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Council Directive of 20 December 1979 on the approximation of the laws of the Member States relating to units of measurement and on the repeal of Directive 71/354/EEC (80/181/EEC)

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[X1 [F11.2.3. SI derived units with special names and symbols U.K.
a

Special names for the unit of power: the name volt–ampere (symbol VA ) when it is used to express the apparent power of alternating electric current, and var (symbol var ) when it is used to express reactive electric power. The var is not included in GCPM resolutions.

Quantity Unit Expression
Name Symbol In terms of other SI units In terms of SI base units
Plane angle radian rad m · m –1
Solid angle steradian sr m 2 · m –2
Frequency hertz Hz s –1
Force newton N m · kg · s –2
Pressure, stress pascal Pa N · m –2 m –1 · kg · s –2
Energy, work; quantity of heat joule J N · m m 2 · kg · s –2
Power a , radiant flux watt W J · s –1 m 2 · kg · s –3
Quantity of electricity, electric charge coulomb C s · A
Electric potential, potential difference, electromotive force volt V W · A –1 m 2 · kg · s –3 · A –1
Electric resistance ohm Ω V · A –1 m 2 · kg · s –3 · A –2
Conductance siemens S A · V –1 m –2 · kg –1 · s 3 · A 2
Capacitance farad F C · V –1 m –2 · kg –1 · s 4 · A 2
Magnetic flux weber Wb V · s m 2 · kg · s –2 · A –1
Magnetic flux density tesla T Wb · m –2 kg · s –2 · A –1
Inductance henry H Wb · A –1 m 2 · kg · s –2 · A –2
Luminous flux lumen lm cd · sr cd
Illuminance lux lx lm · m –2 m –2 · cd
Activity (of a radionuclide) becquerel Bq s –1
Absorbed dose, specific energy imparted, kerma, absorbed dose index gray Gy J · kg –1 m 2 · s –2
Dose equivalent sievert Sv J · kg –1 m 2 · s –2
Catalytic activity katal kat mol · s –1

Units derived from SI base units may be expressed in terms of the units listed in Chapter I.

In particular, derived SI units may be expressed by the special names and symbols given in the above table; for example, the SI unit of dynamic viscosity may be expressed as m –1 · kg · s –1 or N · s · m –2 or Pa · s.] ]

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