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Guidelines for Examination

 
 
4.
Units and names of units permitted in specialised fields only 

Quantity

Unit
Name


Symbol


Value

Vergency of optical systems

Dioptre

 

1 dioptre = 1 m-1

Mass of precious stones

metric carat

 

1 metric carat = 2 x 10-4 kg

Area of farmland and building land

are

a

1 a = 102 m2

Mass per unit length of textile yarns and threads

tex

tex

1 tex = 10-6 kg.m-1

Blood pressure and pressure of other body fluids

millimetre of mercury

mm Hg

1 mm Hg = 133,322 Pa

Effective cross-sectional area

Barn

b

1b = 10-28 m2

 

The prefixes and their symbols listed in F-II, Annex 2, 1.3 may be used in conjunction with the above units and symbols, with the exception of the millimetre of mercury and its symbol. The multiple of 102 a is, however, called a "hectare".