A coaxial cable consists of a center conductor and an outer cylindrical conductor having an insulating material in between. The current can flow via the center conductor to some device and then return to the source through the outer conductor.
i) Determine the magnetic field outside the cable when a current of 2A is flowing to and from the device?
ii) Explain how would the magnetic field be different when the two conductors were parallel conductors as in a lamp cord?