Question

The resistivity of a substance depends upon
(A) Length
(B) Area of cross section
(C) Thickness
(D) Temperature

Answer 1

Electrical resistivity is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. We will check its dependency with the help of formula.

Complete step by step answer:
At high temperatures, the resistance of some materials increases with temperature.
$\rho=\rho_{0}(1+T-T_0)$
The resistivity of a material depends on its nature and the temperature of the conductor, but not on its shape and size. The SI unit of electrical resistivity is the ohm-meter.
Hence resistivity is dependent on the temperature.
Therefore option D is a correct option.

Additional information: We know that resistance and resistivity are different from each other. Electrical resistance is the measure of current flow in an electrical circuit in opposition, it is measured by ohms. Ohms are named after Georg Simon Ohm who is a german physicist who learnt the relationship between voltage, current and resistance. Whereas Resistivity is a measure of the resistance of a given size of material to electrical conduction. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter ρ. Resistivity is the microscopic property and resistance is the macroscopic property. Resistivity is a property of the material, resistance depends on the size and shape.

Note: Remember that resistivity describes how many conducting particles there are per unit volume, how much charge they carry and how fast they move in an electric field while resistance describes the relationship between current and potential (voltage) in a circuit. It depends on resistivity but also on the length and cross sectional area of the material in question (so it depends on the total number of electrons and how long of a distance they need to traverse).