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.
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.