1. Three equal capacitors, all with values C, are in series with a battery of V volts. If the middle capacitor is changed to 2C, what will be the resultant potential across each capicitor? Express your answer in terms of V. 2. Relevant equations C = Q / V 3. The attempt at a solution Initially, when the capacitors are equal, the total voltage will be distrubuted evenly over the capacitors (Kirchhoffs law). Therefore the potential over each = V / 3 If one of the capacitors value is doubled, then following the relation V = Q /C, the potential diffence of the middle capacitor will be halved. End of attempt However the next question goes on to discuss the affect of this on the charge per plate. By rearrangement - Q = VC, so if the capacitance is doubled, so should the charge. But then this contradicts the value for V previoulsy found? Many Thanks!