# Statement of Ohm’s Law

• The current flowing through metallic conductor is directly proportional to potential difference across it, provided that the temperature and other physical conditions remains same.
• If I is current passes through a conductor and V is potential difference across its terminal, according to ohm’s law
I α V (constant temperature)

OR

V α I

(V / I) = Constant

V = IR

Where R = Constant, it is called as resistance at given temperature

## Resistance

• It is a property of conductor to oppose the flow of current through it.
• The SI unit of resistance is ohm.
• One ohm = One volt / One ampere

According to ohm’s law

V = IR

I = V / R

Therefore, we can say that

I α V …… (1)

and I α (1 / R) …… (2)

• The current passes through conductor is directly proportional to potential difference across it.
• The current passes through conductor is inversely proportional to resistance of metallic conductor.

## Limitation of Ohm’s law

• The ohm’s law is not applicable for non – linear device such as semiconductor material.
• Not applicable for unilateral devices such as PN junction diodes and transistors.
• Th ohm’s law is not applicable for non – metallic conductors.

You may also like :

What is electric charge?

What is mobility?

Mobile charge carriers and immobile ions

Bohr atomic model