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प्रश्न
Total internal reflection can take place only if ______.
विकल्प
light goes from an optically rarer medium (smaller refractive index) to optically denser medium
light goes from optically denser medium to rarer
mediumthe refractive indices of the two media are close to each other
the refractive indices of the two media are widely different.
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उत्तर
Total internal reflection can take place only if the light goes from an optically denser medium to a rarer medium.
Explanation:
The angle of incidence is greater than the critical angle.
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संबंधित प्रश्न
The diagram below shows a point source P inside a water container. Four rays A, B, C, D starting from the source P are shown up to the water surface

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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.
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(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.
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The entire light is reflected back into the denser medium is called ______.
