GK
THE UNIVERSE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The critical mass-energy density is the mass-energy density required for a ____
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flat universe.
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closed universe.
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open universe.
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None of the above
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Explanation:
Detailed explanation-1: -The ‘critical density ‘ is the average density of matter required for the Universe to just halt its expansion, but only after an infinite time. A Universe with the critical density is said to be flat.
Detailed explanation-2: -The expansion rate we see today indicates that the critical density of the Universe is about 9×10-27 kg m-3. This density, however, is the total density of both matter and energy.
Detailed explanation-3: -Since the critical density is 140 billion solar masses per cubic Mpc, the mass-to-luminosity ratio of the Universe needs to be 700 solar if the Universe has the critical density.
There is 1 question to complete.