A circuit is connected as shown in the figure with the switch S open. When the switch is closed, the total amount of charge that flows from Y to X is
.

Options

A. `0`
B. `54muV`
C. `27muC`
D. `81muC`

Answer

C

Explanation

When switch is open in series combination of capacitor potential difference divides in inverse ration of capacity
`(V_(1))/(V_(2)) = (6)/(3) = (2)/(1) rArr V_(1) = (2)/(3) xx 9V = 6V`

`V_(2) = (1)/(3) xx9V = 3V`
`q_(1) = 3muF xx 6V = 18muC & q_(2) = 6muF xx 3V = 18muC`
After closing the switch is closed
`V_(1) = 3V, V_(2) = 6"volt"`
`q'_(1) = 3muF xx 3V = 9muC`
`q'_(2) = 6muf XX 6V = 18muC`
charge passes through switch `27muC` from `y` to