UNITS, DIMENSIONS
One meter is the length of path traveled by light in vacuum during a time
1
interval of of a second.
299,792,458
Length
(Earlier)
1,650,763.73 wavelengths in vacuum of radiation corresponding to orange
red light of krypton-86.
One second is defined as 9,192,631,770 time periods of particular radiation
Time
of Cesium-133.
One kilogram is defined as the mass of a platinum-iridium cylinder kept at
Mass the International Bureau of Weights and Measures, France.
(Earlier) One kilogram is the mass of water at 4ºC.
One ampere is that constant current, which when flows through two
infinitely long straight parallel conductors of negligible cross-section, kept
Electric
one meter apart in vacuum, produces between them force of 2 × 10–7 N/m
Current
per unit length.
1
One kelvin is equal to the fraction of the thermodynamic
Temperature 273.16
temperature of triple point of water.
One mole is the amount of substance of a system which contains as many
Amount of
elementary particles/entities (atoms, molecules, ions etc.) as there are
substance
atoms in 0.012 kg of carbon–12
One candela is the luminous intensity in a given direction of a source that
emits monochromatic radiation of 540 × 1012 Hz and that has a radiant
intensity in that direction of 1/683 watt per steradian.
Luminous (Earlier)
Intensity One candela is the luminous intensity of a blackbody of surface area
1
m2 placed at a temperature of freezing platinum and at a pressure
6,00,000
of 1.01325 × 105 N/m2 in the direction perpendicular to its surface.
One radian is the plane angle between two radii of a circle which cut off on
Plane angle the circumference an arc equal to the length of the radius.
One steradian is the solid angle which having its vertex at the centre of the
Solid Angle sphere, cut off an area of surface equal to that of a square with sides of
length equal to the radius of the sphere.
One curie is the quantity of any radioactive substance which undergoes
Radioactivity 3.7 × 1010 disintegrations per second.
Note: Use of curie is now discouraged by SI and new unit is Becquerel.
Units, Dimensions Page No: 1
One meter is the length of path traveled by light in vacuum during a time
1
interval of of a second.
299,792,458
Length
(Earlier)
1,650,763.73 wavelengths in vacuum of radiation corresponding to orange
red light of krypton-86.
One second is defined as 9,192,631,770 time periods of particular radiation
Time
of Cesium-133.
One kilogram is defined as the mass of a platinum-iridium cylinder kept at
Mass the International Bureau of Weights and Measures, France.
(Earlier) One kilogram is the mass of water at 4ºC.
One ampere is that constant current, which when flows through two
infinitely long straight parallel conductors of negligible cross-section, kept
Electric
one meter apart in vacuum, produces between them force of 2 × 10–7 N/m
Current
per unit length.
1
One kelvin is equal to the fraction of the thermodynamic
Temperature 273.16
temperature of triple point of water.
One mole is the amount of substance of a system which contains as many
Amount of
elementary particles/entities (atoms, molecules, ions etc.) as there are
substance
atoms in 0.012 kg of carbon–12
One candela is the luminous intensity in a given direction of a source that
emits monochromatic radiation of 540 × 1012 Hz and that has a radiant
intensity in that direction of 1/683 watt per steradian.
Luminous (Earlier)
Intensity One candela is the luminous intensity of a blackbody of surface area
1
m2 placed at a temperature of freezing platinum and at a pressure
6,00,000
of 1.01325 × 105 N/m2 in the direction perpendicular to its surface.
One radian is the plane angle between two radii of a circle which cut off on
Plane angle the circumference an arc equal to the length of the radius.
One steradian is the solid angle which having its vertex at the centre of the
Solid Angle sphere, cut off an area of surface equal to that of a square with sides of
length equal to the radius of the sphere.
One curie is the quantity of any radioactive substance which undergoes
Radioactivity 3.7 × 1010 disintegrations per second.
Note: Use of curie is now discouraged by SI and new unit is Becquerel.
Units, Dimensions Page No: 1
