Basic Electrical Theory
UNITS OF ELECTRICAL MEASUREMENT
UNITS OF ELECTRICAL MEASUREMENT
Using Ohm’s Law and the System Internationale (SI) Metric System, electrical
measuring units can be derived.
EO 1.3
DESCRIBE the following electrical parameters, including the
unit of measurement and the relationship to other parameters.
a.
Voltage
b.
Current
c.
Resistance
d.
Conductance
e.
Power
f.
Inductance
g.
Capacitance
EO 1.4
Given any two of the three component values of Ohm’s Law,
DETERMINE the unknown component value.
System Internationale (SI) Metric System
Electrical units of measurement are based on the International (metric) System, also known as
the SI System. Units of electrical measurement include the following:
Ampere
Volt
Ohm
Siemens
Watt
Henry
Farad
Appendix A provides more information concerning the metric system, metric prefixes, and
powers of 10 that are used in electrical measuring units.
Voltage
Voltage, electromotive force (emf), or potential difference, is described as the pressure or force
that causes electrons to move in a conductor. In electrical formulas and equations, you will see
voltage symbolized with a capital E, while on laboratory equipment or schematic diagrams, the
voltage is often represented with a capital V.
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