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).

This question has Statement $1$ and Statement $2$. Of the four choices given after the Statements, choose the one that best describes the two Statements.

Statement $1$ : It is not possible to make a sphere of capacity $1$ farad using a conducting material.
Statement $2$ : It is possible for earth as its radius is $6.4\times10^6\, m$

Dimension of Capacitance is

The capacity of a parallel plate condenser is $15\,\mu \,F$, when the distance between its plates is $6 \,cm$. If the distance between the plates is reduced to $2\, cm$, then the capacity of this parallel plate condenser will be……$\mu \,F$

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.