# Difference between Resistance and Resistivity

Resistance and resistivity are the major terms associated with the opposition in the flow of electric current in a circuit. The most significant difference between resistance and resistivity is that resistance is the measure of opposition offered by the material in the path of electric current, whereas resistivity is the property of material by virtue of which it opposes the electric current.

In this article, we have explained all the significant differences between the resistance and resistivity in detail. Also, we have added a short description of resistance and resistivity for the reference of reader.

## What is Resistance?

Electrical resistance is defined as the measure of opposition offered by the material of the conductor in the path of electric current (or electric charges or electrons). It is also known as electrical friction as it slows down the motion of electrons.

According to ohm's law, when a voltage is applied across a current, an electric current starts flowing through the conductor, and the ratio of voltage across and current through remains the constant provided the physical condition such as area, length, temperature, etc. of the conductor does not change, i.e.

$$\frac{V}{I}\:=\:\mathrm{Constant}$$

This constant is known as resistance of the given conductor. The resistance is denoted by 'R' and is measured in Ohms (Ω).

Also, for the given conductor, let

$$l\:=\:\mathrm{length\:in\:meters}$$ $$a\:=\:\mathrm{Area\:of\:cross\:section\:in\:m^2}$$

Then, the resistance can also be defined in terms of physical dimensions as

$$\mathrm{Resistannce},R\alpha\:\frac{l}{a}$$ $$\Rightarrow{R\:=\:\rho\frac{{l}}{a}}$$

Where, "ρ" is the resistivity of the conductor

## What is Resistivity?

The property of material by virtue of which it opposes the flow of electric current (or electric charge or electrons) is known as resistivity of the material. It is denoted by the Greek letter 'ρ'.

The resistivity depends upon the nature of the material of the conductor and temperature. The resistivity of a conductor having resistance R, length l and area of cross-section a, is given by,

$${\rho\:=\:R\frac{{a}}{l}}$$

The unit of resistivity is Ohm-meter (Ω-m). The resistivity of a conductor is independent of the physical dimensions of the conductor.

## Difference between Resistance and Resistivity

The major differences between resistance and resistivity of a conductor are highlighted in the following table −

Basis of DifferenceResistanceResistivity
DefinitionThe measure of opposition offered by a conductor in the flow of electric current is known as resistance.The property of material of a conductor by which it offers an opposition in the flow of current is called resistivity.
Alternate nameResistance is also known as electrical friction.Resistivity is also known as specific resistance.
DenotationResistance is denoted by symbol 'R'.Resistivity is denoted by a Greek letter rho 'ρ'.
FormulaResistance of a conductor of length 'l' m, cross-sectional area 'a' m2 and resistivity 'ρ' is given by, $${R\:=\:\frac{{\rho{l}}}{a}}$$Resistivity of material of a conductor is given by,$${\rho\:=\:\frac{{Ra}}{l}}$$
Unit of measurementThe SI unit of resistance is Ohm (Ω).The unit of resistivity is Ohm-meter (Ω-m).
DependencyResistance of a conductor depends upon the physical dimension of the conductor like length, area of cross-section and temperature.Resistivity of the material of conductor depends upon the nature of material and temperature. It is independent of the physical dimensions such as length and cross-sectional area.
ApplicationsResistance is the electrical quantity used for designing various devices such as heaters, electric kettles, sensors and various types of resistors, etc.Resistivity is the property of material which used in various applications such as quality control test, selection of right material for manufacturing a resistor for a specific use, etc.

## Conclusion

In this article, we have illustrated various differences between resistance and resistivity of the conductor. As we can see, there are several differences between resistance and resistivity, but both of them are the parameters defining the opposition in the flow of electric current.

Updated on: 04-Jul-2022

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