,
** George
Simon Ohm**, a German physicist, found that for many substances, the electrical current
I flowing through them is proportional to the voltage V across their ends.

The empirical relationship

** V µ
I**

is called Ohm's Law. The constant of proportionality, called the resistance and given the symbol R, is independent of V or I, but depends only on the substances and its shape and size. Thus Ohm's Law is

**V = R * I**

**Unit
of Resistance:-**

Volt per ampere OR Ohm ( W )

**
****Click here for practical
Example**