Lecture 5: E = -grad V, More on Equipotential Surfaces, Conductors, Electrostatic Shielding (Faraday Cage)
recorded by: Massachusetts Institute of Technology, MIT
published: Oct. 10, 2008, recorded: February 2002, views: 3947
released under terms of: Creative Commons Attribution Non-Commercial Share Alike (CC-BY-NC-SA)
Download mit802s02_lewin_lec05_01.m4v (Video - generic video source 104.4 MB)
Download mit802s02_lewin_lec05_01.rm (Video - generic video source 79.4 MB)
Download mit802s02_lewin_lec05_01.flv (Video 215.5 MB)
Download mit802s02_lewin_lec05_01_320x240_h264.mp4 (Video 148.1 MB)
Download mit802s02_lewin_lec05_01.wmv (Video 410.4 MB)
Report a problem or upload filesIf you have found a problem with this lecture or would like to send us extra material, articles, exercises, etc., please use our ticket system to describe your request and upload the data.
Enter your e-mail into the 'Cc' field, and we will keep you updated with your request's status.
"So today no new concepts, no new ideas, you can release a little bit and I want to discuss with you the connection between electric potential and electric fields.
Imagine you have an electric field here in space and that I take a charge Q in my pocket, I start at position A and I walk around and I return at that point A.
Since these forces are conservative forces, if the electric field is a static electric field, there are no moving charges, but that becomes more difficult, then the forces are conservative forces and so the work that I do when I march around and coming back at point A must be zero. It's clear when you uh look at the equation number three that the potential difference between point A and point A is obviously zero. I g- start at point A and I end at point A and that is the integral in going from A back to point A of E dot DL and that then has to be zero.
And we normally indicate such an integral with a circle which means you end up where you started. This is a line now this is not a closed surface as we had in equation one..."
Link this pageWould you like to put a link to this lecture on your homepage?
Go ahead! Copy the HTML snippet !