Two rays travelling parallel to the principal axis strike a large plano-convex lens having a refractive index of 1.60 (Fig.P23.54). If the convex face is spherical, a ray near the edge does not pass through a local point (spherical aberration occurs).
Assume this face has a radius of curvature of R = 20.0 cm and two rays are at distances h1 = 0.5 cm and h2 = 12 cm from the principal axis. Find the difference Δx in the position where each crosses the principal axis.
