Hey, guys. Let's get a little bit more practice with solving equivalent capacitances and complicated circuit problems. Okay. So we've got all these 4 capacitors right here. All of them are labeled. So we know we have to work from the inside out if we have combinations. We have some parallels. We have some series. So basically, what's happening is that if I could collapse all of this down to a single capacitor, then all of these 2 basically, this one and this one will be in series with each other. But if I look a little bit more carefully, a little bit more closely, then what I have is a situation where I have these 3 capacitors, and I have these are in parallel. And if I look even closer, I've got these 2 capacitors right here are in series with each other. So what we have to do is we have to work from the inside outwards. So the step one, we're going to be solving with the equivalent capacitances of these 2. In other words, when we do that, we're going to get a circuit that basically looks like this. We're going to have an equivalent capacitance right here. We have the one on the bottom, which we know is 3 farads, and then these two things are going to be in parallel with each other, and then they're going to be in series with the 5 farad capacitor. So we need to figure out what is this CEQ right here, and that's going to be the one in red. Okay? So we know that we're dealing with a series, and we have 2 capacitors, which means we can use our shortcut equation for equivalent capacitance.

Now, both of these happen to be 4, which means that the equivalent capacitance is equal to 1 farad. Okay? Now, what I have is I have these 2, or these so this equivalent capacitor right here, and this one on the bottom. So in other words, this situation right here, and I have it in parallel. So that means I need to use my parallel equations for CEQ. And what happens is when I figure out what this equivalent capacitance is, this is going to behave the same way. So if I had a single capacitor right here, that's going to be in blue, and then that capacitor was in parallel with the 5 farad capacitor. Okay? So this equivalent capacitance right here is going to be. Well, I have them in parallel. So that means all I have to do is just add these things together. So I have 1 farad plus 3 farads is just 4 farads, and that's it. So I've got 4 farads right here. Okay? And now for the last part, the last step, the equivalent compare capacitance for the entire circuit, now I have in series. So this was parallel, and then this is going to be in series. Now I have, 2 capacitors that I have here. So I could use really either one of the equations I have. So I could use the fact that the equivalent that one over ED equivalent capacitance is going to be 1 over 4 plus 1 over 5. And let's see, 1 over 4 plus 1 over 5. The common denominator is 20. This is going to be 5 over 20. This is before over 20, so this is going to be 9 over 20, but I have to take the reciprocal once I do this. So that means that my equivalent capacitance, CEQ, is going to be 20 over 9. We could have done that. Or an alternate way, so I have Or we could have just done that the equivalent capacitance for 2 capacitors is going to be the multiplication of these 2, 4 times 5, divided by 4 plus 5, and we would have gotten the exact same thing, 20 over 9 farads. So either way, using either one of those approaches, we get the correct equivalent capacitance for the entire circuit. So that means that all of these 4 capacitors behave as if you had just had a single capacitor of 20 over 9 farads. And that's the answer. Alright? Let me know if you guys have any questions. This is a very very useful step-by-step process in how to basically work from inside out. Okay? Let me know if you guys have any questions.