Question

Two capacitors of capacity `6 muF` and 3 muF` are charge `100 V` and `50 V` separately and connected as shown in Now all the three switches `S_(1),S_(2)`, and `S_(3)` are closed.

Which plates form an isolated system?
A. plate `1 and plate `4` separately .
B. plate `2` and plate `3` separately .
C. plate `2` and plate `3` jointly .
D. none of these.

Answer 1

Correct Answer - C
(1) `((150-x))/3+((600-x))/6-200=0`
`x=-100 muC`
Hence, final charge on `6 muF` Capacitor is
`q_(1)=700 muC` and charge on `3 muF` is `q_(2)=250 muC`
`q_(1)=(600-x) q_(2)=(150-x)`
. Plates `2` and `3` and plates `1` and `4` form isolated system.
Hence `q_(1)=q_(2)=q_(3)=x=-100 muC`.