Question

Each capacitor shown in figure has capacitance of $5.0\mu F$.The emf of the battery is 50 V .How much charge will flow through AB if the switch S is closed?

Answer 1

When the switch S is closed no current flow through the capacitor since the wire through S provides an equipotential and the two capacitors in parallel to each other can be replaced by an equivalent capacitor

The equivalent capacitance is :

$C=C_1+C_2=10\mu F$

Using the relation between the capacitance and tyhe charge of a capacitor:

$Q=CV$

$Q=10\times {10}^{-6}\times 50=5\times {10}^{-4}C$