How do voltage and current combine to determine electrical power?

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Discussion Overview

The discussion revolves around the relationship between voltage, current, and electrical power, exploring the fundamental definitions and equations that connect these concepts. Participants examine the definitions of voltage and current, and how they contribute to the calculation of power in electrical systems.

Discussion Character

  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant questions the reasoning behind the equation for electrical power, seeking clarification on how power relates to voltage and current.
  • Another participant explains that since voltage is defined as joules per coulomb and current as coulombs per second, multiplying voltage by current results in joules per second, which defines power.
  • A different viewpoint emphasizes the formula for power dissipation as R*I², suggesting its correctness for both DC and AC systems.
  • There is a correction regarding the definition of voltage, with a participant asserting that voltage should be described as a difference in potential rather than a difference in charge.

Areas of Agreement / Disagreement

Participants express different perspectives on the definitions and equations related to electrical power, indicating that multiple competing views remain without a consensus on the preferred approach or terminology.

Contextual Notes

Some participants emphasize the importance of rigor in understanding basic units and definitions, suggesting that misunderstandings may arise from imprecise language or assumptions.

polekitten
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Why does electrical power = voltage x current? I understand power is the rate of doing work or the rate of energy transfer but how does that relate to voltage an current?

I know current is the flow of charge and voltage is a difference in charge between 2 points.
 
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Because voltage = joules/coulomb and
current = coulombs/second so

Voltage * current = joules/second

Which is the definition of power.
 
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Likes   Reactions: Entanglement, davenn and anorlunda
polekitten said:
Why does electrical power = voltage x current?
I prefer to state Power dissipated = R*I2. This is correct both for DC and AC.
 
polekitten said:
voltage is a difference in charge between 2 points.
er, uh, make that "voltage is a difference in potential"

Be very rigorous about learning your basic units .
 

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