Chapter 6, Problem 6.19P

Construct a curvilinear- square map of the potential field between two parallel circular cylinders, one of 4 cm radius inside another of 8 cm radius. The two axes are displaced by 2.5 cm. These dimensions are suitable for the drawing. As a check on the accuracy, compute the capacitance per meter from the sketch and from the exact expression:

$C=\frac{2\tau \epsilon }{{\cosh }^{-1}[\left(a^2+b^2-D^2\right)/\left(2ab\right)]}$

Where a and b are the conductor radii and D is the axis sepatation.