This website uses cookies. You can see our cookies policy, here - If you continue browsing this site, you are accepting its use.  
Cookies policy +

Electrical Magnitudes, Units and Symbols

The physical magnitude is all that property that can be measured and its result expressed by a number that indicates its quantity based on one unit. These quantities can be multiples or submultiples of the unit and their values are represented in the International System with abbreviation and symbols.

On this page we show the fundamental physical quantities related to electrical science and engineering and the like, along with their units, abbreviation, symbols and basic calculations.

Quantities, units, abbreviations, symbols and basic calculations

Magnitud Unit Abbreviation Symbol Basic calculation

Electrical Basic Magnitudes

Go to the top of the page
Electric current Amp I A I = V / R
V - voltage
R - resistance
Voltage Volt V
U
V V = R . I
R - resistance
I - electric current

Resistive Magnitudes

Go to the top of the page
Electrical resistance Ohm R Omega
Omega
R = V / I
Ohm's law
Conductance Siemens
Mho
G Inverted Omega
Inverted Omega
G = 1 / R
Impedance Ohm Z Omega
Omega
 
Resistivity Ohm / meter / mm2
( 20º)
Ro
Ro
Ro
Ro
Ro = Ohm / m / mm2

Capacitive Magnitudes

Go to the top of the page
Capacity farad C F C = load / voltage
capacitive reactance Ohm Xc Omega
Omega
Xc = 1 / pulsation . capacity
Coefficient lost capacitor In decimal No. d d d = Xc / Rp
Rp = resistance losses
Capacitor quality factor In decimal No. Q Q Q = 1 / d
Dielectric Constant Farad / meter     F / m

Inductive Magnitudes

Go to the top of the page
inductance Henry L H
Hr
L = flow / current
Inductive reactance Ohm Xl Omega
Omega
XL = Pulsation / L
Coefficient lost coils
inductors
In decimal No. d d d = R / XL
Quality factor of the coils
inductors
In decimal No. Q Q Q = XL / R
Permeability Henry / meter     H / m

Electrical Signal magnitudes

Go to the top of the page
Frequency Hertz F Hz F = 1 / T
T = period
Frequency = Cycle
Wavelength Meter Landa
Landa
Landa
Landa
Landa = Speed . frequency
Pulsation 1 / seconds Minuscule omega
Minuscule omega
Minuscule omega
Minuscule omega
Minuscule omega= 2 . Pi . Frequency
Period Seconds T T T = 1 / F
Angular speed Radian / Second   rad / s Angular speed = rad / s

Electromagnetic Magnitudes

Go to the top of the page
Electrical load Culombio Q Q 1Q = 6.23.1018 electrons
Intensity of electrical field Voltage / length E E E = Voltage / length
Intensity of magnetic field Gauss
Ampere / meter
H H H = MMF / length
Magnetomotriz forces Gilbert
Ampere - return
MMF Theta
Theta
MMF = I . No of turns
Magnetic flux Weber
Maxwell
Wb
M
Phi
Phi
Wb = V . Second
Magnetic induction Tesla
Gauss
T
G
B B = Magnetic flux / m2

Magnitudes of Electrical Work

Go to the top of the page
Electrical power Watt P W P = V . I
Current density Ampere / mm2 J J J = I / mm2
Electrical work Watt / second
( Joule )
W Ws W = Power . Time
Electrical performance Decimal Nº
% Percentage
Eta
Eta
Eta
Eta
Eta = P. output / P. consumption

Ilumination magnitudes

Go to the top of the page
Luminous flow Lumen Lm Phi
Phi
 
Luminous Intensity Candela cd cd  
Luminous efficacy Lumen / Watt cd Eta
Eta
cd = Lm / Watt
Lighting Lux Lx E Lx = Lm / m2
Luminance Candela / m2 Cd / m2 L L = Cd / m2

Thermal Magnitudes

Go to the top of the page
Temperature Degrees Celsius
Degrees Fahrenheit
Degrees Kelvin
T ºC
ºF
ºK
 
Heat quantity Joule
Kilocalorie
J
Kcal
Q 1 Kcal = 1000 cal = 4180 J
Calorific capacity Joule / K
Kilocalorie / K
J / K
Kcal / K
K  
Thermal resistance K / W Rth Rth Rth = DeltaT / P. dissipated
DeltaT = Increase of temperature

General Magnitudes in the Physics

Go to the top of the page
Time Second t s  
Length Meter L m  
Force Newton F N  
Mass Gram m g  
Energy Joule E J  
Pressure Pascal P Pa  
Sonority and logarithmic scales of power Bel - Decibel dB dB db = Bel / 10

Other Magnitudes

Go to the top of the page
Susceptance Siemens B S  
Admittance Siemens Y S  
Speed Meter / Second V m / s V = m / s
Speed of transmission
of information
Baud bps bps bps = Bits . Second

Follow us...
facebook_logo  logo  twitter_logo