What is the difference between Resistance and Resistivity?
What is the difference between Resistance and Resistivity? As a physics student, you probably must have come across these two terms. Are they one and the same thing? Read on to find out if there exists any difference between them.
Resistance and Resistivity
Resistance and resistivity are related to each other but they are not the same thing.
Resistance is the measure of the opposition to the flow of current through a conductor. It is measured in ohms (Ω) and depends on the material, its length, cross-sectional area, and temperature. The resistance of a material is proportional to its length and inversely proportional to its cross-sectional area. The longer the material, the greater the resistance, and the larger the cross-sectional area, the lower the resistance.
On the other hand, Resistivity is a measure of the material’s intrinsic property to resist the flow of current through it. It is the resistance of a material of unit length and unit cross-sectional area. Resistivity is measured in ohm-meters (Ω·m) and depends only on the material and temperature. Resistivity is a fundamental property of a material, and it is used to calculate the resistance of a conductor of a particular size and shape.
In summary, resistance is a property of a conductor, while resistivity is a property of a material. Resistance depends on the dimensions of the conductor, while resistivity depends on the material properties.
Their key differences
|The electrical resistance of an object is a measure of its opposition to the flow of electric current.||Resistivity is the characteristic property of the material by which it resists the amount of current through it.|
|It depends upon the|
area of cross-section
and nature of the material of the given material,
and physical conditions like temperature
|It only depends upon the|
nature of the material
and physical conditions like temperature.
|Its SI unit is the ohm (Ω)||Its SI unit is an ohm meter. (Ω-m)|
|It is denoted by R.||It is denoted by ρ (rho)|
|The formula for Resistance is|
R = V/I,
or R = ρ(L/A)
where V = Voltage, I = Current, ρ = Resistivity
|The formula for Resistivity is |
ρ = (R×A)/L
where R = Resistance, L= Length, A = Cross-sectional area
|Resistance depends on the dimensions of the material, like length, area of cross-section|
Resistivity is independent of the dimensions of material