The equivalent capacitance between $A$ and $B$ is

Ten capacitors are joined in parallel and charged with a battery up to a potential $V$. They are then disconnected from the battery and joined again in series. The potential of this combination will be ....... $V$.

Three capacitors each of capacitance $1\,\mu F$ are connected in parallel. To this combination,a fourth capacitor of capacitance $1\,\mu F$ is connected in series. The resultant capacitance of the system is.......$\mu F$

Four metallic plates,each of surface area (of one side) $A$,are placed at a distance $d$ apart from each other. The two outer plates are connected to a point $P$ and the two inner plates are connected to another point $Q$ as shown in the figure below. Then,the capacitance of the system is

The potential at the point $B$ in the given figure is . . . . . . $V$.

Three capacitors each of $4\,\mu F$ are to be connected in such a way that the effective capacitance is $6\,\mu F$. This can be done by connecting them: