In the circuit shown in the figure,the total charge is $750\, \mu C$ and the voltage across capacitor $C_{2}$ is $20\, V$. If $C_{3} = 8\, \mu F$,then the charge on capacitor $C_{2}$ is $....\mu C$.

Three capacitors $A, B$ and $C$ are connected with a battery of $emf$ $\varepsilon$. All capacitors are identical initially. If a dielectric slab is inserted between the plates of capacitor $A$ slowly with the help of an external force,then:

$A$ fully charged capacitor of capacity $C$ is discharged through a small resistance wire embedded in a solid block of specific heat $s$ and mass $m$ under thermally isolated conditions. If the temperature of the block is raised by $\Delta T$,the initial potential difference across the capacitor is

See the diagram. The area of each plate is $2.0 \,m^{2}$ and $d=2 \times 10^{-3} \,m$. $A$ charge of $8.85 \times 10^{-8} \,C$ is given to plate $Q$. Then the potential of $Q$ becomes (in $\,V$)

In the given capacitive network,the resultant capacitance between points $A$ and $B$ is: (in $\mu F$)

$A$ network of four capacitors with capacitances $C_1 = C$,$C_2 = 2C$,$C_3 = 3C$,and $C_4 = 4C$ is connected to a battery of potential $V$ as shown in the figure. The ratio of the charges on $C_2$ and $C_4$ is: