00:01
Okay, we know that flux is, we need to integrate electric field through the area, right, e dot.
00:08
So, dot product, as you know, is, it comes from with the cosine of theta between them, right? so, that's the key here.
00:21
And we have three surfaces here, okay? so, surface one is this base, surface two is the lateral base or lateral surface, and surface three is this base.
00:34
So, let's find out.
00:36
First base is, so the area points this way.
00:42
So, the area, the flux there in the first surface, e in the i direction, dot or multiply by area of the first one, first base pi, four squared, and the angle is cosine of 180.
01:03
You see that? they're opposite.
01:04
So, that's negative one.
01:06
So, you will get negative 16 pi here, newton meter square per coulomb.
01:15
And then, number two, lateral surface, lateral surface, the flux here is going to be e times the lateral surface area times, the angle is always cosine of 90...