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Veritasium "How Electricity Actually Works"

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electrodacus:

--- Quote from: IanB on May 18, 2022, 07:25:45 pm ---
Let's stop bringing up the energy stored in the capacitor. Everyone knows energy is stored in capacitors. Everyone agrees energy is stored in capacitors. Nobody has ever denied that energy is stored in capacitors. Stop acting like this a big mystery.

If we look at an energy balance on the system, we have:

1. The energy leaving the source (battery) is ES
2. The energy stored in the capacitor is EC
3. The energy consumed (dissipated) by the load resistor/LED is EL

Since you tell us that energy is always conserved, we know that  ES = EC + EL

Clearly some energy from ES ended up as EL, which means some energy was transferred from the battery to the load, and some energy was stored in the capacitor.

--- End quote ---

You claim that everyone understand that energy is stored in the capacitor but if that was to be true there will have been no discussion about energy passing through capacitor. Including you based on this post you just made.

And is not me that is saying energy is conserved that is a fact that has never been disproven.

Yes energy was transferred only through wires and some of that energy ended up as lost energy in the wires and load resistor that is also a wire just with higher resistance.

PlainName:

--- Quote ---As soon as an electron passes through the resistor an electron will also end up in the capacitor
--- End quote ---

What causes that (and all the other) electrons to pass through the resistor just when voltage is applied to the capacitor and not at other times?

electrodacus:

--- Quote from: dunkemhigh on May 18, 2022, 07:55:42 pm ---
--- Quote ---As soon as an electron passes through the resistor an electron will also end up in the capacitor
--- End quote ---

What causes that (and all the other) electrons to pass through the resistor just when voltage is applied to the capacitor and not at other times?

--- End quote ---


Like I mentioned many times before. Electrons are charged particles with negative charge so they repel each other.
You can say they are under pressure if you compare this with gas molecules.

Say a discharged capacitor that is basically an energy storage device has 500 free electrons on both plates that means 0V so discharged capacitor and then say capacitor is charged so you have 750 electrons on one side and 250 on the other side. What will happen if capacitor terminal are shorted ?
The wire shorting also has free electrons so the electrons on the plate with 750 electrons when in contact with the wire (closed loop) will want to go to the lowest energy state so electrons will be pushed out of that plate in to the wire and the other end of the wire will release an electron in the capacitor plate that has a deficit thus 749 and 251 will be the total after the first electron did the work.
In the end plates will get back to 500 and 500 electrons so no more stored energy and all that stored energy will end up as heat in the wire (wire temperature will increase with the exact amount that energy stored contained).

PlainName:
OK, forget it. It's a lost cause and I am out.

snarkysparky:
Energy is conserved.  At the instant the switch is closed the battery is providing 14.4 watts of power.

That 14.4 watts need to be accounted for everywhere.  Assuming zero resistance wires.   So  for the capacitor we have Joules / second  = watts and same for the resistor.

The capacitor is gaining zero energy at the instant the switch is closed.   

The capacitor IS passing energy through it.   Suppose the capacitor was infinite in capacitance.  No energy would ever be stored in it but load current could flow into one plate an out of the other plate with no transfer across the dielectric.

Maybe we are saying the same thing.

What is happening is that the for the plates of the capacitor to "charge" relative to each other current must flow into and out of the plates but NOT across the dielectric barrier.

And instantaneously the energy balance at the start is  that no energy is being stored in the capacitor.  And somehow energy shows up at the resistor.

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