The capacitance of an isolated conducting sphere of radius $R$ is proportional to . . . . . . .

Consider a charged cylindrical capacitor. The magnitude of the electric field $\vec{E}$ in its annular region:

Two spherical conductors $A$ and $B$ of radii $a$ and $b$ $(b > a)$ are placed concentrically in air. The two are connected by a copper wire as shown in the figure. Then the equivalent capacitance of the system is

If $27$ identical charged conducting spheres each of capacitance $10 \mu F$ combine to form a big sphere,then the capacitance of the big sphere is: (in $\mu F$)

$1000$ small water drops,each of capacitance $C$,join together to form one large spherical drop. The capacitance of the bigger sphere is ......... $C$.

$A$ sphere of $4\, cm$ radius is suspended within a hollow sphere of $6\, cm$ radius. The inner sphere is charged to a potential of $3\, e.s.u.$ and the outer sphere is earthed. The charge on the inner sphere is.....$e.s.u.$