Refractive Index
Refractive index of a material is defined as the ratio of the speed of light in a vacuum (c) to the speed of light in the material (v). It describes how light propagates through a material. It is given as
n = c/v
where,
- n is refractive index
- c is speed of light in vacuum
- v is speed of light in medium
- The absolute refractive index of the medium is the ratio of the velocity of light in air or vacuum to that in the given medium. The velocity of light is maximum in a vacuum. The velocity in any other medium is less than the value in air. Thus, the absolute refractive index of the medium is always greater than unity.
Factors Affecting Refractive Index
- Refractive index of the medium depends on the nature and temperature of the medium. It also depends on the colour of the light ray.
- Refractive index is an optical property. Therefore, any impurity added to the medium will change the refractive index of the medium.
Ray Optics – Definition, Formula, Applications
Ray Optics is the study of properties of light and optical instruments by assuming that light travels in a straight line. It is also known as geometrical optics, which deals with the geometry of light. Light always travels in a straight line, and the direction in which the light rays propagate is called the ray of light. It studies the principles and laws governing the propagation of light, particularly in the absence of wave effects such as interference and diffraction.
In this article, we will learn about ray optics, reflection, refraction, concave and convex mirrors, lenses, and formulas related to them.