Parallel Plate Capacitors

[farzinafsal]

great video...full explanation os a single screen makes us feel it s really easy... and fantastic explanation sir.

[glacius]

difficult topic of high school physics, nicely explained

[Rudolphhhhhh]

I am really enjoying your lectures. :-)
There is just one thing I don't agree (tell me if I am wrong because I am not 100% sure) : your choice of the vector dl, because it causes a problem with the sign of the capacitance on the two next parts of your lecture (cylindrical capacitors and spherical capacitors). Besides, you can't know if the integral of dl from 1 to 2 is +d or -d, because you didn't use any axis and didn't tell at which distance plates 1 and 2 are from an origin (contrary to the two next parts of your lecture where you specify that each shell has a different radius from the center of the cylinder or the sphere, with R1 > R2, so there is no ambiguity about the sign of the integral).

Actually, the electric potential difference V2 - V1 is equal to the negative of the work from plate 1 to plate 2, or in other words equal to the (positive) work from plate 2 to plate 1, so the vector dl should point towards plate 1 (not towards plate 2 as you told). If you choose the origin above plate 2, so that plate 1 is in distance r1 and plate 2 is in distance r2, we have r1 > r2 and r1 - r2 = +d. So, the negative of the integral from 1 to 2 is also equal to the integral from 2 to 1 (the negative signs disappears when we reverse the limits of the integral) and the integral of dl from 2 to 1 gives us r1 - r2 = +d (and so, the electric potential difference and the capacitance are really positive).
By changing the direction of the vector dl, it also solves the problem with the sign of the capacitance in the next two parts.

What do you think ?

[zmaska]

once again, I started studying to late -____- . EXAM tomorow ill be a disaster.

From now on, I'll check all the videos after my classes!!! 

[theodoreberbach]

Which video did you talk about uniform electric field