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:

1:42 Adding Parallel Capacitors

3:19 Adding Series Capacitors

1:35 Capacitance Network