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The twinkling of stars is due to atmospheric:
(a) reflection of light
(b) dispersion of light
(c) interference of light
(d) refraction of light
Concept: undefined >> undefined
The atmospheric refraction of light causes the twinkling of:
(a) planets only
(b) stars only
(c) planets and stars
(d) stars and satellites
Concept: undefined >> undefined
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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
Concept: undefined >> undefined
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
Concept: undefined >> undefined
As light from a far off star comes down towards the earth:
(a) it bends away from the normal
(b) it bends towards the normal
(c) it does not bend at all
(d) it is reflected back
Concept: undefined >> undefined
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
Concept: undefined >> undefined
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
Concept: undefined >> undefined
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?
Concept: undefined >> undefined
By how much time the day would have been shorter if the earth had no atmosphere?
Concept: undefined >> undefined
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?
Concept: undefined >> undefined
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?
Concept: undefined >> undefined
State one effect produced by the scattering of light by the atmosphere.
Concept: undefined >> undefined
Why does the sky appear blue on a clear day?
Concept: undefined >> undefined
What causes the scattering of blue component of sunlight in the atmosphere?
Concept: undefined >> undefined
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
Concept: undefined >> undefined
A star sometimes appears brighter and some other times fainter. What is this effect called? State the reason for this effect.
Concept: undefined >> undefined
The stars appear higher from horizon than they actually are. Explain why it is so.
Concept: undefined >> undefined
Explain why the planets do not twinkle but the stars twinkle.
Concept: undefined >> undefined
The air layer of the atmosphere whose temperature is less than the hot layer behave as optically:
Concept: undefined >> undefined
Refraction of light by the earth’s atmosphere due to variation in air density is called ____________.
Concept: undefined >> undefined
