1. The problem statement, all variables and given/known data Find the angular frequency, w, at which the displacement current is equal to the free current in a conductor. 2. Relevant equations jd(dislacement current) = ee_0(dE/dt) where e = permiability of material and e_0 is the permitivity of free space E=electric field also j=sE (s=constant of proportionality) j = free current 3. The attempt at a solution from the question ee_0(dE/dt) = sE assuming that E=E0exp(i(wt-kz)) (plane wave) so therefore dE/dt = iwE ee_0*i*w*E=sE or (ee_0*i*w)(-ee_0*i*w)=s^2 (taking complex conjugate) or w=(s^2/(ee_0)^2)^1/2 =s/(ee_0) so the frequecy at which displacement current equals free current is s/(ee_0). Is this derivation correct.