|
SI Derived Units
|
| Quantity |
SI
derived unit |
| Name |
in terms of other units... |
Expression in terms of SI
base units |
| plane angle |
radian (a) |
rad |
|
m.m-1
= 1 (b) |
| solid angle |
steradian (a) |
sr (c) |
|
m2.m-2
= 1 (b) |
| frequency |
hertz |
Hz |
|
s-1 |
| force |
newton |
N |
|
m.kg.s-2 |
| pressure, stress |
pascal |
Pa |
N/m2 |
m-1.kg.s-2 |
| energy, work, quantity of
heat |
joule |
J |
N.m |
m2.kg.s-2 |
| power, radiant flux |
watt |
W |
J/s |
m2.kg.s-3 |
| electric charge, quantity
of electricity |
coulomb |
C |
|
s.A |
| electric potential difference,
electromotive force |
volt |
V |
W/A |
m2.kg.s-3.A-1 |
| capacitance |
farad |
F |
C/V |
m-2.kg-1.s4.A2 |
| electric resistance |
ohm |
W |
V/A |
m2.kg.s-3.A-2 |
| electric conductance |
siemens |
S |
A/V |
m-2.kg-1.s3.A2 |
| magnetic flux |
weber |
Wb |
V.s |
m2.kg.s-2.A-1 |
| magnetic flux density |
tesla |
T |
Wb/m2 |
kg.s-2.A-1 |
| inductance |
henry |
H |
Wb/A |
m2.
kg.s-2.A-2 |
| Celsius temperature |
degree Celsius(d) |
ŸC |
|
K |
| luminous flux |
lumen |
lm |
cd.sr (c) |
m2.m-2.cd
= cd |
| illuminance |
lux |
lx |
lm/m2 |
m2.m-4.cd
= m-2.cd |
| activity (referred to a
radionuclide) |
becquerel |
Bq |
|
s-1 |
| absorbed dose, specific
energy (imparted), kerma |
gray |
Gy |
J/kg |
m2.s-2 |
| dose equivalent, ambient
dose equivalent, directional dose equivalent, personal
dose equivalent, organ equivalent dose |
sievert |
Sv |
J/kg |
m2.s-2 |
|
|
|
(a) The radian and steradian may
be used with advantage in expressions for derived units to distinguish
between quantities of different nature but the same dimension.
(b) In practice, the symbols rad
and sr are used where appropriate, but the derived unit "1"
is generally omitted.
(c) In photometry, the name steradian
and the symbol sr are usually retained in expressions for units.
(d) This unit may be used in combination
with SI prefixes, e.g. millidegree Celsius, mŸC.
|
