[填空题]
Two resistors and two un4yfgr p z9 6k.b9t(wi +5belutcharged cahs*mjz:+bu : kwkf:g. pacitors are arranged as shown in (Fig. Below). Then a potential difference of 2k:bh: *gf+ w .jzmsuk:4 V is applied across the combination as shown.
(a) What is the potential at point a with switch S open? (Let $V=0$ at the negative terminal of the source.) V
(b) What is the potential at point b with the switch open? V
(c) When the switch is closed, what is the final potential of point b? V
(d) How much charge flows through the switch S after it is closed? $\mu F$