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प्रश्न
Choose the correct option.
Select the WRONG statement.
पर्याय
Smaller angle of prism is recommended for greater angular dispersion.
Right-angled isosceles glass prism is commonly used for total internal reflection.
Angle of deviation is practically constant for thin prisms.
For emergent rays to be possible from the second refracting surface, certain minimum angle of incidence is necessary from the first surface.
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उत्तर
Smaller angle of prism is recommended for greater angular dispersion.
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संबंधित प्रश्न
You are given prisms made of crown glass and flint glass with a wide variety of angles. Suggest a combination of prisms which will
(a) deviate a pencil of white light without much dispersion,
(b) disperse (and displace) a pencil of white light without much deviation.
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
1) Show in the diagram the path of these rays after striking the water surface.
The Critical Angle for the water-air surface is 48°.
2) Name the phenomenon which the rays B and D exhibit.
Draw the diagram of a right-angled isosceles prism which is used to make an invented image erect.
What do you understand by the deviation produced by a prism? Why is it caused?
Name two factors which affect the critical angle for a given pair of media. State how do the factors affect it.
Draw diagram to illustrate the total internal reflection.
Total internal reflection occurs only when a ray of light passes from a ______ medium to a ______ medium.
Two isosceles right-angle glass prisms P and Q are placed near each other as shown in Fig. Complete the path of the light ray entering the prism P till it emerges out of the prism Q.
Swarali has got the following observations while doing an experiment. Answer her questions with the help of observations.
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.
So, Swarali has some questions. Answer them –
a) Name this certain value of ‘i ’. What is the value of ‘r’ at that time ?
b) Name this process of returning of light in dense medium. Explain the process.
Total internal reflection can take place only if ______.
Solve the previous problem if the paperweight is inverted at its place so that the spherical surface touches the paper.
(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.
In the following figure, show two rays A and B travelling from water to air. If the critical angle for water- air surface is 48°, complete the ray diagram showing the refracted rays for each. State conditions when the ray will suffer total internal reflection.
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
If a ray of light passes from medium I to medium II without any change of direction, what can be said about the refractive indices of these media (angle I is not 0)?
State one factor on which a critical angle for a given pair of media depends. The critical angle for the glass-air interface is 45° for the yellow light. Will it be equal to, less than or greater than 45° for (i) red light, (ii) blue light?
Observe the given figure and write appropriate phenomenon of light in the box.
A green light is incident from the water to the air-water interface at the critical angle (C). Select the correct statement.
For total internal reflection to take place, the angle of inddence i and the refractive index µ of the medium must satisfy the inequality ____________.
The angle of minimum deviation produced by a thin glass prism in air is 'δ'. If that prism is immersed in water, the angle of minimum deviation will be ______.
( aμg = refractive index of glass w.r.t, air aμw = refractive index of water w.r.t. air)
Optical fibre communication uses the principle of ______.
A bundle of glass threads, each of which is capable of transmitting messages using light waves is called ______.
Observe the given figure of the raindrop and answer the following questions:
- Label A and B of the given diagram. Why colour will deviate most.
- Name the phenomenon shown in label C.
A given ray of light suffers minimum deviation in an equilateral prism P. Additional prism Q and R of identical shape and of the same material as P are now added as shown in the figure. The ray will now suffer ______.
Find the value of θ in the given figure.
