PDA

View Full Version : Potential Difference b/t 2 points


rjnara
Jul13-06, 09:04 AM
Ok, I've got a problem:

The electric field in a region of space has the components Ey = Ez = 0 and Ex = (3.91 N/C)x. Point A is on the y axis at y = 2.83 m, and point B is on the x axis at x = 3.97 m. What is the potential difference VB - VA?

I have tried integrating E (wrt x) * x from x=0..3.97 . I keep getting 81.5506, and its not the right answer. Anyhelp would be appreciated

neutrino
Jul13-06, 09:22 AM
The p.d between A and B is -\int_{A}^{B}\vec{E}.d\vec{l}. In your problem this reduces to -\int_{0}^{3.97}E_xdx. Can you do it from here?

Andrew Mason
Jul13-06, 03:49 PM
Ok, I've got a problem:

The electric field in a region of space has the components Ey = Ez = 0 and Ex = (3.91 N/C)x. Point A is on the y axis at y = 2.83 m, and point B is on the x axis at x = 3.97 m. What is the potential difference VB - VA?

I have tried integrating E (wrt x) * x from x=0..3.97 . I keep getting 81.5506, and its not the right answer. Anyhelp would be appreciatedPerhaps you could show how you are doing the integration. I am not sure about your expression for E_x. Is the field \vec{E} = 3.91\hat{x} N/C (ie. constant field of 3. 91 N/C in the x direction) or is it: \vec{E} = 3.91x\hat{x} N/C (a linearly increasing field)?

AM

rjnara
Jul13-06, 04:39 PM
Thanks guys :)

arunbg
Jul14-06, 05:37 AM
Well, tell us how you obtained your answer and answer Andrew's questions.