1. The problem statement The capacitors in the figure are initially uncharged and are connected, as in the diagram, with switch S open. The applied potential difference is Vab = + 210 V. What is the potential difference Vcd? 2. Relevant equations (series) 1/C = 1/c1 + 1/c2 + ... (parallel) C = c1 + c2 + ... C=Q/V 3. The attempt at a solution Trying to find Vcd: I first found the equivalent capacitance of the series, which is 4*10-6 F. I calculated the charge on the capacitors using Q = CV, which was 8.4*10-4. Then, I tried to find Vad and Vac by using V=Q/C. I don't think this is the right way to do this problem though.