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प्रश्न
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?
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उत्तर
We know that light refracts when it travels from one medium to another. Though the earth's atmosphere contains only air, refraction takes place because the atmosphere consists of layers of air that are at different temperatures. The layers of air that are hotter behave like an optically rarer medium and those that are cooler behave like an optically denser medium. Therefore, when light travels through these layers of air of different optical densities, bending of light, or refraction, takes place.
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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.
Explain why the planets do not twinkle.
Name two effects produced by the atmospheric refraction.
Atmospheric refraction causes advance sunrise and delayed sunset. By how much time is:
sunrise advanced?
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
Due to atmospheric refraction of sunlight, the time from sunrise to sunset is lengthened by about:
(a) 6 minutes
(b) 2 minutes
(c) 4 minutes
(d) 5 minutes
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
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.
- 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?
What causes the scattering of blue component of sunlight in the atmosphere?
Which of the following is not caused by the atmospheric refraction of light?
(a) twinkling of stars at night
(b) sun appearing higher in the sky than it actually is
(c) sun becoming visible two minutes before actual sunrise
(d) sun appearing red at sunset
Assertion: Sky appears blue in the day time.
Reason: White light is composed of seven colours.
