00:01
So for this problem, we have this capacitor configuration.
00:05
I'm going to just take the time to draw it.
00:08
So i can clearly discuss it.
00:12
And so we have these two in parallel.
00:22
And we have one over here.
00:28
Let me see, i hope i remember that right.
00:33
Take another look at the picture.
00:36
Yeah, looks good to me.
00:39
And then we have points a.
00:46
Oh, these aren't really, those aren't connected.
00:48
Okay.
00:55
So we have a and b, and i think d is over here, and then where's our c? so, all right, i don't really see a d, a c, so i'll just leave that.
01:10
And then i think this was c1 at the top, c2, c3.
01:22
And c1, so it's 6, 3, and 5.
01:27
So c1 is 6 micro -faird, c -2 is 3 micro -faird, and then c -3 is 5 micro -fairad.
01:47
So, okay, and then the first question asks us to, okay, so we're connected to a voltage vab, and then after the charge and the capacitor of reach your final values, c2 has a charge of 4 times 10 to the minus 6 coulones.
02:19
And then you want to get the charges on c1 and c3.
02:23
So basically what we need to do is think about so like what stays the same and what changes for capacitors in parallel and series.
02:36
So i like to remember, so let's see, capacitors in parallel are going to have the same voltage, just because any two things in parallel have the same voltage.
02:50
So the charges will kind of move around to accommodate that.
02:54
So then you can say that v1 equals v2, and then you can use the formula for v1.
03:03
So if c is q over v, then v is q over v, then v is q over c.
03:06
C, then you can do q1 over c1 equals q2 over c2.
03:14
And so i think the question actually asks us to find the charges.
03:17
Yeah, we want to find the charges on the other ones.
03:20
And so therefore, we can say that q1 is going to be just q2 times the ratio of the c's.
03:29
So that's going to be four microcolomes times six divided by.
03:36
By three, which is a half.
03:39
So i'm dividing out the capacitancees.
03:43
And with that, i got two microculums.
03:49
And then, so this network of c1 and c2 is in parallel with this network of c3.
03:57
I guess c3 isn't really a network, but you could consider a network with a singular capacitor.
04:03
And so, yeah, so then therefore they're going to have.
04:09
The same voltage drop across both of them or both networks.
04:15
So you can say v1, 2 equals v3.
04:21
So let's start with v3.
04:23
That's easier.
04:24
So that's q3 over c3.
04:29
And then we want to get the voltage drop across these.
04:32
And so i guess you can just really use, you can use either, i guess.
04:38
So the voltage drop across this network is going to be q1 over c1.
04:47
Oh, i guess because, well, c1, and let me think about this, because this was kind of against my intuition.
04:55
So with that, i get that q3 is equal to the ratio of the capacitance is of three and one to q1...