Question

what is a microscopic physical quantity using as definition the concept the resistence of the material from which the wire is made?

Answer 1

Resistance is defined as,

Where l is length of wire , A is area of cross-section of wire , rho is resistivity of wire.

Now , rho is determined by microscopic property of wire.

pho is reciprocal of conductivity. Conductivity is represented as sigma.

n = density of electron

e = charge of electron

= mass of electron

d = mean free path

= root mean square speed of electron

These are above microscopic quantity on which resistance of wire depends .