Question

A capacitor of $8F$ is connected as shown. Charge on the plates of the capacitor is

• A. $32C$
• B. $40C$
• C. $0C$
• D. $80C$

Answer 1

Answer: (A)

$32C$

A capacitor does not allow a direct current to pass through it, thus no current flows through $8F$ capacitor and $20\Omega$ resistor. Hence we can say that $1\Omega$ and $4\Omega$ are connected in series.

Voltage drop across $4\Omega$, $V=\frac{4}{1+4}\times 5=4$ volts

As no current flows through $20\Omega$, thus voltage drop across the capacitor is $4$ volts.

$\therefore$ Charge store the the plates of capacitor, $Q=CV$

$⟹$ $Q=8\times 4=32C$