Question

State microscopic form of ohm's law with answers

Answer 1

Answer:

Explanation:

The microscopic form of Ohm's law is J =σ E,

where σ is the electrical conductivity, E the electric field and J the current density .

This form of Ohm's law operates on a microscopic level relating the current density J to the conductivity σ and the electric field E.

Derivation:

We know that the current I = A ne(Vd) ......(i)

as we know that drift velocity Vd = eE/m ( t )        

where t is the average relaxation time , m is the mass of charged particle.

I = nAe { eE/m (t) }

=>  I/A = ne²Et/m

=>  J = 1/ρ E                      ( resistivity ρ = m/ne²r )

=>  1/ρ =  σ

=>  J = σE