In Fig. 25-36, the capacitances are $C_{1}=1.0 \mu \mathrm{F}$ and $C_{2}=3.0 \mu \mathrm{F},$ and both capacitors are charged to a potential difference of $V=100 \mathrm{V}$ but with opposite polarity as shown. Switches $\mathrm{S}_{1}$ and $\mathrm{S}_{2}$ are now closed. (a) What is now the potential difference between points $a$ and $b ?$ What now is the charge
on capacitor (b) 1 and (c) 2$?$