# Determining Electric field of Spherical charge distribution

1. Sep 16, 2004

### JasonZ

Hey, this is from "Foundations of Electromagnetic Theory" by Reitz, et al. Problem 2-15.

I have had a really hard time trying to learn from this book as there are no examples to apply the equations they prove throughout the chapters. Anyhow, I don't really have anything down for this problem, which is as follows:

A spherical charge distribution has a volume charge density that is a function only of r, the distance from the center of the distribution. In other words, $$\rho = \rho (r)$$. If $$\rho (r)$$ is as given below, determine the electric field as a function of r. Integrate the result to obtain an expression for the electrostatic potential $$\phi (r)$$, subject to the restriction that $$\phi (\infty) = 0$$.

(a) $$\rho = \frac {A}{r}$$ with A a constant for $$0 \leq r \leq R; \rho = 0$$ for $$r > R$$.

I assume this is a Guass law problem, I just don't understand how to solve the right hand integral, supposing it is indeed: $$\int \rho dv$$

Can anyone help me, I am quite stuck.

-Jason

Last edited: Sep 16, 2004