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प्रश्न
The boy walks towards the mirror at a speed of 1 m/s. At what speed does his image approach him?
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उत्तर
The image approaches him at a speed of 2 m/s . The reason being, the image moves at a speed of 1 m/s and
the relative speed of the image will be equal to the sum of the speeds of the image and the boy.
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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 |
What type of reflection of light takes place from a cinema screen?
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 angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
A man sits in an optician's chair looking into plane mirror which is 2 m away from him and views the image of a chart which faces the mirror and is 50 cm behind his head. How far away from his eyes does the chart appear to be?
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
Which phenomenon of light makes the water to appear shallower than it really is?
Show the lateral displacement of the ray on the diagram.
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
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.
What is the cause of refraction of light when it passes from one medium to another?
A ray of light A incident from air suffers partial reflection and refraction at the boundary of water.
- Complete the diagram showing (i) the reflected ray B and (ii) the refracted ray C.
- How are the angles of incidence i and refraction r related?
A small air bubble in a glass block when seen from above appears to be raised because of ______.
Write scientific reason.
A pencil appears to be broken near the surface of water.
Explain with diagrams how refraction of incident light takes place from
- rarer to denser medium
- denser to rarer medium
- normal to the surface separating the two media.
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 travels fastest in a vacuum. Why?
Light is refracted or bent while going from one medium to another because of its ______ changes.
Why a pencil partly immersed in water appears to be bent at the water surface.
How do twinkling stars occur? (or) what is the cause of the twinkling of stars?
