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).

Question

$\begin{array}{1 1} 30 \times 10^4\;V \\ 2.92 \times 10^4\;V \\ 25 \times 10^6\;V \\ 30 \times 10^4\;V\end{array} $