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

Describe the physical processes contributing , a. Which materials are condu...

a. Which materials are conducting to which other materials? Water conducting can Can conduct bubble wrap Can to cotton wrap b. Which layers are insulating?

Gauss law, Gauss' law: The electric flux by a closed surface is propor...

Gauss' law: The electric flux by a closed surface is proportional to the algebraic total of electric charges contained in that closed surface; in differential form, div E =

Explain about the coriolis effect, The Coriolis effect is a deflection of m...

The Coriolis effect is a deflection of moving objects when they are reflects in a rotating reference frame. In a reference frame with clockwise rotation, the deflection is to the l

Radial magnetic filed in galvanometer, How theta between plane of the coil ...

How theta between plane of the coil and magnetic field remains constant

Interference of light, Two slits in young''s double slit experiment are ill...

Two slits in young''s double slit experiment are illuminated by two different sodium lamps emitting light of same wavelength . Do you observe any interference pattern on the screen

Explain direct current (dc), Direct Current (DC): Such a current can be...

Direct Current (DC): Such a current can be getting by connecting the two ends of a conductor to the terminals of the battery. This current doesn't change the direction

What are the methods for producing ultrasonic waves, What are the methods f...

What are the methods for producing Ultrasonic waves? Ultrasonic Production: Three methods there for producing Ultrasonic waves are as given below: a. Mechanical generator

Schrodinger Equation, For what purpose do we use Schrodinger equation in ou...

For what purpose do we use Schrodinger equation in our daily life?

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

Calculate the thickness of the crystal, The refractive indices of a do...

The refractive indices of a double refracting crystal for extraordinary and ordinary ray are 1.584 and 1.592 respectively for wavelength 5600A 0 . Calculate the thic

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