question_answer 44)

  A long straight cable of length  is placed symmetrically along z-axis and has radius a («). The cable consists of a thin wire and a co-axial conducting tube. An alternating current  (t) = sin  flows down the central thin wire and returns along the co-axial conducting tube. The induced electric field at a distance s from the wire inside the cable is  (i) Calculate the displacement current density inside the cable. (ii) Integrate the displacement current density across the cross-section of the cable to find the total displacement current . (iii) Compare the conduction current  with the displacement current

Answer:

                  (i) Given, the induced electric field at a distance r from the wire inside the cable is Displacement current density. (ii) (iii) The displacement current, Where