A parallel beam of light is incident on a solid glass sphere of refractive index μ = 1.5 and radius 50 cm. Find the distance of the final converging point of the emergent rays from the centre of the sphere.

The magnifying power of an astronomical telescope in normal adjustment is 10 and the focal length of its eyepiece is 20 cm. The focal length of its objective lens will be:

If the speed of light is 2.12 × 108 m/s inside the medium of an equilateral prism, find the angle of minimum deviation (δm). (Take speed of light in vacuum c = 3 × 108 m/s, sin 45° = 0.707)