# Ohms Law Lecture Notes

This law gives relationship between the potential difference (V), the current (I) and the resistance (R) of a d.c. circuit Dr. Ohm in 1827 discovered

a law called Ohm’s Law. It states, Ohm’s Law: The current flowing through the electric circuit is directly proportional to the potential difference across the. circuit and inversely proportional to the resistance of the circuit, provided the temperature remains constant.

Mathematically, V α I

V = IR

I = V/R

Where I is the current flowing in amperes, the V is the voltage applied and R is the resistance of the conductor

**Limitations of Ohm’s Law**

The limitations of the Ohm’s law arc,

1) It is not applicable to the nonlinear devices such as diodes, zener diodes, voltage regulators etc.

2) It does not hold good for non-metallic conductors such as silicon carbide. The law for such conductors is given by,

3) V = k Im where k, m are constants.