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प्रश्न
Give a scientific reason:
Danger signal lights are red in colour.
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उत्तर
- The effectiveness of scattering depends on the size of the particles and the wavelength of the light.
- Red light has the longest wavelength in the visible spectrum; therefore, it is scattered the least by air molecules, fog, or smoke.
- Due to minimal scattering, red light travels longer distances without losing its intensity and can be clearly seen from far away.
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संबंधित प्रश्न
Fill in the blank:
Very fine particles mainly scatter ………… colored light.
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Show with the help of a diagram, how unpolarised light from Sun gets linearly polarised by scattering.
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| Case study: Mirage in deserts |
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To a distant observer, the light appears to be coming from somewhere below the ground. The observer naturally assumes that light is being reflected from the ground, say, by a pool of water near the tall object. Such inverted images of distant tall objects cause an optical illusion to the observer. This phenomenon is called mirage. This type of mirage is especially common in hot deserts. Based on the above facts, answer the following question : |
A diver at a depth 12 m inside water `(a_(µω) = 4/3)` sees the sky in a cone of semi-vertical angle
A passenger in an aeroplane shall ______.
Between the primary and secondary rainbows, there is a dark band known as Alexandar’s dark band. This is because ______.
- light scattered into this region interfere destructively.
- there is no light scattered into this region.
- light is absorbed in this region.
- angle made at the eye by the scattered rays with respect to the incident light of the sun lies between approximately 42° and 50°.
