Measurement of Some Fundamental and Derived Quantities

Things to remember

• One standard meter is defined as the distance between two fine lines on a platinum-iridium rod preserved at temperature of 273.16 K and 760 mm of hg pressure.
• One standard second is defined as time taken by cesium -133 to make 91923177o.
• One standard kilogram is defined as the mass of platinum -iridium cylinder of diameter equal to its height.
• A solar day is defined as the time interval between the consecutive passages of the sun through zenith.
• The space occupied by a body is called volume. In SI system, the unit of volume is a cubic meter (m3).