Question

1.Why was it essential to adopt SI system in the field of measurement when there were already some international standard systems like FPS, CGS, and MKS
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Answer 1

Explanation:

The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system. It is the only system of measurement with an official status in nearly every country in the world. It comprises a coherent system of units of measurement starting with seven base units, which are the second (the unit of time with the symbol s), metre (length, m), kilogram (mass, kg), ampere (electric current, A), kelvin (thermodynamic temperature, K), mole (amount of substance, mol), and candela (luminous intensity, cd). The system allows for an unlimited number of additional units, called derived units, which can always be represented as products of powers of the base units.[Note 1] Twenty-two derived units have been provided with special names and symbols.[Note 2] The seven base units and the 22 derived units with special names and symbols may be used in combination to express other derived units,[Note 3] which are adopted to facilitate measurement of diverse quantities. The SI system also provides twenty prefixes to the unit names and unit symbols that may be used when specifying power-of-ten (i.e. decimal) multiples and sub-multiples of SI units. The SI is intended to be an evolving system; units and prefixes are created and unit definitions are modified through international agreement as the technology of measurement progresses and the precision of measurements improves.

Symbol

Name

Quantity

s

second

time

m

metre

length

kg

kilogram

mass

A

ampere

electric current

K

kelvin

thermodynamic temperature

mol

mole

amount of substance

cd

candela

luminous intensity

SI defining constants

Symbol

Name

Exact value

{\displaystyle \Delta \nu _{\text{Cs}}}{\displaystyle \Delta \nu _{\text{Cs}}}

hyperfine transition frequency of Cs

9192631770 Hz

c

speed of light

299792458 m/s

h

Planck constant

6.62607015×10−34 J⋅s

e

elementary charge

1.602176634×10−19 C

k

Boltzmann constant

1.380649×10−23 J/K

NA

Avogadro constant

6.02214076×1023 mol−1

Kcd

luminous efficacy of 540 THz radiation

683 lm/W

Answer 2

Answer:

Because to measure the quantities unit are specialised....

Explanation:

Hope it helps you dear....