Metric Prefixes and SI Units
SI Units
We've been measuring stuff for millennia, and our units used for those measures have been evolving since then. There are now dozens of units to describe physical quantities. For example, length can be measured by the foot, meter, fathom, chain, parsec, league, and so on. In order to better communicate measurements, we needed a standardized system of units, which every scientist and measurer could use to share their findings. This standardized system has come to be called the \
Physical SI Units
Quantity | SI Unit | Unit Abbreviation |
---|---|---|
Time | second | s |
Length | meter | m |
Mass | gram | g |
Temperature | kelvin | K |
Force | newton | N |
While we can still use units like feet or miles for distance (instead of meters), liters to describe volume (instead of m3), and Fahrenheit or Celsius to describe temperature (instead of °K), the units above are a standardized way for every scientist to share their measurements. Using the units above means everyone is speaking the same language.
Common Electronics Units
In dealing with electronics, there are a handful of units we'll be encountering more often than others. These include:
Quantity | SI Unit | Unit Abbreviation |
---|---|---|
Electric Potential Difference (Voltage) | volts | V |
Electric Current | ampere | A |
Power | watt | W |
Energy/Work/Heat | joule | J |
Electric Charge | coulomb | C |
Resistance | ohm | Ω |
Capacitance | farad | F |
Inductance | henry | H |
Frequency | hertz | Hz |
Now that we know the units, let's look at how they can be augmented with prefixes to make them even more usable!