
In which year the SI system of units was developed and recommended by the general conference on weights and measures?
A) \[1951\]
B) \[1961\]
C) \[1971\]
D) \[1981\]
Answer
150k+ views
Hint:SI unit is an abbreviation of the French word System International. The International System of Units (SI) is the metric system that is universally accepted as a standard for measurements.
Complete step by step solution:
The SI system of units was developed and recommended by the General Conference on Weights and Measures in\[1971\].
SI units have an important contribution in scientific and technological research and development. It comprises \[7\] base units which are used for defining \[22\] derived units.
The basic \[7\] fundamental units for fundamental quantities are as following,
Physical Quantities
S.I. Unit
For Mass is Kilogram (\[kg\])
For Length is Meter (\[m\])
For Time is Second (\[s\])
For Electric current is Ampere (\[A\])
For Temperature is Kelvin (\[K\])
For Amount of substance is Mole (\[mol\])
For Luminous intensity is Candela (\[cd\])
Unit of length, meter (\[m\]): Meter is the SI unit of length and is defined by taking the fixed value of the speed of light in vacuum. It is expressed as \[m{{s}^{-1}}\].
Unit of mass, kilogram (\[kg\]): Kilogram is the SI unit of mass and is defined by taking the fixed value of the Planck constant. It is expressed as \[kg{{m}^{2}}.{{s}^{-1}}\].
Unit of time, second (\[s\]): Second is the SI unit of time and is defined by taking the fixed value of Cesium frequency. It is expressed as \[{{s}^{1}}\].
Unit of electric current, ampere (\[A\]): Ampere is the SI unit of electric current and is defined by taking the fixed value of the elementary charge.
Unit of thermodynamic temperature, Kelvin (\[K\]): Kelvin is the SI unit of thermodynamic temperature and is defined by taking the fixed value of Boltzmann constant \[k=1.380649\times {{10}^{-23}}\].
Unit of the amount of substance, mole (\[mol\]): Mole is the SI unit of amount of substance and is defined by the fixed value of Avogadro constant \[{{N}_{A}}\]. One mole contains \[6.02214076\times {{10}^{23}}\] elementary entities and is expressed as \[mo{{l}^{-1}}\].
Unit of luminous intensity, candela (\[cd\]): Candela is the SI unit of luminous intensity and is defined by the fixed value of the luminous efficacy.
Note: The fundamental units are independent of any other units including themselves.
There are a total of seven fundamental units in the SI unit system.
The derived units are those units which are obtained by mathematical operations of fundamental units.
Complete step by step solution:
The SI system of units was developed and recommended by the General Conference on Weights and Measures in\[1971\].
SI units have an important contribution in scientific and technological research and development. It comprises \[7\] base units which are used for defining \[22\] derived units.
The basic \[7\] fundamental units for fundamental quantities are as following,
Physical Quantities
S.I. Unit
For Mass is Kilogram (\[kg\])
For Length is Meter (\[m\])
For Time is Second (\[s\])
For Electric current is Ampere (\[A\])
For Temperature is Kelvin (\[K\])
For Amount of substance is Mole (\[mol\])
For Luminous intensity is Candela (\[cd\])
Unit of length, meter (\[m\]): Meter is the SI unit of length and is defined by taking the fixed value of the speed of light in vacuum. It is expressed as \[m{{s}^{-1}}\].
Unit of mass, kilogram (\[kg\]): Kilogram is the SI unit of mass and is defined by taking the fixed value of the Planck constant. It is expressed as \[kg{{m}^{2}}.{{s}^{-1}}\].
Unit of time, second (\[s\]): Second is the SI unit of time and is defined by taking the fixed value of Cesium frequency. It is expressed as \[{{s}^{1}}\].
Unit of electric current, ampere (\[A\]): Ampere is the SI unit of electric current and is defined by taking the fixed value of the elementary charge.
Unit of thermodynamic temperature, Kelvin (\[K\]): Kelvin is the SI unit of thermodynamic temperature and is defined by taking the fixed value of Boltzmann constant \[k=1.380649\times {{10}^{-23}}\].
Unit of the amount of substance, mole (\[mol\]): Mole is the SI unit of amount of substance and is defined by the fixed value of Avogadro constant \[{{N}_{A}}\]. One mole contains \[6.02214076\times {{10}^{23}}\] elementary entities and is expressed as \[mo{{l}^{-1}}\].
Unit of luminous intensity, candela (\[cd\]): Candela is the SI unit of luminous intensity and is defined by the fixed value of the luminous efficacy.
Note: The fundamental units are independent of any other units including themselves.
There are a total of seven fundamental units in the SI unit system.
The derived units are those units which are obtained by mathematical operations of fundamental units.
Recently Updated Pages
Difference Between Circuit Switching and Packet Switching

Difference Between Mass and Weight

JEE Main Participating Colleges 2024 - A Complete List of Top Colleges

JEE Main Maths Paper Pattern 2025 – Marking, Sections & Tips

Sign up for JEE Main 2025 Live Classes - Vedantu

JEE Main 2025 Helpline Numbers - Center Contact, Phone Number, Address

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility, & More

JEE Main 2025: Derivation of Equation of Trajectory in Physics

Learn About Angle Of Deviation In Prism: JEE Main Physics 2025

Electric Field Due to Uniformly Charged Ring for JEE Main 2025 - Formula and Derivation

Degree of Dissociation and Its Formula With Solved Example for JEE

Electrical Field of Charged Spherical Shell - JEE

Other Pages
JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

Motion in a Straight Line Class 11 Notes: CBSE Physics Chapter 2

Units and Measurements Class 11 Notes: CBSE Physics Chapter 1

JEE Advanced 2025: Dates, Registration, Syllabus, Eligibility Criteria and More

NCERT Solutions for Class 11 Physics Chapter 1 Units and Measurements

JEE Advanced Weightage 2025 Chapter-Wise for Physics, Maths and Chemistry
