Four capacitors and a battery are connected as shown in figure. If the potential difference across the $7\mu F$  capacitor is 6V, then which of the following statement(s) is/are correct?

 

Equivalent capacitance of network is $C_{eq}=4\mu F$ .

Charge  $Q=C_{eq} V=4V\mu C$  
The charge on the $7\mu F$  or $3\mu F$  capacitor is
$Q_2=\left(7\mu F\right)\left(6V\right)=42\mu C$  $\frac{Q_2}{2.1\mu F}=\frac{Q_1}{3.9\mu F}$
 or  $Q_1=\left(42\mu C\right)\frac{\left(3.9\mu F\right)}{\left(2.1\mu F\right)}=78\mu C$
$Q=Q_1+Q_2=(78\mu C+42\mu C)=120\mu C=4V\mu C$
Emf of the battery is  $V=30V$
The potential drop across $7\mu F$  capacitor is
$\frac{Q}{12\mu F}=\frac{120\mu C}{12\mu F}=10V$