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प्रश्न
Observe the following figure and answer the questions given under it:
1) How many times does refraction take place in the above figure?
2) What happens to the ray of light when it passes from air to glass?
3) What happens to the ray of light when it passes from glass to air?
4) What are the rays AB and CD in the figure called?
5) Define refraction.
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उत्तर
An expression for heat produced in a conductor by using Joule's experiment:
1) Refraction occurs twice, once at Point N and the second time at Point M.
2) Air is rarer than glass. So, when light passes from the rarer medium to the denser medium, it bends towards the normal.
3) When light passes from the denser (glass) medium to the rarer (air) medium, it bends away from the normal.
4) Ray AB is called the incident ray, and ray CD is called the emergent ray.
5) Refraction of light is the phenomenon of change in the direction of propagation of light when it passes obliquely from one transparent medium to another.
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संबंधित प्रश्न
Choose the correct alternative and rewrite the following sentence.
A ray of light strikes the glass slab at an angle of 50°. What is the angle of incidence?
Define refraction and state the laws of refraction.
Explain how the formation of a rainbow occurs.
Study the following four experimental set-ups I, II, III and IV for the experiment, "To trace the path of a ray of light through a rectangular glass slab."
Which of the marked set-ups is likely to give best results (P1 and P2 are the positions of pins fixed on the incident ray)?
(A) I
(B) II
(C) III
(D) IV
On the basis of the experiment, "To trace the path of a ray of light through a rectangular glass slab", students of a class arrived at which one of the following conclusions?
(A) Angle of incidence is greater than the angle of emergence.
(B) Angle of emergence is smaller than the angle of refraction.
(C) Emergent ray is parallel to the refracted ray.
(D) Incident ray and emergent ray are parallel to each other.
A student very cautiously traces the path of a ray through a glass slab for different values of the angle of incidence (∠i). He then measures the corresponding values of the angle of refraction (∠r) and the angle of emergence (∠e) for every value of the angle of incidence. On analysing these measurements of angles, his conclusion would be
(A) ∠i > ∠r > ∠e
(B) ∠i = ∠e > ∠r
(C) ∠i < ∠r < ∠e
(D) ∠i = ∠e < ∠r
Why do we get a spectrum of seven colors when white light is dispersed by a prism?
Draw the diagram given below and clearly show the path taken by the emergent ray.
A ray of light passes from water to air. How does the speed of light change?
How is the reflection of light ray from a plane mirror different from the refraction of light ray as it enters a block of glass?
Write the relation between the angle of incidence and the angle of refraction for a medium.
Draw diagrams to show the refraction of light from glass to air. In diagram, label the incident ray, refracted ray, the angle of incidence (i) and the angle of refraction (r).
How is the refractive index of a medium related to the speed of light in it?
Light of a single colour is passed through a liquid having a piece of glass suspended in it. On changing the temperature of liquid, at a particular temperature the glass piece is not seen. When is the glass piece not seen?
When a ray of light from air enters a denser medium, it ______.
A ray of light of wavelength 6600 Å suffer refraction from air to glass. Taking \[\ce{_a\mu_g = \frac{3}{2}}\], find the wavelength of light in glass.
How does the speed of light change when it passes from glass to water?
What is meant by the statement the critical angle for diamond is 24°?
A ray of light enters a glass slab ABDC as shown in figure and strikes at the centre O of the circular part AC of the slab. The critical angle of glass is 42°. Complete the path of the ray till it emerges out from the slab. Mark the angles in the diagram wherever necessary.
A ray of light OP passes through a right angles prism as shown in the adjacent diagram.
(a) State the angles of incidence at the faces AC and BC.
(b) Name the phenomenon which the ray suffers at the face AC.
Which of the following is the best experimental set-up out of the four shown for tracing the path of a ray of light passing through a rectangular glass slab ?
“A ray of light incident on a rectangular glass slab immersed in any medium emerges parallel to itself.” Draw labelled ray diagram to justify the statement.
While tracing the path of a ray of light passing through a rectangular glass slab a student tabulated his observations as given below:
|
S.NO. |
∠i |
∠r |
∠e |
|
I |
60° |
40° |
61° |
|
II |
50° |
36° |
51° |
|
III |
40° |
28° |
39° |
|
IV |
30° |
20° |
31° |
The correct observations is:
(A) I
(B) II
(C) III
(D) IV
While performing the experiment on tracing the path of a ray of light through a rectangular glass slab, in which of the following experimental set-ups is a student likely to get best results? P1 and P2 are the positions of pins fixed by him.
(A) I
(B) II
(C) III
(D) IV
Fill in the blank to complete the following sentence:
When light travels from a rarer to a denser medium, it bends ...........
Draw a ray diagram showing the lateral displacement of a ray of light when it passes through a parallel sided glass slab.
A fish swimming in a pond seems nearer than it really is. Explain.
State the relation between the refractive index μ and the velocity of light (vm) in that medium.
You are provided with a printed piece of paper. Using this paper how will you differentiate between a convex lens and a concave lens?
Two parallel rays of Red and Violet travelling through the air, meet the air-glass boundary as shown in the above figure. Will their paths inside the glass be parallel? Give a reason for your answer.
How will you verify the laws of refraction or how the refractive index of glass is determined in the laboratory?
The diagram shows the path of a ray of light through a rectangular glass block placed in a liquid of uniform density.
What is the angular, deviation of the emergent ray from the glass block with respect to the incident ray?
Draw a diagram of a prism and label:
(i) the base,
(ii) the refracting surfaces,
(iii) the refracting edge,
(iv) the refracting angle in it.
Write the approximate values of speed of light in (i) air and (ii) glass. Use these values to calculate the refractive index of glass with respect to air.
The refractive index of glass with respect to air is 1.5. What is the value of the refractive index of air with respect to glass?
A ray of light is incident at an angle of 45° on one face of a rectangular glass slab of thickness 10 cm and refractive index 3/2. Calculate the lateral shift produced ______.
The diagram below shows two parallel rays A (Orange) & B (Blue) incident from air, on air-glass boundary.
- Copy and complete the path of the rays A and B.
- How do the speeds of these rays differ in glass?
- Are the two refracted rays in glass parallel? Give a reason.
