GENERAL TALKS - பொதுவான SCIENCE அடைப்படையிலான அளவீடு யூனிட்களை பார்க்கலாமா ? [00007]

1. Meter (m): The meter is the SI unit of length and is defined as the distance traveled by light in a vacuum during a time interval of 1/299,792,458 of a second.

2. Kilogram (kg): The kilogram is the SI unit of mass and is defined as the mass of the International Prototype of the Kilogram, which is a platinum-iridium cylinder kept at the International Bureau of Weights and Measures.

3. Second (s): The second is the SI unit of time and is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom.

4. Ampere (A): The ampere is the SI unit of electric current and is defined as the constant current that, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in a vacuum, would produce between these conductors a force equal to 2 x 10^-7 newton per meter of length.

5. Kelvin (K): The kelvin is the SI unit of temperature and is defined as the fraction 1/273.16 of the thermodynamic temperature of the triple point of water.

6. Mole (mol): The mole is the SI unit of amount of substance and is defined as the amount of substance that contains as many elementary entities (such as atoms, molecules, ions, electrons) as there are atoms in 0.012 kilograms of carbon-12.

7. Candela (cd): The candela is the SI unit of luminous intensity and is defined as the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540 x 10^12 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.