Difference between Resistivity and conductivity
The basic concept behind the electrical resistivity is that when we give electricity to the material then electrons are start flowing through the material but it comes into contact with the atoms in the material and due to their collision resistivity of the material increase. Electrical resistivity and conductivity both are very interesting and important properties of material. The resistivity and conductivity is different for different materials. Both resistivity and conductivity are inversely proportional to each other. When one property is low another is high and vice versa. Electrical resistivity is a measure of a resistance in the particular material of given size which we are using for electrical conduction, or we can say it as specific electrical resistivity. Electrical conductivity is a measure of conduction of electric current of a material which we are using for electrical conduction, or we can say it as specific conductivity. The difference between them is as follows.
Resistivity or Specific resistance.
1) The property of material which describes the ability of opposition to flow of electron in conductor is known resistivity.
2) We know that, resistance of conductor increases with increase in length and decreases with increase in area of cross-section, hence the resistivity can be obtained as,
Here ‘ρ’ is constant of proportionality, known as resistivity or specific resistance.
3) The formula for resistivity can be written as,
∴ ρ = (R A)/L
4) From above formula Resistivity can be defined as, Electrical resistance of a conductor of unit cross-sectional area and unit length.
5) SI unit of resistivity is ohm-meter (Ω.m)
6) Resistivity of material is always constant irrespective its length, area of cross-section and shape.
7) Eg. If a copper wire of length 100 cm, and area of cross-section of 1.2 cm2 has resistance of 150 ohm then the resistivity of copper is
Conductivity
1) The property of material which describes the ability of flow of electron in conductor is known conductivity.
2) Conductivity is reciprocal of resistivity.
∴ σ = 1/ρ
But, ρ = (R A)/L
∴ σ = L/RA
3) SI unit of conductivity is 1/(Ω-m) or it is also called as siemen (S)
4) Higher is the conductivity, lower is the resistivity.
5) Conductivity of substance is constant and independent of length, area of cross-section etc.
6) Eg. If a copper wire of length 100 cm, and area of cross-section of 1.2 cm2 has resistance of 150 ohm then the conductivity of copper is