Two very long hollow conducting cylindrical shells are situated along the x-axis. The shells are concentric and have negligible thickness. The inner shell has a radius a and a linear charge density +lambda, while the outer shell has a radius b and a linear charge density -lambda. Take the zero of electrostatic potential to be at r = 0. The coordinate r measures the distance from the common axis of the two cylinders in a region far from either end.
a) Determine the electrostatic potential V(r) for all values of r
b) Sketch V(r) vs. r for all r
c) Determine the potential difference DeltaV between r=a and r=b
d) If a positive charge +q is released from rest at r=a, what will be its kinetic energy when it reaches the outer cylinder at r=b.
The Attempt at a Solution
a) at r=a
b) as the radius increases the potential goes down. It starts at some positive y value and ends at some negative y value.