Tab Electronics Guide to Understanding Electricity ... - Sciences Club

60 Chapter Two
symbol for micro, instead of “m,” to avoid confusion with the symbol
used for the prefix “milli.”
The following list provides some examples of how prefixes would be
used in conjunction with common circuit variables. The abbreviation
provided with each example is the way that value would actually be
written on schematics or other technical information.
EXAMPLES
1 picovolt 0.000000000001 volt (abbrev. 1 pV)
15 nanoamps 0.000000015 amp (abbrev. 15 nA)
200 microvolts 0.0002 volt (abbrev. 200 V)
78 milliamps 0.078 amp (abbrev. 78 mA)
400 Kilowatts 400,000 watts (abbrev. 400 KW)
3 Megawatts 3,000,000 watts (abbrev. 3 MW)
Using Ohm’s Law in Real-World
Circumstances
Thus far, you have been exposed to the basic concept of Ohm’s law and
how circuit variables have a definite and calculable relationship to each
other. As you have seen, the mathematics involved with Ohm’s law are
not difficult, but it takes some practice to become proficient at applying
Ohm’s law correctly. For example, in the early stages of becoming accustomed
to using Ohm’s law, it is a common error to mistakenly mix up
(or confuse) circuit variables with individual component variables. It is
also easy to misplace a decimal point when working with the various
standardized prefixes (milli, micro, Mega, etc.).
When electronics professionals draw a complete circuit diagram of a
complex electronic system, usually referred to as a schematic, they often
complicate the easy visualization of circuit subsections in the effort to
make the complete schematic fit into a nice, neat, aesthetically pleasing
square or rectangle. This means that the electronics enthusiast must
become proficient at being able to visualize a parallel circuit, for example,
drawn horizontally, vertically, or in any number of possible configurations.
In other words, it is necessary to develop the ability to
conceptualize a schematic, which means merely being capable of mentally
simplifying it into familiar subsections that can be easily worked with.