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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
Which colour of the spectrum has
shortest wavelength?
We can see the sun before the actual sunrise by about:
(a) 5 minutes
(b) 2 minutes
(c) 2 hours
(d) 20 minutes
State whether the following statements are true or false:
The scattering away of red light makes the sky appear blue during the day time.
State whether the following statements are true or false:
The scattering away of blue light makes the sun appear red at sunset.
What colour does the sky appear to an astronaut?
In an experiment to study the scattering of light by passing a beam of white light through a colloidal solution of sulphur in a transparent glass tank:
Which colour is observed from the front of the glass tank? Does this colour correspond to the colour of sky on a clear day or the colour of sky around the sun at sunset?
In an experiment to study the scattering of light by passing a beam of white light through a colloidal solution of sulphur in a transparent glass tank:
Which colour is observed from the sides of the glass tank? Does this colour correspond to the colour of sky on a clear day or the colour of sky around the sun at sunset?
A beam of blue, green, and yellow light passes through the earth's atmosphere. Name the colour which is scattered the least.
Draw a labelled diagram to show (i) reddish appearance of the sun at the sunrise or the sunset and (ii) white appearance of the sun at noon when it is overhead.
The clear sky appears blue because
