Ian asked in Science & MathematicsPhysics · 1 month ago

wattage is equal to volts/amperage?

Can someone explain this to me is energy referring to watts (P) in the explanation below P = VI This is simply (energy/charge) × (charge/time). For V in

volts and I in amps, P comes out in watts. A watt is a

joule per second (1 Watt = 1 J/s). i always thought it just volts over amps but the explanation confused me and now im not sure

2 Answers

  • 1 month ago
    Favorite Answer

    It comes out of Ohm's Law but you can get more fundamental than that. Suppose you have a charge q, and it moves through a potential difference V where V has units of J/Coul = volts.  The charge gains a kinetic energy K = qV note that this is in Joules.

    Now lets say it takes the charge a time t to move through the potential difference.  Then the rate of energy gain is dK/dt ~ qV/t but q/t is a currnet call that I so

    dK/dt ~ V*I and noting thake dK/dt has units of J/s we can call that power P so

    P = V*I

  • 1 month ago


    in an electrical circuit, DC, power in watts equals voltage in volts multiplied by current in amperes.

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