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प्रश्न
- Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface.
- Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.
विकल्प
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If both Assertion and Reason are false.
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उत्तर
If Assertion is true but Reason is false.
Explanation:
Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface. The claim is correct.
One requirement for total internal reflection is that light goes from a denser to a rarer medium. Total internal reflection occurs in optical fibre as light passes from the core to the cladding. As a result, the core's refractive index should be larger than that of the cladding. As a result, the reason is untrue.
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संबंधित प्रश्न
What is total internal reflection?
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.
Plot a graph between
Sine of angle of incidence versus sine of angle of refraction,
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)?
PQ and PR are two light rays emerging from the object as shown in the figure below:
(i) What is the special name given to the angle of incidence (∠PQN) of ray PQ?
(ii) Copy the ray diagram and complete it to show the position of the image of the object P when seen obliquely from above.
(iii) Name the phenomenon that occurs if the angle of incidence ∠PQN is increased still further.
A ray of light is incident on a glass surface at an angle of 50° with the corresponding angle of refraction 30°. Find the value of the R.I. of glass.
Choose the correct option.
Select the WRONG statement.
Answer the following question.
Under what conditions are total internal reflection possible? Explain it with a suitable example.
The angle of minimum deviation produced by a thin glass prism in air is 'δ'. If that prism is immersed in water, the angle of minimum deviation will be ______.
( aμg = refractive index of glass w.r.t, air aμw = refractive index of water w.r.t. air)
The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur.
