| |
 |
|
|
Science Forum Index » Physics - Electromagnetic Forum » Gauss's law
Page 1 of 1
|
| Author |
Message |
| Guest |
 Posted: Sun Jun 24, 2007 11:35 am |
|
|
|
|
Given E=a_r*(20/r^2) mV/m in free space, find rho_v (the volume charge
density) at the point (3,-4,1) cm
The answer is supposed to be -1.42 nC/m^3. I have tried Gauss's law
both in integral and differential form, but I do not get the correct
answer so I would really appreciate all help I can get. |
|
|
| Back to top |
|
| John C. Polasek |
| Posted: Wed Jun 27, 2007 9:24 am |
|
|
|
Guest
|
On Sun, 24 Jun 2007 09:35:48 -0700, Vattenkannan@gmail.com wrote:
Quote: Given E=a_r*(20/r^2) mV/m in free space, find rho_v (the volume charge
density) at the point (3,-4,1) cm
The answer is supposed to be -1.42 nC/m^3. I have tried Gauss's law
both in integral and differential form, but I do not get the correct
answer so I would really appreciate all help I can get.
You should explain your terms ar and mV is megaV or milliV?
This should work, using the SI divergence equation del dot D = rho:
Find r from 3, -4,1.
E = k/r^2
D = eps0*k/r^2
del dot D = rho (P) = dD/dr
rho = -2*(eps0*k*)/r^3
Ignore the negative sign.
John Polasek |
|
|
| Back to top |
|
| |
|
Page 1 of 1
All times are GMT - 5 Hours
The time now is Fri Oct 10, 2008 8:31 pm
|
|