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.
- REVIEW:
- Power is additive in any configuration of resistive
circuit: PTotal = P1 + P2 + . . .
Pn
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