Power calculations
When calculating the power dissipation of
resistive components, use any one of the three power
equations to derive and answer from values of voltage,
current, and/or resistance pertaining to each component:
This is easily managed by adding another row
to our familiar table of voltages, currents, and
resistances:
Power for any particular table column can be
found by the appropriate Ohm's Law equation (appropriate
based on what figures are present for E, I, and R in that
column).
An interesting rule for total power versus
individual power is that it is additive for any
configuration of circuit: series, parallel, series/parallel,
or otherwise. Power is a measure of rate of work, and since
power dissipated must equal the total power applied
by the source(s) (as per the Law of Conservation of Energy
in physics), circuit configuration has no effect on the
mathematics.
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