GK
THE UNIVERSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Which statement is correct?
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The red shift was discovered by Edward Hubble
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The red shift measures the distance of stars or galaxies through the use of wavelengths
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The red shift is an evidence that the universe is static and unchanging
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The red shift does not apply in the expanding universe
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Explanation:
Detailed explanation-1: -’Red shift’ is a key concept for astronomers. The term can be understood literally-the wavelength of the light is stretched, so the light is seen as ‘shifted’ towards the red part of the spectrum. Something similar happens to sound waves when a source of sound moves relative to an observer.
Detailed explanation-2: -To determine the distance to a galaxy one would only need to measure its apparent (angular) size, and use the small angle equation: a = s / d, where a is the measured angular size (in radians!), s is the galaxy’s true size (diameter), and d is the distance to the galaxy.
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