It is through light and our sense of vision that we interpret and know the world around us. Intuitively, there are two things that we can mention about light from our common experience.
First, the enormous speed with which the light travels and second, that it travels in a straight line. It took some time for people to realise that the speed of light was finite and measurable. A light wave can be considered to travel from one point to the other along a straight line joining them. This straight path is known as the ray of light. A bundle of such rays constitutes a beam of light. In CBSE class 12 Physics chapter 9 Ray optics and Optical instruments, we learn about the following concepts:
- Considering the phenomenon of refraction, reflection and dispersion of light using the ray picture of light.
- Image formation by plane and spherical refracting and reflecting surfaces using the basic law of reflection and refraction.
- Construction and working of a few important optical instruments including the human eye.