// Scilab code Ex3.13 : Pg:115 (2008) clc;clear; P = 5; // Power of combination of a convex lens and a plano-convex lens, dioptre mu1 = 1.50; // Refractive index of crown glass mu2 = 1.60; // Refractive index of flint glass omega1 = 0.01; // Dispersive power of the crown glass convex lens omega2 = 0.02; // Dispersive power of flint glass plano-convex lens F = 100/P; // Focal length of the combination of lenses, cm f_ratio = -omega2/omega1; // Ratio of f2 to f1 // From thin lens formula, 1/F = 1/f1 + 1/f2 and as f2 = f_ratio*f1, solving for f1 f1 = -F/f_ratio; // Focal length of flint glass lens, cm f2 = f_ratio*f1; // Focal length of crown glass lens, cm mu = 1.60; // Refractive index of flint glass R2 = %inf; // Radius of curvature of the first surface of convex lens, cm // Now from lens maker's formula R1 = (mu - 1)/(1/f2+(mu-1)/R2); // Radius of curvature of second surface of convex lens, cm mu = 1.5; // Refractive index of crown glass R2 = R1; // Radius of curvature of the first surface of convex lens, cm R1_prime = (mu - 1)/(1/f1+(mu-1)/R2); // Radius of curvature of second surface of concave lens, cm printf("\nThe radii of curvature of the convex lens are = %-3.1f cm and %2.0f cm", R1_prime, R1); // Result // The radii of curvature of the convex lens are = 8.6 cm and -12 cm