1. The problem statement, all variables and given/known data Four resistors connected to a battery are shown in the figure (at bottom). The switch S2 is closed and switch S2 is left open. What is the magnitude of the potential difference Vcd 2. Relevant equations Rp= Σ(1/Ri)-1 Rs = ∑Ri V = IR 3. The attempt at a solution Seeing as c and d aren't directly connected since S2 is open, I attempted to find the total resistance using the two resistance equations above and from that find the total current. After that, I divided the total current by two since the total resistance on both sides are the same, and multiplied that by the total of the top resistance. Next I added the current multiplied by the bottom left resistor and subtracted the current multiplied by the bottom right resistor, but I don't think this is correct.