Question

In the circuit given below, the charge in $\mu C$, on the capacitor having $5\, \mu F$ is

• A. 4.5
• B. 9
• C. 7
• D. 15

Answer 1

Answer: (B)

Potential difference across the branch de is $6\, V$.
Net capacitance of de branch is $2.1\, \mu F$
So, $q=C V$
$\Rightarrow q=2.1 \times 6 \,\mu C$
$ \Rightarrow q=12.6 \,\mu C$
Potential across $3\, \mu F$ capacitance is
$V =\frac{12.6}{3}=4.2 \,Volt$
Potential across $2$ and $5$ combination in parallel is
$6-4.2=1.8 \,V$
So, $q'=(1.8)(5)=9\, \mu C$