There are two laws of refraction:
1. The incident ray,the refracted ray and the normal at the point of incidence ,all lie in the same plane.
2. For two particular mediums,the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant.
To understand 3 laws of refraction first we should know what refraction is. Refraction can be defined as the change in direction of a ray or of a wave due to change in its speed. We can observe refraction very commonly when a wave passes from one medium to another. It can be at any angle other than 90 degree and 0 degree . We can say that refraction is essentially a surface phenomenon.
The 3 laws of refraction are as follows :
First law of refraction state that incident ray , refracted ray and the normal at the point of incidence all lies in a same plane.
Second law states that angle of incidence and angle of refraction is constant which is also known as Snell’s law. Snell’s law is used to describe refraction which states that for a pair of media and with a wave of single frequency the ratio of angle of incidence and angle of refraction is equal to the ratio of phase velocities in two media, to the opposite ratio of the indices of refraction. We know some objects that refracts light like water , gases. It can be any other media that has a different value of bending of light. Now the question arises that do opaque object refracts light or not and the answer is yes opaque objects do refract light.
We can use refraction in many things and one of them is for clinical use. In terms of medicine refraction can be used to detect the refractive error of our eyes. A series of test has been done to determine our clearest vision. The refractive index of any medium depends on two factors which are as following the nature of which is medium will be. And second is the colour or wavelength of the incident light.
Refraction application is used in many other things as we told you earlier one use of refraction is done in binoculars and telescope. Refraction is used to magnify the objects which we see from them. These instruments are basically used by different people with their respective needs like an astronomer use telescope to see in sky and study. Our seeing glasses also use refraction for our eyes to make images more clearly for us to see. As we see that refraction depend on the medium so when a ray passes from air to glass which means its medium is changing it is becoming rarer medium to a denser medium, it bends towards the normal drawn at the point of incidence. In this case angle of incidence is greater than angle of refraction. If we passes light from glass to air this means from denser to rarer medium the angle of refraction is greater now than angle of incidence.
Refraction plays an important role in our day to day life. There are many things instruments which use refraction for the application to be complete. As we already told that in optics refraction have it say. We all know that if refraction is not there than viewing from our looking glasses become quite difficult.
Refraction is the change in direction of a wave due to a change in its speed. This is most commonly observed when a wave passes from one medium to another at any angle other than 90° or 0°. Refraction of light is the most commonly observed phenomenon, but any type of wave can refract when it interacts with a medium, for example when sound waves pass from one medium into another or when water waves move into water of a different depth. Refraction is described by Snell's law, which states that the angle of incidenceθ1is related to the angle of refraction