Advertisements
Advertisements
प्रश्न
Explain why the planets do not twinkle but the stars twinkle.
उत्तर
The planets being closer to the Earth do not appear as point sources of light. The planet covers a small circular area in space, when viewed from Earth. So, even if light from one point in the circular disc is blocked, light from other points reaches our eyes. As the light from the planets are not completely blocked from our sight and they do not twinkle. Stars on the other hand are point sized objects and twinkle by atmospheric refraction of light.
APPEARS IN
संबंधित प्रश्न
What is atmospheric refraction? Use this phenomenon to explain the following natural events:
Twinkling of stars
Draw diagrams to illustrate your answers.
Atmospheric refraction causes advance sunrise and delayed sunset. By how much time is:
sunset delayed?
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
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?
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.
Explain the refraction of light through a triangular glass prism using a labelled ray diagram. Hence define the angle of deviation.
How does refraction take place in the atmosphere? Why do stars twinkle but not the planets?
