Define electrical resistivity. Write its unit.

Hint: It is the property of resistance. First we will discuss the electrical resistivity then we will discuss the electrical resistivity of material. And, finally we will write the S.I unit and also discuss the formulae.

Complete answer:
Electrical resistivity is a property unique to every material, which is essential to understand before creating and designing electrical and electronic systems. Information on how materials differ in resistivity gives data to choosing proper materials utilized for building engines, electrical circuits, dielectrics, resistive warming, and superconducting applications.

Now, the question arises here that what is Electrical Resistivity of a particular material. So, Electrical resistivity, represented by the Greek letter $\rho $ (\ rho), is a measure of the resistance of a specific material of a given size, to the electrical current conduction that flows through it. It is likewise referred to as the particular electrical obstruction or volume resistivity. The SI unit of electrical resistivity is expressed in ohm-metres $(\Omega m)$ .

It is also found in units of $(\mu \Omega cm)$ . Insulators have high estimations of electrical resistivity in the range of ${10^{10}}\Omega m$ or more, whereas metal conductors have very small resistivity values in the range of ${10^{ - 8}}\Omega m$ .The electrical resistivity $\rho $ of a solid object is determined by passing an electric flow through an example and afterward estimating the resultant voltage drop over a specific length. It is communicated by the connection between the electrical field inside the material and the streaming electric flow.

Note:Resistivity and resistance must not be confused with each other. Resistivity is a material property with a natural worth simply like warm conductivity, while obstruction is affected by the shape, calculation, and resistivity.