# Electric Field near a finite conducting stick

1. Oct 2, 2011

### Bassalisk

So this should probably go into math's section, but I feel you guys can give me the answer too, since this comes from an EE course(Theory of electromagnetic fields)

[PLAIN]http://pokit.org/get/2f3e7eef6b38bc75f0023b94976a2997.jpg(1) [Broken]
[PLAIN]http://pokit.org/get/fc8658090d67ae0fafe79970021d1518.jpg(2) [Broken]
[PLAIN]http://pokit.org/get/96df286729f6eafc76fd601b22bd66c7.jpg(3) [Broken]
[PLAIN]http://pokit.org/get/10ffe4ec16d38b03ef9cdafe86149e16.jpg(4) [Broken]

dQ=Q'*dz'

So basically question is this:

How did he get that integral solved? This actually not homework this is a solved case, I just don't understand how did he get figures 4 out of 3. What are the boundaries of this integral? How did he solve this?

Last edited by a moderator: May 5, 2017
2. Oct 2, 2011

### Winzer

Boundaries of the integral: Think about it, what are we integrating over? The rod right? The rod is of length L, but is centered over the mid point of the rod. Do you see that we would integrate from -L/2 to L/2?

So you got your bounds. Now separate the integral into its vector components.
The first integral(a_r component) you can solve with an integral table. Second one you can solve after two substitutions.

3. Oct 2, 2011

### Bassalisk

Yea was thinking of those, but when I saw a vector in my integral I freaked out.

Thank you. I will try this.