Resistivity of Conductor-
Before you go through this article, make sure that you have gone through the previous article on Resistance of Conductor.
The resistance of a conductor of length L and area of cross-section A is given by-
If L = 1 unit and A = 1 unit, then R = ρ
Thus, resistivity of material of a conductor may be defined as-
|The resistivity of a material may be defined as the resistance of that material having unit length and unit area of cross-section.|
|It is the resistance offered by the unit cube of that material.|
It may be noted that-
- The resistivity is a property of material of the conductor.
- It is also called as specific resistance.
SI Unit of Resistivity-
|The SI unit of resistivity is ohm meter (Ω m).|
The SI unit of resistivity may be derived as-
Factors Affecting The Resistivity-
The resistivity of material of a conductor depends upon the following factors-
1. Nature of Material-
- The resistivity of a conductor depends upon the nature of its material.
- The resistivity of a conductor also depends on its temperature.
- The resistivity of a conductor increases with the increase in its temperature.
Very Important Note
The resistivity of a conductor is independent of the dimensions of the conductor.
In other words,
The resistivity of a conductor does not depend upon its length and area of cross-section.
At a constant temperature, it depends only on the nature of material of the conductor.
Conductivity of Conductor-
|The reciprocal of the resistivity of a material is called its conductivity.|
- More is the resistivity of a conductor, lesser is its conductivity and vice-versa.
- So, conductivity of a conductor is defined as reciprocal of resistivity of the conductor.
- It is denoted by σ.
The SI unit of conductivity is ohm-1 m-1.
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