Question

Deduce the relation connectimg current density and conductivity

Answer 1

Answer:

As we have already derived and discussed the Ohm’s law. Let us derive and discuss the point form of Ohm’s law which is basically the relation between current density (J), conductivity (σ) and electric field (E).

As current  is related with drift velocity by relation

I=n Aevd

I = n Ae(eE/m)              ( because vd=eE/m)

I   = nAe2E/m

Or                  I/A=ne2 E/m                            (1)

As current density is given by J=I/A (Refer article of Current Density, Conductance and Electrical Conductivity)

and  resistivity is given by  ρ=m/ne2t

By putting above values of J and ρ equation (1),