Question

Define the term resistivity and write its
S . I unit & Derive the expression for
D resistance (ii) the resistivity of a
conductor in terms of number density of
free elections and relaxation time.​

Answer 1

Answer: resistivity is the resistance offered by a current carrying conductor of lenght 1m and area of cross section 1m2 when the current flows perpendicular to opposite face

R$\alpha$ l ×1/A

R=Pl/A

second qustn dont know sorry

Explanation:

Answer 2

Answer:

The SI unit of resistance is Ohm's

It is the interruption in the path of electric current which slows down the flow and produces heat.