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प्रश्न
Choose the correct option.
Select the WRONG statement.
विकल्प
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.
What do you understand by the deviation produced by a prism? Why is it caused?
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.
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?
Calculate the speed of light in a medium whose critical angle is 30° ?
(i) Define critical angle.
(ii) State one important factor which affects the critical angle of a given medium.
Plot a graph between
Sine of angle of incidence versus sine of 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?
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.
How does a ray of light bend when it travels from denser to rarer medium.
How does a ray of light bend when it travels from when it is normal to the interface of the two media.
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.
A ray of light incident at an angle of incidence ‘i’ passes through an equilateral glass prism such that the refracted ray inside the prism is parallel to its base and emerges from the prism at an angle of emergence ‘e’.
How is the angle of emergence ‘e’ related to the angle of incidence ‘i’?
What is meant by the statement, ‘the critical angle for diamond is 24°’?
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.
Answer the following question.
Define the critical angle of incidence and obtain an expression for it.
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?
Which of the following statements about total internal reflection is true?
The critical angle is defined as the angle of incidence at which the total internal reflection starts to occur.
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?
What is the phenomenon used in optical fiber? Explain.
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 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 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 ______.
State two differences between normal reflection and total internal reflection.
