How To Solve Any Circuit Problem With Capacitors In Series and Parallel Combinations - Physics

so in this video we're going to talk about how to calculate the charge and the voltage across the capacitor if we have capacitors in series and parallel uh combinations so let's start with this problem what's the first thing we need to do in order to calculate the charge on every capacitor now the first thing we need to do is calculate the equivalent capacitance of the entire circuit now whenever you have two capacitors in parallel with each other the total capacitance or the equivalent capacitance is simply the sum of those two capacitors so it's going to be c2 plus c3 just for this network so we can replace that with a 20 microfarad capacitor so now we have this circuit we have a 10 microfarad capacitor in series with a 20 which is in series with another 20 . now whenever you have two capacitors in series with each other and if they have the same value the equivalent capacitance of those two capacitors is going to be half of their individual values so half of 20 is 10 so i can replace these two capacitors with a single 10 microfarad capacitor now this capacitor is also 10 so the equivalent capacitance of these two will be five so that's the equivalent capacitance of the entire circuit it's five microfarads now if you wish to confirm the answer you can use the formula so let's use it with these three capacitors in series so the equivalent capacitance is going to be 1 over c one plus one over c two plus one over c three raised to the minus one