Meter: It is the unit length. A meter is defined the distance between two marks platinum - iridium bar kept 0 degree C in the international Bureau of weight and measures near Pairs.
The problem with metal standards of kind is they are liable to under go small changes in length as the years go. It was there fore decided in 1960 to choose a particular wavelength of light standardise a meter. Thus:
1 m=1650763.73 wavelength of krypton radiation.
The multiple and sub multiples units of a meter are very easily obtained by multiplying and dividing in by 10 as follows
1 km=1000 m = 103
1 mm= 1/1000 m=103 m
Kilo gram: The mass of a cylinder of specific dimension of platinum-iridium alloy kept in the internal Bureau of weight and measures near Paris is taken to be the standard one kilo gram. A few of its sub multiples are given below:
1 g=1/1000 kg= 10-3 kg
1 Miligram = 1/1000,000 kg =10-6 kg
1 Miligram = 1/1000 g = 10-3 g
Second: The 1/86400 part of the mean solar of the year 1900 is called a standard second.
In 1967, the standard second was redefined as " A second is the duration in which the cesium - 133 atom completes 9,192,631,770 vibrations. One such clock is at national Bureau of standard, Washington USA. Its related units are:
60 seconds = 1 minute
60 minutes = 1 hour.
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