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Veritasium "How Electricity Actually Works"

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HuronKing:

--- Quote from: electrodacus on May 19, 2022, 07:38:51 pm ---
--- Quote from: HuronKing on May 19, 2022, 07:35:25 pm ---
It's worse than that. electrodacus doesn't understand displacement current.

He keeps saying "electrical current" hoping this smokescreen will distract from his ignorance of there being TWO terms for current in Ampere's Law - the conduction current AND the displacement current. In the region between two capacitors, there is no conduction current, but there IS displacement current.

Asserting that displacement current propagates no energy is anti-Maxwell.

--- End quote ---

Provide an answer to the problem then let me know the amount of energy that passed "through" capacitor.

--- End quote ---

It's the same energy you believe only exists when conduction current flows - this is what Ampere's Law is trying to tell you.

@Naej

--- Quote ---No they don't. They are equations giving the curl/divergence of two functions, and none of the two are energy.

--- End quote ---

https://web.mit.edu/6.013_book/www/chapter11/11.2.html

--- Quote ---The electric and magnetic fields are confined to the free space regions. Thus, power flow and energy storage pictured in terms of these variables occur entirely in the free space regions.

--- End quote ---

The Poynting Vector is derived from Maxwell's Eqs. If Maxwell's Eqs are true - then so is Poynting.

PlainName:

--- Quote from: TimFox on May 19, 2022, 07:36:09 pm ---In profane usage, the middle initial is "H".

--- End quote ---

Ah, but this was crude profanity  >:D

snarkysparky:

Ahite.  I got your numbers.  And discovered how rusty i am at this stuff.   skool was a long time ago

a) How much energy will power supply deliver in one second after the discharged capacitor was connected ?       ->  0.1439 Joules

b) How much energy will end up as heat dissipated by wires?    -> 0.0719 joules 

c) How much energy is stored in the capacitor after this second?   ->  0.0720  Joules

d) How much energy is delivered by the source in the next second? so after first second ended and another second from that point.     -> 0    ( time constant is 1 ms ) 


What does this mean?


snarkysparky:
I tell ya what I think it means.

The resistance of the wires got to dissipate as much energy as is stored in the capacitor.

And the current that made this possible went into one terminal of the capacitor and out the other terminal.   I call this "through"   what do you call it ?

Naej:

--- Quote from: HuronKing on May 19, 2022, 08:05:19 pm ---
--- Quote ---No they don't. They are equations giving the curl/divergence of two functions, and none of the two are energy.

--- End quote ---

https://web.mit.edu/6.013_book/www/chapter11/11.2.html

--- Quote ---The electric and magnetic fields are confined to the free space regions. Thus, power flow and energy storage pictured in terms of these variables occur entirely in the free space regions.

--- End quote ---

The Poynting Vector is derived from Maxwell's Eqs. If Maxwell's Eqs are true - then so is Poynting.

--- End quote ---
These are 2 completely different things: Maxwell's equations describe an approximation of physics (a very good one when the number of photons is large, and their energy small compared to electrons); Poynting's theorem is well, a theorem (not an approximation), which is true if you assume Maxwell's equations are correct. Maxwell had nothing do to with ExH, and there's no dD/dt in ExH.

The important part of the quote is what I put in bold, it's a picture, and you might as well take S=JV.

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