The figure shows four graphs, P to S, of the potential V against the distance r from a centre, with V zero very far away. Match each system with its graph. R is the radius where marked. List-I (System) A. A point charge B. A thin charged spherical shell C. A uniformly charged solid insulating sphere D. The equatorial line of an electric dipole List-II (Graph) I. Graph Q II. Graph S III. Graph P IV. Graph R

Fig. 1: Four small graphs in two rows, labelled P, Q, R and S, each with the potential V on the vertical axis and the distance r from a centre on the horizontal axis. In P, V is highest at r equal to zero and falls gently along a curve to r equal to R, where it joins a steeper curve that keeps falling towards zero further out. In Q, V is zero for every r, a flat line along the horizontal axis. In R, V is very large near r equal to zero and falls steadily along one smooth curve towards zero. In S, V is constant from r equal to zero up to r equal to R, and then falls along a curve towards zero.