For the given circuit,find the voltage across the $2\ \mu F$ capacitor. (in $V$)

Four equal capacitors are connected to a $10 \, V$ battery as shown in the figure. The potentials of $A$ and $B$ are:

$n$ identical capacitors are connected in parallel and charged to a potential $V$. Now,they are disconnected and reconnected in series. What will be the total energy and potential difference of the combination?

As shown in the figure,four capacitors each of capacitance $25 \, \mu F$ are connected. The voltmeter reads $200 \, V$. Find the charge on each plate of the capacitors.

Two neutral conducting spheres of diameters $8 \ cm$ and $2 \ cm$ separated with a distance of $15 \ cm$ between their centres are joined by a thin conducting wire. $A$ charge of $100 \ nC$ is given to one of the spheres and the system is allowed to reach electrostatic equilibrium. The electric potential at a point on the line joining the centres of the two spheres where the net electric field becomes zero is . . . . . . $V$. (Neglect the charge acquired by the wire and $\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9 \ Nm^2 C^{-2}$)

Twenty-seven drops of the same size are charged at $220 \, V$ each. They combine to form a bigger drop. Calculate the potential of the bigger drop (in $V$).