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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.
- Show in the diagram the path of these rays after striking the water surface. The Critical Angle for the water-air surface is 48°.
- Name the phenomenon which the rays B and D exhibit.
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उत्तर
1)
2) Ray B shows the phenomenon of ‘refraction of light’ and ray D shows the phenomenon of ‘total internal reflection’.
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संबंधित प्रश्न
Draw the diagram of a right-angled isosceles prism which is used to make an invented image erect.
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is ______.
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.
How is the critical angle of a material related to its refractive index?
Draw a diagram, properly labelled, to illustrate the use of a total reflecting prism (a right-angled isosceles prism) to turn a ray of light through 180°. Name an instrument in which this device is used.
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?
The twinkling effect of star light is due to ______.
Which of the following statements about total internal reflection is true?
Optical Fibres are based on the phenomenon of dispersion.
