(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

An electric field in the region r > a is given by

E,r = 2*A*cos(theda)/r^3

E,theda = A*sin(theda)/r^3

E,phi = 0

A = constant

Find the volume charge density in this region.

E,r and E,theda and E,phi are the components of E in the r, theda, and phi directions, respectively.

2. Relevant equations

div E = p/eo

p = volume charge density

E = electric field

eo = permittivity of free space

div is divergence

3. The attempt at a solution

Well, I started by calculating the divergence of E in spherical coordinates and got that it is equal to zero. So p/eo = 0 ==> p = 0?

This isn't correct, so I'm confused on what I need to do. Does r > a have some significance? It gives no information about what sort of volume this is or what a is, and there are no diagrams or anything.

Thanks for any help.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Gauss' Law question

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