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प्रश्न
Which of the following is not involved in formation of a rainbow?
पर्याय
refraction
angular dispersion
angular deviation
total internal reflection
उत्तर
Angular deviation
Explanation:
A rainbow is created when raindrops that are suspended in the air scatter sunlight. We perceive a rainbow because of the way light refracts when it enters a raindrop, total internal reflection from the rear of the droplet surface, and further refracted out in the atmosphere. So all the given process i.e total internal reflection, refraction, and dispersion take place in the rainbow formation. Angular deviation of light doesn't occur in the formation of a rainbow.
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संबंधित प्रश्न
State the conditions required for total internal reflection of light to take place
Angle of deviation is the angle which the ______ ray makes with the direction of ______ray.
What do you understand by the deviation produced by a prism? Why is it caused?
What is total internal reflection?
State two conditions necessary for total internal reflection to occur.
Write the necessary conditions for the phenomenon of total internal reflection to
occur ?
i) Observe the given figure and answer the following questions.
a) Identify and write the natural process shown in the figure.
b) List the phenomena which are observe in this process.
c) Redraw the diagram and show above phenomena in it.
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 does a ray of light bend when it travels from rarer to denser medium
How does a ray of light bend when it travels from denser to rarer medium.
Write down the relationship between the critical angle and the refractive index of the medium.
How are critical angles related to the refractive index of the medium?
State two advantages of using a right-angle prism as a reflector, rather than a plane mirror.
Images formed by totally reflecting prisms are brighter than the image formed by ordinary reflected light, why?
How is the critical angle of a material related to its refractive index?
Complete the following diagram to show the path of the ray of a single colour in the diagram as if enters in and emerges out of the prism. Mark the angles wherever necessary. (Critical angle for glass = 42°).
PQ and PR are two light rays emerging from the object as shown in the figure below:
(i) What is the special name given to the angle of incidence (∠PQN) of ray PQ?
(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.
A ray of light is incident as a normal ray on the surface of separation of two different mediums. What is the value of the angle of incidence in this case?
Answer the following question.
Describe the construction and working of an optical fibre.
The resultant `vec"R"` of `vec"P"` and `vec"Q"` is perpendicular to `vec"P"`. Also `|vec"P"|=|vec"R"|`. The angle between `vec"P"` and `vec"Q"` is ______.
[tan 45° = 1]
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A bundle of glass threads, each of which is capable of transmitting messages using light waves is called ______.
Which of the following statements about total internal reflection is true?
What are the conditions to achieve total internal reflection?
A ray of light passes through a prism of refractive index `sqrt2` as shown in the figure. Find:
- The angle of incidence (∠r2) at face AC.
- The angle of minimum deviation for this prism.
A light is entering from one medium refractive index `("RI" =5/3)` to another medium at an angle 30°. The angle of refraction for other medium is sin-1 `(5/6)`. then the increase in angle of incidence is ______ such that the ray of light reflected back into the same medium.
Which of the following is used in optical fibres?
Small air bubbles rising up a fish tank appear silvery when viewed from some particular angle is due to the ______.
The diagram below shows a fish in the tank and its image seen in the surface of water.
Name the phenomenon responsible for the formation of this image.
