# Power Calculations

When calculating the power dissipation of resistive components, use any one of the three power equations to derive the answer from values of voltage, current, and/or resistance pertaining to each component:

*Power Equations*

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: P_{Total}= P_{1}+ P_{2}+ . . . P_{n}

**Lessons In Electric Circuits** copyright (C) 2000-2020 Tony R. Kuphaldt, under the terms and conditions of the** ***CC BY License**.*

**Lessons In Electric Circuits**

*CC BY License*

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See the Design Science License (Appendix 3) for details regarding copying and distribution.

Revised November 06, 2021

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