In this article, we will learn about some important Electrical Units and Symbols used for measuring various electrical parameters or quantities. An electrical unit or electrical measurement unit can be defined as a standardized quantity that can be used to measure other electrical quantities like current, voltage, power, energy, frequency, and many others. Electrical units play an important role in quantifying and describing the behavior of electrical circuits in a standard or universally accepted manner.
Importance of Electrical Units of Measure
The following are some key reasons that make electrical units of measure important in the field of electrical engineering –
- They standardize the measurement system so engineers can globally interpret the measured values in the same way.
- Electrical units of measurement help in meeting regulatory standards and compliance.
- Electrical units are also important for designing, analyzing, testing, and validating electrical circuits and systems.
- Electrical units also help in troubleshooting circuits and systems, as they provide a way of comparing measured values with standard values.
SI Units of Base Electrical Quantities
SI Units of electrical quantities are nothing but units of electrical quantities defined by the International System of Units. These units are also used to derive several other electrical units. The following are some key SI units of base electrical quantities –
- Ampere – Ampere is the SI unit of electric current, and it is denoted by A.
- Volt – Volt is the SI unit of electric potential or voltage, and it is denoted by V.
- Ohm – Ohm is the SI unit of electrical resistance, and it is denoted by Ω.
- Watt – Watt is the SI unit of electric power, and it is denoted by W.
Electrical Units List
The following table provides a list of very useful and important units of electrical quantities –
| Electrical Quantity | Unit of Measurement |
Symbol |
| Electric Current | Ampere |
A |
| Voltage or Electric Potential | Volt |
V |
| Resistance | Ohm |
Ω |
| Conductance | Siemens |
S |
| Electric Charge | Coulomb |
C |
| Electric Power | Watt |
W |
| Electrical Energy | Joule |
J |
| Electric Field Intensity | Volt per meter |
V/m |
| Magnetic Flux | Weber |
Wb |
| Magnetic Flux Density | Tesla |
T |
| Inductance | Henry |
H |
| Capacitance | Farad |
F |
| Frequency | Hertz |
Hz |
| Impedance | Ohm |
Ω |
| Reactance | Ohm |
Ω |
| Electrical Energy (Commercial Unit) | kilowatt-hour |
kWh |
| Temperature | Kelvin |
K |
| Time | Second |
s |
| Work | Joule |
J |
| Current Density | Ampere per sq meter |
A/m² |
| Resistivity | Ohm-meter |
Ω-m |
| Permittivity | Farad per meter |
F/m |
| Permeability | Henry per meter |
H/m |
| Angular Frequency | Radian per second |
rad/s |
| Phase Angle | Radian or Degree |
rad or ° |
| Signal Gain (Log scale) | Decibel |
dB |
| Noise Figure | Decibel |
dB |
| Attenuation | Decibel |
dB |
| Bandwidth | Hertz |
Hz |
| Total Harmonic Distortion (THD) | Percentage |
% |
| Efficiency | Percentage |
% |
| Temperature Coefficient | Per °C |
/°C |
| Luminous Flux | Lumen |
lm |
| Illuminance | Lux |
lx |
| Torque | Newton-meter |
N-m |
| Force | Newton |
N |
| Pressure | Pascal |
Pa |
| Charge Density | Coulomb per cubic meter |
C/m³ |
| Electric Displacement | Coulomb per cubic meter |
C/m³ |
| Magnetic Field Intensity | Ampere per meter |
A/m |
| Magnetomotive Force (MMF) | Ampere-turns |
AT |
| Reluctance | Ampere-turns per weber |
AT/Wb |
| Signal-to-Noise Ratio (SNR) | Decibel |
dB |
| Duty Cycle | Percentage |
% |
Conclusion
Hence, this is all about electrical units and their symbols. This article provides a comprehensive study of electrical unit definition, importance, and also provides a list of various electrical quantities. These electrical units are very useful in both academic and practical electrical engineering.