Wednesday, December 3, 2008

SI electricity units

edit

SI electromagnetism units

Symbol [citation needed]

Name of Quantity

Derived Units

Unit

Base Units

I

Magnitude of current

ampere (SI base unit)

A

A = W/V = C/s

q

Electric charge, Quantity of electricity

coulomb

C

A·s

U

Potential difference or Electromotive force

volt

V

J/C = kg·m2·s−3·A−1

R, Z, X

Resistance, Impedance, Reactance

ohm

Ω

V/A = kg·m2·s−3·A−2

ρ

Resistivity

ohm metre

Ω·m

kg·m3·s−3·A−2

P

Power, Electrical

watt

W

V·A = kg·m2·s−3

C

Capacitance

farad

F

C/V = kg−1·m−2·A2·s4

 

Elastance

reciprocal farad

F−1

V/C = kg·m2·A−2·s−4

ε

Permittivity

farad per metre

F/m

kg−1·m−3·A2·s4

χe

Electric susceptibility

(dimensionless)

-

-

G, Y, B

Conductance, Admittance, Susceptance

siemens

S

Ω−1 = kg−1·m−2·s3·A2

σ

Conductivity

siemens per metre

S/m

kg−1·m−3·s3·A2

H

Magnetic field, magnetic field intensity

ampere per metre

A/m

A·m−1

Φm

Magnetic flux

weber

Wb

V·s = kg·m2·s−2·A−1

B

Magnetic flux density, magnetic induction, magnetic field strength

tesla

T

Wb/m2 = kg·s−2·A−1 = N·A−1·m−1

 

Reluctance

ampere-turn per weber

A/Wb

kg−1·m−2·s2·A2

L

Inductance

henry

H

Wb/A = V·s/A = kg·m2·s−2·A−2

μ

Permeability

henry per metre

H/m

kg·m·s−2·A−2

χm

Magnetic susceptibility

(dimensionless)

-

-