What are the Laws of refraction of Light?
Answers
Answer:
Snell's law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.
Explanation:
Causes of Refraction
Change of Speed Results in Change in Direction
A light ray refracts whenever it travels at an angle into a medium of different refractive index. This change in speed results in a change in direction. As an example, consider air travelling into water. The speed of light decreases as it continues to travel at a different angle.
Refraction of Light
Refraction of light in glass is shown in the figure above. When light travels from air into glass, the light slows down and changes direction slightly. When light travels from a less dense substance to a denser substance, the refracted light bends more towards the normal line. If the light wave approaches the boundary in a direction that is perpendicular to it, the light ray doesn’t refract in spite of the change in speed.
Laws of Refraction of Light
Laws of refraction state that:
The incident ray refracted ray, and the normal to the interface of two media at the point of incidence all lie on the same plane.
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. This is also known as Snell’s law of refraction.
sinisinr=constant
Watch the video below to understand the process of refraction in detail
What is Refractive Index?
Refractive index, also called the index of refraction describes how fast light travels through the material.
Refractive Index is dimensionless. For a given material, the refractive index is the ratio between the speed of light in a vacuum (c) and the speed of light in the medium (v). If the refractive index for a medium is represented by n, then it is given by the following formula:
n=cv
Based on the refractive index of the medium, the light ray changes its direction, or it bends at the junction separating the two media. If the light ray travels from a medium to another of a higher refractive index, it bends towards the normal, else it bends away from the normal.
Refraction of Light in Real Life
Mirage and looming are optical illusions which are a result of refraction of light.
A swimming pool always looks shallower than it really is because the light coming from the bottom of the pool bends at the surface due to refraction of light.
Formation of a rainbow is an example of refraction as the sun rays bend through the raindrops resulting in the rainbow.
When white light passes through a prism it is split into its component colours – red, orange, yellow, green, blue and violet due to refraction of light.
Applications of Refraction of Light
Refraction has many applications in optics and technology. A few of the prominent applications are listed below:
A lens uses refraction to form an image of an object for various purposes, such as magnification.
Spectacles worn by people with defective vision use the principle of refraction.
Refraction is used in peepholes of house doors, cameras, movie projectors and telescopes.