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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?
- Do you think that the students’ conclusion is correct?
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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.
- Yes, the student’s conclusion about the longer duration of the day because of atmospheric refraction is correct. Atmospheric refraction causes the sun to appear two minutes before the actual sunrise and two minutes after sunset. Therefore, the time from sunrise to sunset is increased by about four minutes. Thus, the day gets longer by about four minutes than if the earth had no atmosphere.
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संबंधित प्रश्न
What is atmospheric refraction? Use this phenomenon to explain the following natural events:
Advanced sun-rise and delayed sun-set.
Draw diagrams to illustrate your answers.
Name the phenomenon which causes the twinkling of stars.
Atmospheric refraction causes advance sunrise and delayed sunset. By how much time is:
sunrise advanced?
Atmospheric refraction causes advance sunrise and delayed sunset. By how much time is:
sunset delayed?
State whether the following statement is true or false:
The planets twinkle at night due to atmospheric refraction of light.
Why do stars seem higher than they actually are? Illustrate your answer with the help of a diagram.
What is atmospheric refraction?
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
The day is longer on the earth by about 4 minutes because:
(a) the earth is round in shape
(b) the earth rotates on its axis
(c) the earth revolves around the sun
(d) the earth has atmosphere
We know that light refracts (or bends) when it goes from one medium to another. Now, the atmosphere contains only air. Then how does light get refracted on passing through only air in the atmosphere?
By how much time the day would have been shorter if the earth had no atmosphere?
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.
Do you think that the students conclusion is correct?
The stars appear higher from horizon than they actually are. Explain why it is so.
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?
