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

Explain thevenin''s theorem, Thevenin's Theorem can be stated as follows: ...

Thevenin's Theorem can be stated as follows: Any two terminal network having a number of e.m.f. sources and resistances can be changed by equivalent simple series circuit of singl

Motion in one dimension, a ball is dropped from a bridge 122.5m high. afte...

a ball is dropped from a bridge 122.5m high. after the ball has been falling for2 sec another is thrown straight downwards after it. the initial velocity of the ball is such that

Calculate the entropy change in the universe, A 2kg piece of copper at 200 ...

A 2kg piece of copper at 200 o C is taken out of a furnace and is allowed to cool in air with an ambient temperature of 25 o C. Calculate the entropy change in the universe as a

What is the wavelength of that sound wave, When an orchestra is tuning up, ...

When an orchestra is tuning up, the first violinist plays a note at 256 Hz. a. What is the wavelength of that sound wave if the speed of sound in the concert hall is 340 m/s?

Thin films , Writing a paper on physics topic, select any of topic of your ...

Writing a paper on physics topic, select any of topic of your choice

Grouping of Capacitors, Hi Can u guide me how to solve numericals on Group...

Hi Can u guide me how to solve numericals on Grouping of Capacitors. Thanks & Regards Raj

Is there any way to get zero gravity on the earth?, Yes it is possible at t...

Yes it is possible at the centre of the earth where the radius is zero .

What are the basic requirements of a laser, What are the basic requirements...

What are the basic requirements of a Laser? Basic requirement of a Laser are as follows: 1. Active Medium: Active basic medium is needed to start the laser action. There

Kinematics, how to solve question for kinematics problem

how to solve question for kinematics problem

Explain about centrifugal force, Q. Explain about Centrifugal force? Th...

Q. Explain about Centrifugal force? The centrifugal force is F c =mv 2 /r, Where r is the radius of the orbit and m is the mass of the object and v is the velocity. The

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