Four capacitors marked with their capacitances and breakdown voltages are connected as shown in the figure. The maximum $EMF$ of the source,so that no capacitor breaks down,is: (in $kV$)

$A$ 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:

Find the equivalent capacitance across $AB$ in $\mu F$ (all capacitances are in $\mu F$).

Plates $A$ and $B$ constitute an isolated,charged parallel-plate capacitor. The inner surfaces ($I$ and $IV$) of $A$ and $B$ have charges $+Q$ and $-Q$ respectively. $A$ third plate $C$ with charge $+Q$ is now introduced midway between $A$ and $B$. Which of the following statements is not correct?

Capacitor $A$ has a capacitance of $1\ \mu F$. It is filled with a dielectric medium of constant $K = 15$. Another capacitor $B$ has a capacitance of $1\ \mu F$. Both are charged separately by $100\ V$ batteries. After charging,the batteries are removed,the dielectric is removed from $A$,and the capacitors are connected in parallel. Calculate the common potential in $V$.

In the figure, a potential of $+1200\, V$ is applied to point $A$ and point $B$ is earthed. What is the potential at point $P$ in volts?