Four large metallic plates of area A each are kept parallel to each other with a small separation between them as shown in the figure. A cell of emf V is connected across the two outermost plates through a switch `K_(1)`. The two inner plates are similarly connected with a cell of emf 2 V through a switch `k_(2)` Initially both switched are open and the plates, starting form left to right (i.e. number 1 to 4) are given charges `Q, 2 Q, - 2Q` and `- Q` respectively. Now answer the following questions

The charge appearing on the outer surface of plate -1, when switches `K_(1), K_(2)` are open

Options

A. zero
B. Q/e number of electrons will flow from outer to inner shell, where 'e' is the charge on an electron
C. `-Q`
D. `- 3Q`

Answer

A