Four parallel metal plates P1, P2, P3, and P4, each of area 7.50 cm2, are separated successively by a distance d = 1.06 mm, as shown in the figure below. P1 is connected to the negative terminal of a battery, and P2 to the positive terminal. The battery maintains a potential difference of 12.0 V.
(a) If P3 is connected to the negative terminal, what is the capacitance of the three-plate system P1P2P3?
(b) What is the charge on P2?
(c) If P4 is now connected to the positive terminal of the battery, what is the capacitance of the four plate system P1P2P3P4?
(d) What is the charge on P4?
The Attempt at a Solution
I tried drawing the circuit in a simple way, i had no idea, i tried it once using parallel (P1P2, P2P3) and failed, i tried it in series, also p1p2 and p2p3... it is wrong... i have no idea how the circuit looks like, i have no clue how to solve it, and it is due in less than 3 hours :P ... any tip would be appreciated