श्रेणी:SI मूल इकाइयाँ
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|मीटर||m||लम्बाई||लम्बाई की इकाई बरबर है: प्रकाश द्वारा वनिर्वात में एक सैकिण्ड के 1⁄299,792,458वें भाग में तय की गयी दूरी के।
बराबर 100 cm (लगभग 39.37 इंच)
परिभाषित: 17वीं CGPM (1983) रिजॉ़ल्यूशन 1, CR 97
|पृथ्वी की भूमध्य रेखा से उत्तरी ध्रुव की पैरिस से होते हुए न्यूनतम दूरी का 1⁄10,000,000वां भाग।|
|किलोग्राम||kg||भार||The unit of mass is equal to the mass of the international prototype kilogram (a platinum-iridium cylinder) kept at the Bureau International des Poids et Mesures (BIPM), Sèvres, Paris (1st CGPM (1889), CR 34-38). Note that the kilogram is the only base unit with a prefix. See the kilogram article for an alternative definition.||The mass of one litre of water. Kilogram was originally named "grave" and symbolized G. The gram is defined as a derived unit, equal to 1⁄1000 of a kilogram; prefixes such as mega are applied to the gram, not the kg; e.g. Gg, not Mkg. It is also the only unit still defined by a physical prototype instead of a measurable natural phenomenon.|
|सैकिण्ड||s||समय||The unit of time is the duration of exactly 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium-133 atom at a temperature of 0 K.
Defined by: 13th CGPM (1967-1968) Resolution 1, CR 103
|The day is divided in 24 hours, each hour divided in 60 minutes, each minute divided in 60 seconds.|
A second is 1⁄24 × 60 × 60 of the day
|एम्पीयर||A||विद्युत धारा||The ampere is the unit of electric current. The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2 × 10–7 newton per metre of length.|
|कैल्विन||K||तापमान||The unit of thermodynamic temperature (or absolute temperature) is the fraction 1⁄273.16 (exactly) of the thermodynamic temperature at the triple point of water.
Defined by: 13th CGPM (1967) Resolution 4, CR 104
|Historically, the Celsius scale was used before the kelvin. 1 degree Celsius (or degree centigrade) = 1⁄100 of the difference between the boiling and freezing points of water at sea level. The Kelvin scale uses the degree Celsius for its unit increment.|
|मोल||mol||पदार्थ या द्रव्य की मात्रा||A mole is the quantity of substance that contains the same number of elementary entities (atoms, molecules, ions, electrons or particles, depending on the substance) as there are atoms in 0.012 kilograms of pure carbon-12; this number (NA) is approximately equal to 6.0221415(10) × 1023 mol-1 (2002 CODATA).||one gram per atomic mass unit|
|कैण्डेला||cd||प्रकाशीय तीव्रता||The unit of luminous intensity is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 × 1012 hertz and that has a radiant intensity in that direction of 1⁄683 watts per steradian.
Defined by: 16th CGPM (1979) Resolution 3, CR 100