IB FA19.4

Get the FA: FA19.4.docx

OK - So here's the dealio - Capacitors add just the opposite of resistors. In parallel, they just add:

C = C1 + C2 + C3 ...

and in series they add

1/C = 1/C1 + 1/C2 + 1/C3 ...

so as you have more and more, they capacitance gets less and less, because the total voltage is divided up between all the capacitors in series.

In other words, for a capacitor, C = q/V, so V = q/C. If I have three capacitors in series, the total voltage (q/C) equals the sum of the voltages across the three (q/C1 + q/C2 + q/C3) since they are in series, all the "q"s are the same (the charge has nowhere else to go...) and so dividing by q gives the series formula. All this is explained in the instruction videos below:


The Instruction for this: