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प्रश्न
What is refraction of light?
What is refraction of light? Explain with the help of an example.
Explain the refraction of light.
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उत्तर
- Light changes its direction when going from one transparent medium to another transparent medium. This change in direction is called the refraction of light.
- For example, the coin appears to disappear in a vessel when viewed from a specific angle. But as soon as the water is poured into the vessel at a certain level, the coin appears. This phenomenon is because light rays coming from the coin emerge out of the water and change their direction due to the refraction of light.
संबंधित प्रश्न
If an object is placed at a distance of 10 cm in from of a plane mirror, how far would it be from its image?
What is lateral inversion? Explain by giving a suitable example.
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.
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
State and explain the laws of reflection of light at a plane surface (like a plane mirror), With the help of a labelled ray-diagram. Mark the angles of 'incidence' and 'reflection' clearly on the diagram. If the angle of reflection is 47.5°, what will be the angle of incidence?
The image in a plane mirror is virtual and laterally inverted. What does this statement mean?
Write all the capital letters of the alphabet which look the same in a plane mirror.
The image of an object formed by a plane mirror is:
(a) virtual
(b) real
(c) diminished
(d) upside-down
A ray of light strikes a plane mirror PQ at an angle of incidence of 30°, is reflected from the plane mirror and then strikes a second plane mirror QR placed at right angles to the first mirror. The angle of reflection at the second mirror is ______.
If a ray of light goes form a denser medium to a rarer medium, will it bend towards the normal or away from the normal?
A ray of light travelling in glass emerges into air. State whether it will bend towards the normal or away from the normal.
Name the phenomenon due to which a swimming pool appears less deep than it really is.
As light rays pass from water into glass, are they refracted towards the normal or away from the normal?
In which material do you think light rays travel faster-glass or air?
Which phenomenon of light makes the water to appear shallower than it really is?
Fill in the following blank with suitable word:
Light travelling along a normal is ...............refracted.
What is meant by 'refraction of light'? Draw a labelled ray diagram to show the refraction of light.
When a light ray passes from air into glass, what happens to its speed? Draw a diagram to show which way the ray of light bends.
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.
Explain with the help of a labelled ray diagram, why a pencil partly immersed in water appears to be bent at the water surface. State whether the bending of pencil will increase or decrease if water is replaced by another liquid which is optically more dense than water. Give reason for your answer.
How does the light have to enter the glass:
to produce a large amount of bending?
Water is optically denser than glass.
The speed of light is more in glass than in water.
Water is optically .......... than air.
Air is optically .......... than glass.
When a ray of light travels from air to glass, it bends .......... the normal.
What do you understand by refraction of light?
What is the cause of refraction of light when it passes from one medium to another?
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 phenomenon of change in the direction of light when it passes from one transparent medium to another is called ___________.
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is _______ nm.
Identify the wrong figure from the following.
Write scientific reason.
The bottom of a pond appears raised.
Write scientific reason.
A pencil appears to be broken near the surface of water.
Explain the working of a periscope.
State whether true or false. If false, correct the statement.
The angle of deviation depends on the refractive index of the glass.
The refractive index of four substances A, B, C, and D are 1.31, 1.43, 1.33, 2.4 respectively. The speed of light is maximum in
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
In the above diagram light is travelling through different media. It is noted by a scientist that ∠1= ∠3 = ∠4 but ∠2 < ∠1. Which of the following statement would be correct?
When light passes from one medium to another the ray gets bent. This property of light is called ______.
A star appears twinkling into the sky because of the reflection of light by the atmosphere.
Why a pencil partly immersed in water appears to be bent at the water surface.
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 |
A ray of light starting from diamond is incident on the interface separating diamond and water. Draw a labelled ray diagram to show. the refraction of light in this case.
