1. The problem statement, all variables and given/known data Two capacitors C1 and C2 are charged to 120V and 200V respectively.It is found that on connecting them together the potential on each one of them can be made zero.Then, A)3C1=5C2 B)3C1 + 5C2=0 C)9C1=4C2 D)5C1=3C2 2. Relevant equations Q=CV Q-charge on capacitor C-capacitance V-potential diff across plates Capacitors in parallel have same potential difference 3. The attempt at a solution After charging the capacitors to their respective voltages,the charges on them are: On C1: 120C1 and -120C1 On C2: 200C2 and -200C2 Now,when we connect them in parallel,according to question,potential across them becomes zero. Through Q=CV, if V=0,Q=0 as well... So there's no charge on any capacitor So,the total charge on them ought to be zero..i.e..120C1+200C2=0 Option B But,the answer given is A. I think..maybe my assumption of "connecting them together" in the question as a parallel configuration is wrong..maybe something else..