 # Ohm’s Law

In 1827 a German physicist Georg Simon Ohm found out the relationship between the current and potential difference which is known as Ohm’s Law.

## Ohm’s Law

The potential difference (V) across the end of a given metalic wire in an electric circuit is directly porpotional to the current flowing through it provided its temperature remains the same. this is called Ohm’s Law.

potential difference  ∝  electric current                                                                            V  ∝      I

The resistance of a conductor isthe ratio of the flowing current. Its  S.I. unit is Ohm. Represented by the Greek letter  Ω

if                             V ∝ I Potential difference   = Resistance X Current

Resistance = potential difference / Current

Define 1 Ohm.

If the potential difference across the two ends of a conductor is volt and current through it is 1 A. Then the resistance R , of the conductor is 1 Ohm

1 Ohm = 1 volt / 1 ampere

The current through a resistor is inversely porpotional to its resistance.

What is variable resistance?

A component used to regulate current without changing the voltage source is called variable resistance.

Which device is used to change resistance in the circuit?

A device called rheostat is often used to change the resistance in the circuit.

The electron are not completely free to move within a conductor. They are restrained by the attraction of the atoms among which they move.

Motion of electron through a conductor is resistance is a good conductor.

A componnt of a given size that offer a low resistance is a good conductor.

A conductor having some appereiable resistance is called a resistor.

A component of identical e tat offer a higher resistance is a poor conductor.