Problem # 4 In a Coaxial Cable, a solid conductor with radius a is supported by insulating disks on the axis of a conducting tube with inner radius b and outer radius c as shown in Figure. The central conductor and tube carry equal currents I in opposite directions. The currents are distributed uniformly over the cross sections of each conductor. Derive an expression for the magnitude of the magnetic field (a) at points outside the central, solid conductor but inside the tube (a c) Repeat the Exercise for the case in which the current in the central, solid conductor is I1, the current in the tube is I2, and these currents are in the same direction rather than in opposite directions.

Problem # 4 In a Coaxial Cable, a solid conductor with radius a is supported by insulating disks on the axis of a conducting tube with inner radius b and outer radius c as shown in Figure. The central conductor and tube carry equal currents I in opposite directions. The currents are distributed uniformly over the cross sections of each conductor. Derive an expression for the magnitude of the magnetic field (a) at points outside the central, solid conductor but inside the tube (a c) Repeat the Exercise for the case in which the current in the central, solid conductor is I1, the current in the tube is I2, and these currents are in the same direction rather than in opposite directions.