It is the phenomenon that occurs when a wave passes from one medium to another of different characteristics, having its direction deviated.
Regardless of each wave, its frequency does not change in refraction, however, the speed and wavelength may change.
Through refraction it is possible to explain numerous effects such as the rainbow, the color of the sky at sunset and the construction of astronomical devices.
Wave refraction obeys two laws which are:
- 1st Law of Refraction: The incident radius, the line perpendicular to the boundary at the point of incidence and the refracted radius are contained in the same plane.
- Snell's Law: This law relates the angles, velocities and wavelengths of refractive incidence, being mathematically expressed by:
Applying the law:
As shown in the figure:
As examples of refraction, waves can be used propagating on the surface of a liquid and passing through two distinct regions. It can be experimentally verified that the velocity of propagation on liquid surfaces can be altered by modifying the depth of this site. The waves decrease the velocity modulus by decreasing the depth.