2.16  

Figure 2.26

A long coaxial cable (Fig 2.26) carries a uniform volume charge density r on the inner cylinder (radius a), and a uniform surface charge on the outer cylindrical shell (radius b). This surface charge is negative and is of just the right magnitude that the cable as a whole is electrically neutral. Find the electric field in each of the three regions: (i) inside the inner cylinder (s < a), (ii) between the cylinders ( a < s < b), (iii) outside the cable (s > b). Plot |E| as a function of s.