Question

Define the term resistivity and write its unit:

Answer 1

Hint:Resistance is characterized as the property of the conductor which opposes the progression of electric flow. It is likewise characterized as the proportion of the voltage applied to the current flow moving through it. It is used to compare various materials for their ability to conduct electricity.

Complete step by step solution:
The term resistivity is defined as the resistance offered by a conductor of length \[1m\] and area of a cross-section \[1{m^2}\]. It is the measure of the resistance of a given size of a specific material to electrical conduction.
Resistivity is defined as the electrical resistance of the conductor of unit cross-sectional area and unit length. We can usually describe how well a material is carrying current. It enables a comparison of how different materials allow or resist current flow. It describes the material’s property of how difficult it is for electric current to flow through that material.
Therefore we can say that materials with high resistivity are known as insulators and materials with low resistivity are known as conductors.
Its unit is \[ohm - m\] \[(\Omega m)\].

Additional Information:
Resistivity is commonly described by the Greek letter \[\rho \].
The formula for the resistivity is given as,
\[\rho {\text{ }} = {\text{ }}\dfrac{{\left( {R \times A} \right)}}{L}\]\[(\Omega m)\]
Here, \[R\] is the resistance of the material
\[A\] is the cross-sectional area
\[L\] is the length
The values of resistivity of conductor and insulator are as follows
For the good conductor, resistivity ranges from \[1.77{\text{ }} \times {\text{ }}{10^ - }^8\]\[(\Omega m)\]to\[1.77{\text{ }} \times {\text{ }}{10^ - }^6\]\[(\Omega m)\].
For insulators, resistivity ranges from \[{10^1}^2\] to \[{10^2}^0\]\[(\Omega m)\]

Note:
The difference between resistance and resistivity is that resistance is the physical property of the substance because of which it opposes the flow of current, whereas the physical property of a substance which is having particular dimensions.
Resistance is directly proportional to length and temperature while it is inversely proportional to the cross-sectional area. Whereas, resistivity is only proportional to the nature and temperature of the particular material.