Answer: A coaxial cable is made of a 0.1-in.-square inner conductor and a 0.5-in.-square

Chapter 12, Problem 7

(choose chapter or problem)

A coaxial cable is made of a 0.1-in.-square inner conductor and a 0.5-in.-square outer conductor. The potential at a point in the cross section of the cable is described by Laplaces equation. Suppose the inner conductor is kept at 0 volts and the outer conductor is kept at 110 volts. Find the potential between the two conductors by placing a grid with horizontal mesh spacing h = 0.1 in. and vertical mesh spacing k = 0.1 in. on the region D = {(x, y) | 0 x, y 0.5 }. Approximate the solution to Laplaces equation at each grid point, and use the two sets of boundary conditions to derive a linear system to be solved by the Gauss-Seidel method.