Two spherical conductors $A$ and $B$ of radius $a$ and $b (b > a)$ are placed in air concentrically $B$ is given charge $+ Q$ coulomb and $A$ is grounded. The equivalent capacitance of these is

What happens if the magnitude of capacitance of capacitor are large ? Define dielectric breakdown and dielectric strength.

What physical quantities may $X$ and $Y$ represent ? ($Y$ represents the first mentioned quantity)

A spherical condenser has inner and outer spheres of radii $a$ and $b$ respectively. The space between the two is filled with air. The difference between the capacities of two condensers formed when outer sphere is earthed and when inner sphere is earthed will be

Two identical thin metal plates has charge $q _{1}$ and $q _{2}$ respectively such that $q _{1}> q _{2}$. The plates were brought close to each other to form a parallel plate capacitor of capacitance $C$. The potential difference between them is.