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

Woodward-hoffmann rules, Woodward-Hoffmann rules: These Rules govern t...

Woodward-Hoffmann rules: These Rules govern the formation of products throughout certain types of organic reactions.

Find leakage resistance, A set of open circuit test and short circuit test ...

A set of open circuit test and short circuit test have been performed on a transformer. A supply voltage of 480 V is applied to the primary side of the transformer and the followin

Functions, Define the function f(x)=2x/1-x^2. Find the number of distinct r...

Define the function f(x)=2x/1-x^2. Find the number of distinct real solutions of the equation f^(5)(x)=x. Details and assumptions f^(n)(x) denotes the function f applied n times. I

Particle function, Particle function: Protons The number of proton...

Particle function: Protons The number of protons in an atom determines the kind of material: Eg. Hydrogen 1 proton Helium 2 protons Lithium 3 protons B

V-i characteristics of constant current source, V-I  Characteristics  ...

V-I  Characteristics  of  Constant  Current  Source A  source  which  has  high  internal resistance  (or  impedance)  as  compared  to  load  resistance  (or  impedance)  i

Estimate the specific heat for the substance, It takes 46.0 J to raise the ...

It takes 46.0 J to raise the temperature of an 10.1 g piece of unknown substance from 13.0 o Cto  40.1 o C. What is the specific heat for the substance?

How is quantum theory conceptual view explained, How is quantum theory conc...

How is quantum theory conceptual view explained? Quantum theory gives us with the rules and regulations of the small world. The quantum theory conceptual foundation is mysterio

Michelson inferometre experiment, Why the fringes are in circular form and ...

Why the fringes are in circular form and how does it form?

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