What is the equivalent capacitance between the points $P$ and $Q$ in the combination of capacitors shown in the figure (in $\mu F$)?

Seven capacitors,each of capacitance $2 \mu F$,are connected in a configuration to obtain an effective capacitance of $\frac{6}{13} \mu F$. The combination that will achieve this is:

The combination of capacitors with $C_1 = 3\,\mu F$,$C_2 = 4\,\mu F$,and $C_3 = 2\,\mu F$ is charged by connecting $A$ and $B$ to a battery. Consider the following statements:
$I.$ Energy stored in $C_1$ $=$ Energy stored in $C_2$ $+$ Energy stored in $C_3$
$II.$ Charge on $C_1$ $=$ Charge on $C_2$ $+$ Charge on $C_3$
$III.$ Potential drop across $C_1$ $=$ Potential drop across $C_2$ $=$ Potential drop across $C_3$
Which of these is/are correct?

Five capacitors,each of capacitance $C$,are connected as shown in the figure. The ratio of the equivalent capacitance between $P$ and $R$ to the equivalent capacitance between $P$ and $Q$ is:

Five capacitors,each of value $1 \mu F$,are connected as shown in the figure. The equivalent capacitance between $A$ and $B$ is (in $\mu F$)

Find the equivalent capacitance between $A$ and $B$ as shown in the figure (in $\mu F$).