Problem Set 4

Due Friday, October 9, by 2 pm in PHY 142 homework locker

Problem 1 [10 points]
Consider a sphere of radius a, containing a uniform charge density ρ such that the total charge on the sphere is Q. Find the electrostatic energy U stored up in this configuration via the following two methods:
a) U = (1/2)∫ dV ρφ
b) U = (1/8π)∫ dV |E|²
Both methods should give you the same result. Compare to your result from Problem Set 2, problem 1 (Purcell 1.9).
Problem 2 [5 points]
Purcell problem 2.15
Problem 3 [5 points]
Purcell problem 2.16
Problem 4 [10 points]
Purcell problem 2.20
Problem 5 [10 points]
Purcell problem 2.28
Problem 6 [10 points]
Purcell problem 2.31