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प्रश्न
Name the principle on the basis of which optical fibres work.
On what principle does optical fibre work?
Name the physical principle of optical fibers.
Name the physical principle on which the working of optical fibers is based.
Answer the following question briefly and to the point:
Name the physical principle on the basis of which optical fibres work.
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उत्तर
Optical fibres work on the principle of total internal reflection.
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संबंधित 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.
What do you understand by the deviation produced by a prism? Why is it caused?
State two conditions necessary for total internal reflection to occur.
In the given figure PQ and PR are the two light rays emerging from an object P. The ray PQ is refracted as QS.
- State the special name given to the angle of incidence ∠PQN of the ray PQ.
- What is the angle of refraction for the refracted ray QS?
- Name the phenomenon that occurs if the angle of incidence ∠PQN is increased.
- The ray PR suffers partial reflection and refraction on the water-air surface. Give reason.
- Draw in the diagram the refracted ray for the incident ray PR and hence show the position of image of the object P by the letter P’ when seen vertically from above.
Prove the statement.
A rainbow is the combined effect of the refraction, dispersion, and total internal reflection of light.
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.
(a) A ray of monochromatic light enters glass PQRS as shown in the fig. Complete the path of ray till it emerges from the glass. (Critical angle of glass is 420).
(b) Draw diagram of a prism periscope.
(c) What are the advantages of total internal reflecting prism over plane mirror?
Describe the construction and working of an optical fibre.
Which one of the following is NOT the correct formula for refractive index of glass w.r.t. air (aμg) (i = angle of incidence, r = angle of refraction)
