Refractive index, Physics

Assignment Help:

Refractive index:

The most important optical measurement for any transparent material is its refractive index (n). The refractive index is the ratio of the speed of light (c) in a vacuum to the speed of light in the medium:

The speed of light in a material is always slower than in a vacuum, so the refractive index is always greater than one in the optical part of the spectrum. Although light travels in straight lines through optical materials, something different happens at the surface. Light is bent as it passes through a surface where the refractive index changes. The amount of bending depends on the refractive indexes of the two materials and the angle at which the light strikes the surface between them.

The angle of incidence and refraction are measured not from the plane of the surfaces but from a line perpendicular to the surfaces. The relationship is known as "Snells Law", which is written; ni sin I = nr sin R, where ni and nr are the refractive indexes of the initial medium and the medium into which the light is refracted. I and R are the angles of incidence and refraction.

1747_REFRACTIVE INDEX.png

Snell's law indicates that refraction can't take place when the angle of incidence is too large. If the angle of incidence exceeds a critical angle, where the sine of the angle of refraction would equal one, light cannot get out of the medium. Instead the light undergoes total internal reflection and bounces back into the medium.

Figure  illustrates the law that the angle of incidence equals the angle of reflection. It is this phenomenon of total internal reflection that keeps light confined within a fibre optic.

23_REFRACTIVE INDEX1.png


Related Discussions:- Refractive index

Significance of quasi-fermi level with aid of band diagram, Significance of...

Significance of Quasi-Fermi Level with Aid of Band Diagram (a) Explain with diagrams different types of trap assisted generation and recombination. (b) Explain the signific

What is the wavelength of electromagnetic waves, What is the wavelength of ...

What is the wavelength of electromagnetic waves of frequency 5 x 1019Hz in free space? Give its two applications.

What are mechanical waves , The waves which needs medium for their propagat...

The waves which needs medium for their propagation are known as mechanical waves. Example : Waves on string and spring, waves on water surface, sound waves, seismic waves.

Explain the vector addition of velocity, Explain the Vector Addition of Vel...

Explain the Vector Addition of Velocity Of course the velocity is relative to how you indicate the position d. If you are moving in water that is itself moving, then your full

Galvanometer., why horse shoe magnet is use in galvanometer

why horse shoe magnet is use in galvanometer

Scanning, Scanning is process of dividing an image on the screen into a lar...

Scanning is process of dividing an image on the screen into a large number of very small squares formed by sets of horizontal and vertical straight lines.   Iconoscope i

Presbyopia, Presbyopia: The accommodation power of a person is lost by ...

Presbyopia: The accommodation power of a person is lost by which the suffers a long sightedness. It is known as Presbyopia or lack of accommodation.

Identify the key terms in wave function, Identify the key terms in the wave...

Identify the key terms in the wave function provided by

Electromagnetic radiations, Electromagnetic radiations: What are the c...

Electromagnetic radiations: What are the common features among all the Electromagnetic radiations? Ans: 1. They all can be described in terms of oscillating electric and ma

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd