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प्रश्न
The danger signal is red. Why?
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उत्तर
Since the wavelength of red light is the longest in the visible light, the light of red colour is scattered the least by the air molecules of the atmosphere and therefore the light of red colour can penetrate to a longer distance. Thus red light can be seen from the farthest distance as compared to other colours of same intensity. Hence it is used for danger signal so that the signal may be visible from the far distance.
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संबंधित प्रश्न
Name a natural phenomenon which is caused by the dispersion of sunlight in the sky.
What colours make up white light?
Which light has the longer wavelength : red light or blue light?
Which colour of light has the shorter wavelength − red or violet?
Why does the sun appear red at sunset?
Draw a neat and labelled diagram of the experimental set up for observing the scattering of light in a colloidal solution of sulphur to show how the sky appears blue, and the sun appears red at sunrise and sunset.
The blue colour of sky is due to:
(a) refraction of light
(b) dispersion of light
(c) diffraction of light
(d) scattering of light
Explain in brief the reason for the following:
Twinkling of stars
Is the position of a star as seen by us its true position? Justify your answer.
The colour of clear sky from the earth appears blue but from the space it appears black. Why?
