Question

Define refraction and state the law of refraction.

Answer 1

The beam of light enters in one medium from another medium. The beam of the light deviates from its path. The deviation of the beam of light is known as the refraction.

Complete step by step answer:
When the beam of light enters in medium other than the first medium. The beam of the light deflects from their straight path. The deviation of the light from its path is known as the refraction of the light.
The laws of refraction are given as:
The incident ray, reflected ray and normal always lies on the same plane.
The ratio of the sine of the angle of incidence and the sine of the angle of refraction is constant. This law is commonly known as Snell’s law.
The ratio of the angle of incident and the angle of refraction can be calculated using Snell’s law.
According to Snell’s law, when the beam of the light enters from the medium of refractive index $n_1$ to the medium having refractive index $n_2$.
The ratio of the sine of the angle and incident and the sine of angle of refraction is given as:
$\Rightarrow \dfrac{\sin {{\theta }_{1}}}{\sin {{\theta }_{2}}}=\dfrac{{{n}_{2}}}{{{n}_{1}}}$
Where, ${{\theta }_{1}}$ is the angle of incidence and ${{\theta }_{2}}$ is the angle of refraction.
The refractive index for the given medium is constant. So,
$\Rightarrow \dfrac{\sin {{\theta }_{1}}}{\sin {{\theta }_{2}}}=\text{Constant}$

Note:
When the beam of light enters in medium other than the first medium. The beam of the light either moves back in the same medium. The deviation of the light in the same medium is known as the reflection of the light.