Mensuration formulas
MENSURATION FORMULAS
Colourful world
COLOURFUL WORLD Rainbow Formation:- It is a natural spectrum appearing in the sky after a rain shower. A rainbow is always formed in a direction opposite to that of the Sun. Three phenomena which are involved in rainbow formation are:- refraction dispersion and total internal reflection Atmospheric Refraction:- The refraction of sunlight by different layers of atmosphere is called atmospheric refraction. Phenomena caused by atmospheric refraction:- Apparent position of star :- The refractive index of earth’s atmosphere increases from top to bottom. So, the light coming from a star near the horizon has to travel from rarer to denser medium & it bends towards the normal. As a result the star appears higher than its actual position. Twinkling of stars:- Since the physical conditions of the earth’s atmosphere are not constant, so the light from stars appears to come from different directions. This results in fluctuation of apparent position of star. Als...
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