What is the equivalent capacitance of the system of capacitors between $A$ and $B$?

The equivalent capacitance between $A$ and $B$ in the figure is $1\,\mu F$. Then the value of capacitance $C$ is.....$\mu F$

In the given circuit,a charge of $+80 \mu C$ is given to the upper plate of a $4 \mu F$ capacitor. At steady state,the charge on the upper plate of the $3 \mu F$ capacitor is (in $\mu C$)

All six capacitors shown are identical. Each can withstand a maximum of $200\, V$ between its terminals. The maximum voltage that can be safely applied between $A$ and $B$ is.....$V$

Three capacitors are connected to a $D.C.$ source of $100 \; V$ as shown in the figure. If the charges accumulated on plates $a, b, c, d, e,$ and $f$ are ${q_a}, {q_b}, {q_c}, {q_d}, {q_e},$ and ${q_f}$ respectively,then:

In the given circuit,a charge of $+80 \ \mu C$ is given to the upper plate of the $4 \ \mu F$ capacitor. Then in the steady state,the charge on the upper plate of the $3 \ \mu F$ capacitor is: