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प्रश्न
A student claims that because of atmospheric refraction, the sun can be seen after it has set, and the day is, therefore, longer than if the earth had no atmosphere.
What does the student mean by saying that the sun can be seen after it has set?
उत्तर
The refraction of sunlight by the earth's atmosphere causes the sun to be seen for about two minutes even after it has set below the horizon.
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संबंधित प्रश्न
State whether the following statement is true or false:
The planets twinkle at night due to atmospheric refraction of light.
The twinkling of stars is due to atmospheric:
(a) reflection of light
(b) dispersion of light
(c) interference of light
(d) refraction of light
The stars appear higher in the sky than they actually are, due to:
(a) diffraction of light
(b) scattering of light
(c) refraction of light
(d) reflection of light
The stars twinkle but the planets do not twinkle at night because:
(a) the stars are small but the planets are large
(b) the stars are very large but planets are small
(c) the stars are much nearer but planets are far off
(d) the stars are far off but planets are nearer to earth
State two effects produced by the scattering of light by the atmosphere.
A star sometimes appears brighter and some other times fainter. What is this effect called? State the reason for this effect.
The air layer of the atmosphere whose temperature is less than the hot layer behave as optically:
Refraction of light by the earth’s atmosphere due to variation in air density is called ____________.
Assertion: Sky appears blue in the day time.
Reason: White light is composed of seven colours.
How does refraction take place in the atmosphere? Why do stars twinkle but not the planets?