Question

Define resistivity and write its si unit and the mathematical expression for a given substance how does it differ from resistance

Answer 1

Electrical resistivity or specific resistance

is a physical attribute of a material that defines how much it opposes the flow of electric current through itself.Resistance of a conducting material of unit length and having unit area of cross section.It depends upon on the nature of the material. Its SI unit is Ohm meter.So when we have a thick wire the resistance decreases and when we have a thin wire the resistance increases. so we can say that resistance is inversely proportional to the cross sectional area of the conductor.

I hope this answers your question !

Answer 2

Answer:

Explanation:

Resistivity can be defined as the resistance of a conducting material per unit length with unit area of cross section. 

So it SI unit will be

ρ= RA / l

The resistivity of a conducting material depends upon;

nature of material

relaxation time of free electrons

temperature difference

SI unit of resisitivity is OHM/m