While it might seem a little silly to document polarity of voltage drop in this circuit, it is
an important concept to master. It will be critically important in the analysis of more complex
circuits involving multiple resistors and/or batteries.
It should be understood that polarity has nothing to do with Ohm’s Law: there will never
be negative voltages, currents, or resistance entered into any Ohm’s Law equations! There are
other mathematical principles of electricity that do take polarity into account through the use
of signs (+ or -), but not Ohm’s Law.