what is Definition of resistance ? MKS SI unit symbol formula , examples all about here you get information : Resistance is the property of any material which opposes the flow of current through the material.
The unit of resistance is ohm and this is denoted by a greek symbol Ω omega.
The resistance is written by capital letter R.
example : if someone says write resistance of any material 50 ohm then we will write this like this R = 5Ω .
Formula to calculate resistance of any material
R = V/I
here V = voltage or potential difference
I = electric current
when V = 1 volt and I = 1 ampere then R = 1 ohm
so we can say that between two points having 1 volt potential difference , flowing 1 ampere current between these points then the resistance between these two points will be 1 ohm.
The insulators materials do not allow flow of current through them so we can say that they have high resistance value . that high resistance value resists the flow of current through them.
Because insulating material containing high resistance value so this is measured in kilo ohm or mega ohm.
The materials which having low value of resistance is measured in milli ohm or micro ohms.
When the applied voltage is held constant then the flow of current through the material is inversely proportional to the resistance of the material .
I ∝ 1/R
If a material having high value of resistance than the flowing current through this material will be low .
If a material A having double current in comparison to another material B.
It means the resistance of material A will be half in comparison to the material B.