Chapter 28, Problem 32P

(III) Suppose the current in the coaxial cable of Problem 31, Fig. 28–42, is not uniformly distributed, but instead the current density j varies linearly with distance from the center: j₁ = C₁R for the inner conductor and j₂ = C₂R for the outer conductor. Each conductor still carries the same total current I₀, in opposite directions. Determine the magnetic field in terms of I₀, in the same four regions of space as in Problem 31.