Calculating Coaxial Cable Insulation Resistance for Radial Current Density

[yayovio10]

Homework Statement

Determine the insulation resistance in a coaxial cable of length L, with conductivity, as shown in Figure assume that the current density J is radial direction.

The Attempt at a Solution

so i was wondering if this approach is correct,

consider a sequence of cylindrical shells of radius r and thickness dr. Each shell has a resistance dR given by:

 

[rude man]

This has already been posted and responded to.
The method is correct this time (I seem to recall it changed from the last post).