(a) Two small solid metal balls A and B of radii $R$ and $2R$ having charge densities $2\sigma$ and $3\sigma$ respectively are kept far apart. Find the charge densities on A and B after they are connected by a conducting wire. OR (b) Two infinitely long straight wires '1' and '2' are placed $d$ distance apart, parallel to each other, as shown in the figure. They are uniformly charged having charge densities $\lambda$ and $-\frac{\lambda}{2}$ respectively. Locate the position of the point from wire '1' at which the net electric field is zero and identify the region in which it lies.