Question

Five conducting parallel plates having area $A$ and separation between them $d$, are placed as shown in the figure. Plate number $2$ and $4$ are connected with wire and between $A$ and $B$, a cell of emf $E$ is connected. Find the charge flown through the cell.

Answer 1

Net capacitance

$=\frac{\left(\frac{2{\in }_{0}A}{d}\right)\left(\frac{{\in }_{0}A}{d}\right)}{\frac{2{\in }_{o}A}{d}}$

$=\frac{2}{3}\frac{{\in }_{0}A}{d}$

Charge flown $=CE$

$=\frac{2}{3}\frac{{\in }_{0}A}{d}E$