# Electric Field due to Solid Non-Conducting Cylinder

1. Feb 7, 2012

### thiefjack

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

Positive charge is distributed throughout a solid non-conducting cylinder of radius 'b ' and infinite length. The charge density increases with radius according to ρ = ${ρ}_{o}$(${r}{^2}/{b}{^2}$), where ${ρ}_{o}$ is a constant (evidently equal to the charge density at the surface of the cylinder).

Find the electric field intensity, E, as a function of radius, outside the cylinder.

2. Relevant equations

E = k${dq}/{r}^{2}$

3. The attempt at a solution

Not sure where to get started, actually. If we try to find the electric field intensity at a position outside the cylinder wouldn't it be dependent on how far out we're finding the electric field and not dependent on the radius?

Last edited: Feb 7, 2012
2. Feb 7, 2012

### Spinnor

This is a straight forward application of Gauss's Law. See example 1.4 which is similar to your problem.

http://www.chem.ox.ac.uk/teaching/Physics%20for%20CHemists/Electricity/Gauss.html [Broken]

http://research.physics.illinois.edu/PER/unit4.pdf [Broken]

Last edited by a moderator: May 5, 2017
3. Feb 13, 2012