VQ = Energy, VI = P

VQ = Energy

The above equation is not so often seen as P (Power) = VI. As Energy is P x time, and I = Q (Charge) / time

VQ ---> V x I x time ---> P x time ---> Energy

So the equation is correct and very simple or even elegant. But what does VQ mean ?

VQ is mathematically V times Q or V multiplied by Q or the product of V and Q. But in terms of Physics VQ may have some meaning.

I is the time ratio of Q, time is related so dynamic while Q itself is not, and electrical quantity. If V is static (no change with time) this Energy (VQ) is static too or we could say potential. And Energy is scalar not a vector quantity.

We could say

P (Power) = VI (and P x time = Energy) is dynamic as far as V or I or both change with time while VQ = Energy is static as far as V does not change with time.

VQ is also regarded as Work. Penguin Dictionary of Physics explain:

"
work  Symbol W; unit: joule.

4. If a charge Q is displaced between two points with potential difference U the work done electrically is QU. The unit of potential difference, the volt, is so defined that if work is in joules and charge in coulobms, then U is volts.

"

But I think that work is more like a definition than a meaningful physical property. Is energy simply a definition too?

We can make a simple modification of the equation VQ = Energy, we can get

V = Energy / Q, or

Voltage is Energy per Charge.



sptt