SSC MTS EXAM

Detailed explanation-1: -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-2: -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-3: -The seven SI base units, which are comprised of: Length-meter (m) Time-second (s) Amount of substance-mole (mole) Electric current-ampere (A)

Detailed explanation-4: -Although not an SI unit, the minute is accepted for use with SI units. The SI symbol for minute or minutes is min (without a dot). The prime symbol is also sometimes used informally to denote minutes of time.