Question

State and explain the laws of refraction of light?

Answer 1

Meaning of refraction of light:

1. Bending of light rays when it passes from one medium to another medium with different optical densities.

2. It can also be defined as the change in direction of a light wave when it passes from one medium to another.

Laws of refraction:

1. The incident ray, the normal ray, and the refracted ray lie in the same plane at the point of incidence.

As it can be clearly seen from the diagram the incident ray, the normal ray, and the refracted ray lie in the same plane at the point of incidence.

2. Snell's law:

1. Snell’s law gives the degree of refraction and relation between the angle of incidence, the angle of refraction, and refractive indices of a given pair of media.
2. We know that light experiences refraction or bending when it travels from one medium to another medium.
3. Snell’s law predicts the degree of the bend.
4. It is also known as the law of refraction.
5. In 1621, Willebrord Snell discovered the law of refraction, hence called Snell’s law.
6. Snell’s law is defined as “The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for the light of a given color and for the given pair of media”.
7. Snell’s law formula is expressed as: $\begin{array}{l}\frac{sini}{sinr}=constant={\mu }_1^2\end{array}$, where i is the angle of incidence and r is the angle of refraction. This constant value is called the refractive index of the second medium with respect to the first.