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प्रश्न
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is _______ nm.
विकल्प
400
500
600
700
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उत्तर
Lights of different colours are used as signal for safety transport. From these, the wavelength of red light is 700 nm.
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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 |
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?
What is the difference between regular reflection of light and diffuse reflection of light?
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 angle of reflection is equal to the angle of incidence:
(a) always
(b) sometimes
(c) under special conditions
(d) never
Explain how to read the following message which was found on some blotting paper:
A ray of light travelling in glass emerges into air. State whether it will bend towards the normal or away from the normal.
When a ray of light passes from air into glass, is the angle of refraction greater than or less than the angle of incidence?
As light rays pass from water into glass, are they refracted towards the normal or away from the normal?
Fill in the following blank with suitable word:
Light bends when is passes from water into air. We say that it 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?
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.
With the help of a diagram, show how when light falls obliquely on the side of a rectangular glass slab, the emergent ray is parallel to the incident ray.
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 .......... than air.
What do you understand by refraction of light?
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?
List in proper sequence the steps of the experiment for determining the approximate focal length of a given concave mirror by obtaining the image of a distant object.
The phenomenon of change in the direction of light when it passes from one transparent medium to another is called ___________.
The laws of reflection hold true for ______.
The incident rays and refracting rays are on opposite sides of the normal.
The refractive index of a transparent medium is always greater than ______.
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?
The bending of light as it passes from one medium to another is called ______.
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?
How do twinkling stars occur? (or) what is the cause of the twinkling of stars?
In refraction of light through a glass slab, the directions of the incident ray and the refracted ray are ______.
