GK
PHYSICS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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1 day
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1 hour
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1 minute
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1 second
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Detailed explanation-1: -The second is defined by taking the fixed numerical value of the cesium frequency ∆Cs, the unperturbed ground-state hyperfine transition frequency of the cesium-133 atom, to be 9, 192, 631, 770 when expressed in the unit Hz, which is equal to s−1.
Detailed explanation-2: -The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency Cs, the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s–1.
Detailed explanation-3: -The base unit of time in the International System of Units (SI) and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom.
Detailed explanation-4: -The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as 1⁄86400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400).