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प्रश्न
The figure shows a ray of light falling normally on the face AB of an equilateral glass prism having refractive index`3/2`, placed in water of refractive index `4/3`.Will this ray suffer total internal reflection on striking the face AC? Justify your answer.
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उत्तर
For total internal reflection to happen at AC face, `sin theta >= mu_"water"/mu_"prism" = "4/3"/"3/2" = 8/9 = 0.89` where, θ is angle of incidence.
Now from the figure, we can see that angle of incidence will be 60 degrees.
So `sin 60 = sqrt3/2 = 0.866` which is less than 0.89
So total internal reflection will not take place at the face AC
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संबंधित प्रश्न
Swarali has got the following observations while doing an experiment. Answer her questions with the help of observations.
Swarali observed that the light bent away from the normal, while travelling from dense medium to rarer medium. When Swarali increased the values of angle of incidence (i), the values of angle of refraction (r) went on increasing. But at a certain angle of incidence, the light rays returned into the dense medium.
So, Swarali has some questions. Answer them –
a) Name this certain value of ‘i ’. What is the value of ‘r’ at that time ?
b) Name this process of returning of light in dense medium. Explain the process.
The observation made by Swarali while doing the experiment is given below. Based on these write answers to the questions:
Swarali found that the light ray travelling from the denser medium to rarer medium goes away from the normal. If the angle of incidence (i) is raised by Swarali, the angle of refraction (r) went on increasing. However, after certain value of the angle of incidence the light ray is seen to return back into the denser medium.
Questions:
- What is the specific value of∠i called?
- What is the process of reflection of incident rays into denser medium called?
- Draw the diagrams of three observations made by Swarali.
(i) Define critical angle.
(ii) State one important factor which affects the critical angle of a given medium.
Make the correct choices for each of the following :
Total Internal reflection takes place when
(where ∠i = angle of incidence, ∠r = angle of refraction, ∠C = critical angle)
If a ray of light passes from medium I to medium II without any change of direction, what can be said about the refractive indices of these media (angle I is not 0)?
Explain ‘mirage’ as an illustration of refraction.
Solve Numerical example.
A monochromatic ray of light is incident at 37° on an equilateral prism of refractive index 3/2. Determine angle of emergence and angle of deviation. If angle of prism is adjustable, what should its value be for emergent rays to be just possible for the same angle of incidence?
For total internal reflection to take place, the angle of inddence i and the refractive index µ of the medium must satisfy the inequality ____________.
The outer concentric shell in optic fiber is called ______.
A light is entering from one medium refractive index `("RI" =5/3)` to another medium at an angle 30°. The angle of refraction for other medium is sin-1 `(5/6)`. then the increase in angle of incidence is ______ such that the ray of light reflected back into the same medium.
