In an isolated parallel plate capacitor of capacitancee `C`, the four surface have chrges `Q_(1),Q_(2),Q-(3)` and `Q_(4)` as shown. The potential difference between the plates is

Options

A. `(Q_(1)+Q_(2)+Q_(3)+Q_(4))/(2C)`
B. `(Q_(2)+Q_(3))/(2C)`
C. `(Q_(2)-Q_(3))/(2C)`
D. `(Q_(1)+Q_(4))/(2C)`

Answer

C

Explanation

Facing surface have equal and opposite charges
`Q_(3)=-Q_(2)`
charge on capacitor `Q_(2) or -Q_(3)`
`V=(Q-(20))/(c)`
`V=(-Q_(3))/(c)`….(ii)
`(i)+(ii)`
`2V=(Q_(2)-Q_(3))/(c)impliesV=(Q_(2)-Q-930)/(2C)`