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प्रश्न
What is meant by the term ‘critical angle’?
What is a critical angle?
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उत्तर
It is the angle of incidence in the denser medium corresponding to which the angle of refraction in the rarer medium is 90°.
संबंधित प्रश्न
Draw the diagram of a right-angled isosceles prism which is used to make an invented image erect.
State two conditions necessary for total internal reflection to occur.
Draw diagram to illustrate the total internal reflection.
Plot a graph between
Angle of incidence versus angle of refraction.
(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?
Make the correct choices for each of the following :
Total Internal reflection takes place when
(where ∠i = angle of incidence, ∠r = angle of refraction, ∠C = critical angle)
Name the principle on the basis of which optical fibres work.
Write down the relationship between the critical angle and the refractive index of the medium.
Express the refractive index μ of a medium in terms of the angle of incidence i in air and the angle of refraction r in a denser medium.
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.
The adjacent diagram shows two right-angled isosceles prisms A and B. Complete the diagram to show the path of rays P and Q emerging out of the prism B. What principles have you used to complete the diagram?
Choose the correct option.
Select the WRONG statement.
A green light is incident from the water to the air-water interface at the critical angle (C). Select the correct statement.
For the same angle of incidence, the angle of refraction in four media A, B, C and D are 25°, 30°, 35° and 40° respectively. The speed of light is least in medium ______.
A particle is projected such that the horizontal range and vertical height are equal. Then the angle of projection is :
The angle of incidence at which the angle of refraction is Q£ is called the critical angle.
What are the conditions to achieve total internal reflection?
What is a mirage? How does it occur?
