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

Honors, an orchestra tunes up for the big concert by playing an A, WHICH RE...

an orchestra tunes up for the big concert by playing an A, WHICH RESOUNDS WITH A FUNDAMENTAL FREQUWNCY OF 440HZ FIND THE SECOND AND TIRD HARMONICS OF THIS NOTE

Algebra based physics 2.., A rectangular surface (0.14 m x 0.39 m) is orien...

A rectangular surface (0.14 m x 0.39 m) is oriented in a uniform electric field of 440 N/C. What is the maximum possible electric flux through the surface?

Free-particle, Free-particle A.  Suppose that the wavefunction for a f...

Free-particle A.  Suppose that the wavefunction for a free-particle is given by the wavefunction Find the value of A that normalizes Ψ (x). B.  The Hamiltonian oper

Force act on earth, Q. A rubber ball is dropped to the floor. What forc...

Q. A rubber ball is dropped to the floor. What force act on the ball to bounce? Does the Earth "bounce" too? Ans. The force of the Earth pushing back on the ball causes

Must all illuminator have forced ventilation, Must all illuminator have for...

Must all illuminator have forced ventilation? Usually yes, the exception being which with a massive construction that dissipate heat by transfer or radiation.

Atwoods machine, Atwood's machine A weight-and-pulley system is used t...

Atwood's machine A weight-and-pulley system is used to measure the acceleration because of gravity at Earth's surface through measuring the net acceleration of a set of weight

Suidqs (super conducting quantum interference devices), SQUIDs, or super co...

SQUIDs, or super conducting Quantum interference devices are used to measure minute changes in magnetic flux by means of a pair of Josephson junctions, often used to detect extrem

Determine the elapsed time in kinematics, Q. Determine the elapsed time in ...

Q. Determine the elapsed time in kinematics? Let S = 1 + c 2 + c 4 + ........  Then, S = 1 + c 2 (1 + c 2 + c 4 +.......... ) S = 1 + c 2 S    so, S - c 2 S = 1

What are wave fronts, What are wave fronts? (Physics) A wave front is a...

What are wave fronts? (Physics) A wave front is an imaginary surface joining all points in space that are reached at the similar instant by a wave propagating by a medium. L

De broglies wavelength-nature of light, An electron is in a box of width 3*...

An electron is in a box of width 3*10^-10m.what are de broglies wavelength and magnitude of momentum of the electron if it is in A)n=1 level B)n=2 level C)n=3 level Ans)  Use 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