SSC MTS EXAM

Detailed explanation-1: -The kilogram (kg) is defined by taking the fixed numerical value of the Planck constant h to be 6.62607015 ×10−34 when expressed in the unit J s, which is equal to kg m2 s−1, where the meter and the second are defined in terms of c and ∆Cs.

Detailed explanation-2: -In summary: the kilogram became the base unit because it is coherent with the joule, which is derived from the practical units volt and ampere. Note that the kilogram being a base unit has nothing to do with the kilogram being the calibration artefact. This is shown by the example of the CGS unit system.

Detailed explanation-3: -The SI unit of mass is kilogram(kg).