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

What is the angle of refraction in the flint glass, A piece of flint glass ...

A piece of flint glass is lying on top of a container of water (see figure below). When a red beam of light in air is incident upon the flint glass at an angle of 28°. What i

Energy levels of this molecule, The microwave (rotational) spectrum of 12 ...

The microwave (rotational) spectrum of 12 C 16 O having  a series of lines spaced by 115.3 GHz. Suppose that the rotational  energy levels of this molecule can be approximated by

Kinetic friction, A 2.1 kg block slides along a horizontal surface with a c...

A 2.1 kg block slides along a horizontal surface with a coefficient of kinetic friction μ k = 0.31. The block has a speed v = 1.4 m/s when it strikes a massless spring head-on.

How does the laser printer works, Q. How does the laser printer works? ...

Q. How does the laser printer works? Answer:- When a text or else image is entered into the CPU it produces a series of varying voltages. This manages a LED (light emittin

Cell capacity, CELL CAPACITY The amount of electrical energy that a cel...

CELL CAPACITY The amount of electrical energy that a cell can provide from new to the end of its useful voltage on load is called the cell capacity and is quoted in Ampere hour

Manufacturing of transformers, Before manufacturing of transformers we must...

Before manufacturing of transformers we must know the important parts of transformer which need to be manufactured. Following are the main parts of transformers. (a)          Fo

Light., what does light does

what does light does

Ohmic, did the resistance of an ohmic conductor depends on the applied volt...

did the resistance of an ohmic conductor depends on the applied voltage

Michelson morley experiment, Michelson Morley Experiment The Michelson...

Michelson Morley Experiment The Michelson-Morley experiment was performed within the year of 1887 through Albert Michelson and Edward Morley at what is presently Case Western

Illustrate the current-voltage characteristic curves, Illustrate the curren...

Illustrate the current-voltage (I-V) characteristic curves if a junction diode in reverse and forward bias.

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