Problem: Coaxial Cable

A coaxial cable consists of an outer conductor and an inner conductor separated by an insulating plastic filler.  These two conductors usually carry equal currents in opposite directions.  You may have seen this type of configuration on  cable TV hookups as well as certain types of computer networks.  The above simulation shows the progression of the magnetic fields as many small wires are added to produce a coaxial configuration.

  1. Watch the magnetic fields change as the simulation first build the outer conductor followed by the inner conductor.  Explain why this type of cable might be preferable to household wiring or lamp cord which consists  two side-by-side wires carrying currents in opposite directions.
  2. Click drag to measure the field at any point.  Find the current passing through the inner conductor.