Question

Two capacitors `C_1=1muF` and `C_2=3muF` each are charged to a potential difference of `100V` but with opposite polarity as shown in the figure. When the switch `S` is closed, the new potential difference between the points `a` and `b` is

A. `200V`
B. `100V`
C. `50V`
D. `25V`

Answer 1

Correct Answer - C
Total charge `=3xx100-1xx100=200muC`
common potential (in parallel) after S is closed is
`V=("total charge")/("Total capacity")`
`=(200muC)/(4muF)`
`=50V`