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प्रश्न
A glass slab is placed over a page on which the word VIBGYOR is printed with each letter in its corresponding colour.
- Will the image of all the letters be in the same place?
- If not, the state which letter will be raised to the maximum. Give a reason for your answer.
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उत्तर
- The image of all the letters of the word VIBGYOR in their corresponding colours will not be at the same place.
- The letter of violet colour (i.e. V) appears to be raised maximum, while the letter of red colour (i.e. R) appears to be raised minimum.
Since apparent depth = `"real depth"/"refractive index"` and the refractive index of glass is most for the violet light while least for the red light, therefore the apparent depth is least for violet and most for the red.
संबंधित प्रश्न
Fig 4.31 below shows a light ray of single colour incident normally on two prisms A and B. In each case draw the path of the ray of light as it enters and emerges out of the prism. Mark the angle wherever necessary.
The refractive index of glass is 1.5. From a point P inside a glass block, draw rays PA, PB and PC incident on the glass air surface at an angle of incidence 30°, 42° and 60° respectively.
- In the diagram show the approximate direction of these rays as they emerge out of the block.
- What is the angle of refraction for the ray PB?
`("Take" sin 42° =2/3)`
A student traces the path of a ray of white light through a rectangular glass slab and marks, the angles of incidence (∠i) , refraction (∠r) and emergence (∠e) as shown. Which angle or angles has he not marked correctly?

(A) ∠i only
(B) ∠i and ∠r
(C) ∠i and ∠e
(D) ∠r and ∠e
What is the correct reason for blinking / flickering of stars? Explain it.
a) The blasts in the stars.
b) Absorption of star light by the atmosphere.
c) Motion of the stars.
d) Changing refractive index of gases in the atmosphere.
Draw a ray diagram showing the lateral displacement of a ray of light when it passes through a parallel sided glass slab.
What do you understand by the deviation produced by a prism?
You are provided with a printed piece of paper. Using this paper how will you differentiate between a convex lens and a concave lens?
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.

(a) Does the light speed up or slow down in the glass,
(b) Give the reason for your answer.
Trace a ray of light incident at 30° on a surface if travelling from glass to air. What is the angle of refraction in this case? (R.I. for glass = 3/2).
