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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
A ray of light travels from water to air as shown in the diagram given below :
1) Copy the diagram and complete the path of the way. Given the critical angle for water is 48°.
2) State the condition so that internal reflection occurs in the above diagram.
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.
In the given figure PQ and PR are the two light rays emerging from an object P. The ray PQ is refracted as QS.
- State the special name given to the angle of incidence ∠PQN of the ray PQ.
- What is the angle of refraction for the refracted ray QS?
- Name the phenomenon that occurs if the angle of incidence ∠PQN is increased.
- The ray PR suffers partial reflection and refraction on the water-air surface. Give reason.
- Draw in the diagram the refracted ray for the incident ray PR and hence show the position of image of the object P by the letter P’ when seen vertically from above.
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.
Write the necessary conditions for the phenomenon of total internal reflection to
occur ?
One day Chetan’s mother developed a severe stomach ache all of a sudden. She was rushed to the doctor who suggested for an immediate endoscopy test and gave an estimate of expenditure for the same. Chetan immediately contacted his class teacher and shared the information with her. The class teacher arranged for the money and rushed to the hospital. On realizing that Chetan belonged to a below average income group family, even the doctor offered concession for the test fee. The test was conducted successfully.
Answer the following questions based on the above information:
(a) Which principle in optics is made use of in endoscopy?
(b) Briefly explain the values reflected in the action taken by the teacher.
(c) In what way do you appreciate the response of the doctor on the given situation?
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.
(i) Define critical angle.
(ii) State one important factor which affects the critical angle of a given medium.
(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?
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.
Images formed by totally reflecting prisms are brighter than the image formed by ordinary reflected light, why?
What is meant by the term ‘critical angle’?
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.
Under what conditions are total internal reflection possible? Explain it with a suitable example.
Answer the following question.
Why is prism binoculars preferred over traditional binoculars? Describe its working in brief.
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 ______.
The outer concentric shell in optic fiber is called ______.
Optical Fibres are based on the phenomenon of dispersion.
The angle of incidence at which the angle of refraction is Q£ is called the critical angle.
What is a mirage? How does it occur?
A green light is incident from the water to the air-water interface at the critical angle (θ). Select the correct statement.
The angle made by incident ray of light with normal of the reflecting surface is called ______.
Name any two phenomena which take place in the formation of a rainbow.
When a ray of light is refracted from one medium to another, then the wavelength changes from 6000 Å to 4000 Å. The critical angle for the interface will be ______.
