1. The problem statement, all variables and given/known data A variable air-filled capacitor of the type used in tuning radios is shown. Alternate plates are connected together, one group fixed in position (shown in dark grey), the other group capable of rotation (shown in light gray). Consider a pile of n plates of alternate polarity, each having an area A and separated from adjacent plates by a distance d. Show that this capacitor has a maximum capacitance of: C=((n-1)ε0A)/d Picture for reference 2. The attempt at a solution I'm pretty sure I am correct, but something about my approach seems.. too simple. My idea is that to find the capacitance you must simply add up the capacitance between every plate. Since if there n plates, there are n-1 separations and thus C=((n-1)ε0A)/d. I can't logically find another way to calculate the capacitance, but it can't possibly be that easy?