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प्रश्न
Write scientific reason.
A pencil appears to be broken near the surface of water.
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उत्तर
- When one look at the portion of the pencil that is inside the water, light travels from water to air via glass.
- This light ray changes the medium and undergoes refraction.
- As a result, the pencil inside the water appears to be broken near the surface of water.
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संबंधित प्रश्न
Name the phenomenon responsible for the following effect:
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Which property of light makes a pencil cast a shadow when it is held in front of a light source?
Where is the image when you look at something in a mirror?
A ray of light strikes a plane mirror such that its angle of incidence is 30°. What angle does the reflected ray make with the mirror surface?
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What type of reflection of light takes place from a cinema screen?
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
An extended object in the form of an arrow pointing upward has been placed in front of a plane mirror. Draw a labelled ray-diagram to show the formation of its image.
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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.
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(a) virtual
(b) real
(c) diminished
(d) upside-down
If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?
A ray of light goes from water into air. Will it bend towards the normal or away from the normal?
Name the phenomenon due to which a pencil partly immersed in water and held obliquely appears to be bent at the water surface.
A vertical ray of light strikes the horizontal surface of some water:
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- What is the angle of refraction?
How does the light have to enter the glass:
for no refraction to happen?
The depth of a pond when seen from above appears to be less.
When a ray of light travels from air to glass, it bends .......... the normal.
What do you understand by refraction of light?
We can see the sun even when it is little below the horizon because of ______.
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 .
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Right or wrong sentence.
The incident rays and refracted rays are on opposite sides of the column.
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State whether true or false. If false, correct the statement.
The angle of deviation depends on the refractive index of the glass.
Why does a ray of light bend when it travels from one medium to another?
Assertion and reasoning type
- Assertion: If the refractive index of the medium is high (denser medium) the velocity of the light in that medium will be small
- Reason: Refractive index of the medium is inversely proportional to the velocity of the light
The deviation of light ray from its path when it travels from one transparent medium to another transparent medium is called ______.
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Which object use the reflection of light?
Light is refracted or bent while going from one medium to another because of its ______ changes.
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Which is optically denser out of the two medium M1& M2 having the refractive indices = 1.71 and 1.36 respectively?
Match the following:
| Column I | Column II | ||
| 1. | r > 90 | a. | Light gazes at the surface of separation between the two modes. |
| 2. | r = 90 | b. | No refraction. |
| 3. | r < 90 | c. | Refracted ray away from the normal |
