Ch 1.b - Electrical Units

Common Prefixes

Prefix

 

Prefix

Symbol

Prefix

factor

Example
pico p 10-12 1pF = 10-12F
nano n 10-9 1nF = 10-9F
micro μ 10-6 1μA = 10-6A
milli m 10-3 1mA = 10-3A
kilo K 103 1KΩ = 1000Ω
mega M 106 1MHz = 106Hz
giga G 109 1GHz = 109Hz

 

Common Electrical Units

Unit Name Unit Symbol Quantity
Ampere (amp) A Electric current (I)
Volt V Voltage (V, E)

Electromotive force (E)

Electric potential (φ)

Ohm Ω Resistance (R)

Impedance (Z)

Watt W Electric power (P)
Decibel-milliwatt dBm Electric power (P)
Decibel-Watt dBW Electric power (P)
Volt-Ampere-Reactive VAR Reactive power (Q)
Volt-Ampere VA Apparent power (S)
Farad F Capacitance (C)
Henry H Inductance (L)
siemens / mho S Conductance (G)

Admittance (Y)

Coulomb C Electric charge (Q)
Ampere-hour A·h Electric charge (Q)
Joule J Energy (E)
Kilowatt-hour kWh Energy (E)
Electron-volt eV Energy (E)
Ohm-meter Ω∙m Resistivity (ρ)
siemens per meter S/m Conductivity (σ)
Volts per meter V/m Electric field (E)
Newtons per coulomb N/C Electric field (E)
Volt-meter V·m Electric flux (Φe)
Tesla T Magnetic field (B)
Gauss G Magnetic field (B)
Weber Wb Magnetic flux (Φm)
Hertz Hz Frequency (f)
Seconds s Time (t)
Meter / metre m Length (l)
Square-meter m2 Area (A)
Decibel dB  
Parts per million ppm