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प्रश्न
What is refraction of light?
What is refraction of light? Explain with the help of example.
उत्तर
- Light changes its direction when going from one transparent medium to another transparent medium. This is called the refraction of light.
- e.g. The coin disappears in a vessel as it is seen from a specific location. But as soon as the water is poured into the vessel to a certain level, the coin appears. This 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
| 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 |
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?
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
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?
With the help of a labelled ray-diagram, describe how a plane mirror forms an image of a point source of light placed in front of it. State the characteristics of the image formed 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?
If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?
State two effects caused by the refraction of light.
A ray of light passes from air into a block of glass. Does it bend towards the normal or away from it?
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?
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.
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.
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 ray of light passes from a medium X to another medium Y. No refraction of light occurs if the ray of light hits the boundary of medium Y at an angle of:
(a) 0°
(b) 45°
(c) 90°
(d) 120°
Water is optically denser than glass.
Draw a diagram showing the refraction of a light ray from water to glass. Label on it the incident ray, the angle of incidence (/), and the angle of refraction (r)
Draw suitable diagrams to illustrate how a beam of light incident parallel to the principal axis is reflected by:
(a) a concave mirror, and (b) a convex mirror
The diagram (figure) given below shows two parallel rays 1 and 2 incident on (a) a concave mirror, (b) a convex mirror. Draw the reflected rays and mark the focus by the symbol F.
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.
Explain how the formation of a rainbow occurs.
The laws of reflection hold true for:
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is _______ nm.
The speed of light varies in different media.
Why does a ray of light bend when it travels from one medium to another?
The refractive index of a transparent medium is always greater than ______.
The deviation of light ray from its path when it travels from one transparent medium to another transparent medium is called ______.
If a beam of red light and a beam of violet light are incident at the same angle on the inclined surface of a prism from air medium and produce angles of refraction r and v respectively, which of the following is correct?
How does the light travel?
Light is refracted or bent while going from one medium to another because of its ______ changes.
Assertion: The air bubble shines in water.
Reason: Air bubble shines due to the refraction of light.
Under what circumstances there won’t be any refraction of light when it enters from one medium to another?
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 |
When a ray of light travels normal to the given surface, then the angle of refraction is ______.
