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Physics · UNITS AND MEASUREMENT
हिन्दीAccording to the SI base units definitions in Table 1.1, the second is defined in terms of which of the following?
Correct answer · Option 2
Caesium frequency \( \Delta \nu_{cs} \)
Explanation
The second is defined by taking the fixed numerical value of the caesium frequency \( \Delta \nu_{cs} \), the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom.
