The equivalent capacitance of a combination of connected capacitors shown in the figure between the points $$\mathrm{P}$$ and $$\mathrm{N}$$ is

12 $$\mu$$C and 6 $$\mu$$C charges are given to the two conducting plates having same cross-sectional area and placed face to face close to each other as shown in the figure. The resulting charge distribution in $$\mu$$C on surfaces A, B, C and D are respectively,

Find the equivalent capacitance between A and B of the following arrangement :

Three concentric metallic shells A, B and C of radii a, b and c (a < b < c) have surface charge densities +$$\sigma$$, $$-$$$$\sigma$$ and +$$\sigma$$ respectively. The potential of shell B is