Unit VI: Optics              (Chapter 9 Ray Optics)

Reflection of light, spherical mirrors, mirror formula. Refraction of light, total internal reflection, and its applications, optical fibres, refraction at spherical surfaces, lenses, thin lens formula, lens maker's formula. Magnification, power of a lens, combination of thin lenses in contact combination of a lens and a mirror. Refraction and dispersion of light through a prism.Scattering of light–blue colour of the sky and reddish appearance of the sun at sunrise and sunset. Optical instruments: Human eye, image formation, and accommodation, correction of eye defects (myopia and hypermetropia) using lenses.Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers.