Two capacitors $C_1$ and $C_2$ are charged to $120\ V$ and $200\ V$ respectively. It is found that connecting them together the potential on each one can be made zero. Then

Eight drops of mercury of equal radii possessing equal charges combine to form a big drop. Then the capacitance of bigger drop compared to each individual small drop is……..$times$

Two identical charged spherical drops each of capacitance $C$ merge to form a single drop. The resultant capacitance is

A cylindrical capacitor has two co-axial cylinders of length $15\; cm$ and radii $1.5 \;cm$ and $1.4\; cm .$ The outer cylinder is earthed and the inner cylinder is given a charge of $3.5\; \mu \,C .$ Determine the capacitance of the system and the potential of the inner cylinder. Neglect end effects (i.e., bending of field lines at the ends).

The charges on two plates of a $10\,\mu f$ capacitor are $5\,\mu C$ and $15\,\mu C$ then the potential difference across the capacitor plates is……..$V$