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

Inertial frame of reference, Inertial Frame of Reference : If in a given sy...

Inertial Frame of Reference : If in a given system a free object does not experience any acceleration or force, the system is called the inertial frame. Any reference frame that mo

Explain the spinning problems, Explain the Spinning Problems The Law of...

Explain the Spinning Problems The Law of Conservation of Angular momentum states that if there is no net applied torque on a body then angular momentum is conserved. This is si

Illustrate properties of electromagnetic waves, Q. Illustrate what two prop...

Q. Illustrate what two properties of electromagnetic waves are used to attach info to radio signals? Answer:- By changing the amplitude of a radio wave you can encode info

Reasoning question from motion in 1 and 2 dimensions, make reasoning questi...

make reasoning questions from motion in 1 and 2 dimensions

Explain about the principle of acousting grating, Explain about the princip...

Explain about the principle of acousting grating. Acousting Grating Principle: While ultrasonic waves are passed by a liquid, the density of the liquid varies layer by layer

Why do you not collapse in the pressure, Q. Why do you not collapse in the ...

Q. Why do you not collapse in the pressure created by the atmosphere? Answer:- If the outward pressure inside your body weren't equal to the pressure pressing in on you an

Motion angular velocity, A scooterist is racing at a speed of 72 km per hou...

A scooterist is racing at a speed of 72 km per hour. If the radius of the wheel is 20 cm, find the angular speed of the wheels.   Ans) 72kmph=20m/s 20cm=0.2m; v=rw w=v/r w=20/0

Nucleus has negative mass defect, Tell me Is it possible that a nucleus has...

Tell me Is it possible that a nucleus has negative mass defect    If the nucleus has a mass defect it is likely that the strong force and the weak force have sustained a main

Define under - over and critically damped oscillator, Briefly explain the e...

Briefly explain the equations describing under-damped, over damped and critically damped one-dimensional harmonic oscillator?

Explain fusion reaction, Fusion Reaction: In nuclear fusion light nucle...

Fusion Reaction: In nuclear fusion light nuclei are brought together to form a relation heavier nucleus. They energy free in nuclear fusion is larger than that free in fission.

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