Which lens is converging —

(i) an equiconcave lens or an equiconvex lens?

(ii) a concavo-convex lens or a convexo-concave lens?

(i) An equiconvex lens or bi convex has both its surfaces convex, and is a converging lens.

(ii) A concavo-convex lens is thicker in the middle and thinner at the edges and has a converging action on a light beam. Hence, a concavo-convex lens is a converging lens.