Observe the given figure and write appropriate phenomenon of light in the box. - Science and Technology 1

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One Word Answer

Observe the given figure and write appropriate phenomenon of light in the box.

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Solution

Total internal refraction

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Chapter 6: Refraction of light - Answer the Following

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A rainbow is the combined effect of the refraction, dispersion, and total internal reflection of light.


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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.

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c) Redraw the diagram and show above phenomena in it.


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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:

  1. What is the specific value of∠i called?
  2. What is the process of reflection of incident rays into denser medium called?
  3. 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.


 Define critical angle for a given medium. 


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Name the principle on the basis of which optical fibres work.


How does a ray of light bend when it travels from rarer to denser medium


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