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प्रश्न
| Column I | Column II | Column III | |
| 1 | Dispersion | Long-sightedness | Twinkling of stars |
| 2 | Refraction | Splitting of white light into component colours | Convex lens |
| 3 | Hypermetropia | Change in the direction of the ray of light due to change in medium | Spectrum of seven colours |
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उत्तर
| Column I | Column II | Column III | |
| 1 | Dispersion | Splitting of white light into component colours | Spectrum of seven colours |
| 2 | Refraction | Change in the direction of the ray of light due to change in medium | Twinkling of stars |
| 3 | Hypermetropia | Long-sightedness | Convex lens |
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संबंधित प्रश्न
Name the phenomenon responsible for the following effect:
When we sit in front of a plane mirror and write with our right hand, if appears in the mirror that we are writing with the left hand.
State whether the following statement is true of false:
A student says that we can see an object because light from our eyes is reflected back by the object.
Where is the image when you look at something in a mirror?
Which type of reflection of light leads to the formation of images?
Define the following terms used in the study of reflection of light by drawing a labelled ray-diagram:
(a) Incident ray
(b) Point of incidence
(c) Normal
(d) Reflected ray
(e) Angle of incidence
(f) Angle of reflection
Explain why, though both a plane mirror and a sheet of paper reflect light but we can see the image of our face in a plane mirror but not in a sheet of paper.
Write all the capital letters of the alphabet which look the same in a plane mirror.
A man stands 10 m in front of a large plane mirror. How far must the walk before he is 5 m away from his image?
Name the phenomenon due to which a swimming pool appears less deep than it really is.
A ray of light passes from air into a block of glass. Does it bend towards the normal or away from it?
Which phenomenon of light makes the water to appear shallower than it really is?
What is meant by 'refraction of light'? Draw a labelled ray diagram to show the refraction of light.
A ray of light travelling in air is incident on a rectangular glass block and emerges out into the air from the opposite face. Draw a labelled ray diagram to show the completer path of this ray of light. Mark the two points where the refraction of light takes place. What can you say about the final direction of ray of light?
Light travels more quickly through water than through glass.
Which is optically denser : water or glass?
A coin in a glass tumbler appears to rise as the glass tumbler is slowly filled with water. Name the phenomenon responsible for this effect.
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.
Show the lateral displacement of the ray on the diagram.
State two factors on which the lateral displacement of the emergent ray depends.
Light travelling from a denser medium to a rarer medium along a normal to the boundary:
(a) is refracted towards the normal
(b) is refracted away from the normal
(c) goes along the boundary
(d) is not refracted
A vertical ray of light strikes the horizontal surface of some water:
What is the angle of incidence?
Water is optically denser than glass.
The speed of light is more in glass than in water.
Water is optically .......... than air.
Fill in the blank and Explain the completed sentences.
The change in ______ of light rays while going from one medium to another is called refraction.
What is atmospheric reflection? Explain with the help of a labelled diagram that the position of a star as seen by us is not its true position.
The size of image of an object by a convex lens of focal length 20 cm is observed to be reduced to `1/3` rd of its size . Find the distance of the object from the optical centre of the lens .
Explain how the formation of a rainbow occurs.
Due to _______ pencil looks bent in water, in the given experiment.

Write scientific reason.
The sun appears on the western horizon for some time after sunset.
State whether true or false. If false, correct the statement.
The angle of deviation depends on the refractive index of the glass.
Numerical problems.
The speed of light in water is 2.25 × 108 ms–1. If the speed of light in vacuum is 3 × 108 ms–1, calculate the refractive index of water.
A pencil when dipped in water in a glass tumbler appears to be bent at the interface of air and water. Will the pencil appear to be bent to the same extent, if instead of water we use liquids like, kerosene or turpentine. Support your answer with reason.
Light bends as it passes from one medium to another. What is this phenomenon called?
Mirage is an example of refraction and the total internal reflection of light.
Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
