Comments by "Jovet" (@jovetj) on "How ELECTRICITY works - working principle" video.

  1. Key point I think was overlooked: the more electrons in the outermost shell, the stronger the nucleus holds onto them. This is why materials with just one valence electron (living in the outermost shell) make the best conductors of electricity—they are the loosest held by the atom. Valence electrons even make the atom smaller.... an atom with two valence electrons will be just slightly smaller in diameter than the atom with one less proton/electron: the nucleus holds the electrons tighter and closer, which makes the atom's diameter slightly smaller. The metals copper, silver, and gold are excellent conductors because they have one valence electron and the size of the atoms is a "sweet spot" for how loosely that valence electron is held.
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  2.  @onichan924  Yes, their precise location in space is probabilistic, but the probability outside of those shells is practically zero.
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  3. It's a bit complicated to explain (let alone understand), but in the simplest sense the electrons are moving too fast to actually collide with the nucleus. In this sense it's like the Earth: the Earth is moving too fast around the sun to be pulled into it. But, unlike the Earth, the electrons around an atom's nucleus are a cloud and not distinct particles. Each electron is "everywhere at once" in its shell because its actual energy is a compromise between the kinetic energy the electron has and its potential energy with its charge attraction to the nucleus. Quantum mechanics has all the details.
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  4. Yes, more or less. But because electrons are not an easily defined and finite "particle" but more of a "cloud" they are also almost everywhere around the atom (at their energy level) at once. Quantum Mechanics is deep stuff.
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  5.  @jordansutche9829  It's a key point for the why. Not the how.
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  6. A circuit is formed when there is a continuous path for electrons (or electrical potential) from a power source around and back to that power source. The power source is like a "pump" which recirculates the electrons continuously, as long as current is flowing. If the continuous path is ever broken, then all electrons stop flowing in the circuit instantaneously. A short circuit is when the contiguous path is very short and offers little to no resistance. This is bad because more energy could flow through the circuit than it is designed to handle (wires could melt) and/or it could destroy the power source. To be practical, electric current needs to flow through a resistance, called "the load," to do some kind of work. The load is the natural limiter of current flowing through a circuit, and can be anything from a light to a motor or so on.
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  7. 3:49 I winced at the "LED Light Bulb" bit.
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  8. I don't know about the UK, but in the U.S. stupid refers to an inability to think clearly or logically, or at all. Knowledge cannot "fix" stupid any more than shoving data into a computer makes the computer smart. That being said, knowing how to think is a learned behavior, and some people never learn. But learning how to think makes you less-stupid.
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  9. Yes, DC current flows negative to positive. The power source creates a "surplus" of electrons at one end of the power source (e.g. a battery). The surplus will "flow" to wherever there's a deficit at which the voltage can overcome the resistance.
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  10. Because all of the circuit must pass through the resistor, it will always have a cumulative effect on the circuit. So, it does not matter where the resistor is. Think of the water in a hose... you can kink the hose anywhere along its length and the water will stop flowing.
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  11. He said it in the vein as "1100" is "eleven-hundred".
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  12. Think of a hose filled with water. If you push more water into one end of the hose, the force will carry across all of the water until the other end of those, when some water will be pushed out. Most of us connect empty hoses which fill with water as they're used, but electrons are in everything, so an electrical conductor is always "full". The electrons don't necessarily physically "knock" each other. Remember that electrons are not a discrete particle around the nucleus but instead a "cloud" of where the electron could be. Also remember that like charges repel, so two electrons wouldn't have to touch to repel each other. It is that force of "repelling" which actually is all the work.
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  13. "Basic" means in terms that lay people can understand. It does not mean knowledge everyone does understand. This video contains a very basic explanation of how electrons around an atom work without a thorough lecture and understanding on quantum mechanics. It's enough to explain the basic idea in a manner people can relate to without muddying up with mundane details. That's what "basic" means.
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  14. They're not. Think of it as they just don't travel as far.
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  15. They are all aspects of the same thing. A 9 volt battery has a potential difference of 9 volts across its terminals. If you take two 9V batteries, the negative terminals are both 9V and so would have zero potential difference between them. Voltage is the difference between electric charges or electrical potentials. Using the water analogy, voltage is the similar to the pressure of the water inside a hose. If you connect two hoses to a valve and pressurize the water in the hoses on each side of the valve to the same amount, there is zero pressure on the valve. If you open the valve, no water will flow. Electromotive force is the force of nature acting to convey an electric charge. It refers to the force itself, such as the plunger being pushed into a hose to increase pressure on the water in the hose, or the force of the pressurized water on the closed valve in the previous example. The force is measured in volts. If there is no voltage, there is no electromotive force.
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  16. Yes. Grounding one of the conductors is done mostly for safety, as it removes the electrical casual potential for that conductor. In theory, a person could stand on the ground and touch the grounded conductor and not get shocked. (In practice, there can be eddy currents between the earth and the grounded conductor, depending on how the grounding is accomplished, so it would not be wise to do this.) DC current sources can be grounded, too. Sometimes the Earth itself is used as one of the conductors in a circuit, and this is not uncommon with high-voltage DC transmission line systems.
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  17. It's a photo finish!!
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  18. I was hoping he'd use the Long scale. :D
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  19. As long as the circuit path remains intact, and as long as the magnet keeps moving, electricity will flow in the circuit. The incandescent light bulb doesn't actually turn off at 50 or 60Hz because there isn't enough time for the hot filament to cool off and completely stop emitting light. If the filament in the light fails (i.e. the bulb burns out) then the circuit is no longer intact. I advise you to not think of electricity as "energy from the valence electrons" but energy of the electric charge potential. Electrons are not directly converted into light in a light bulb. All materials resist the flow of electricity to some amount; some materials resist more than others. The resistance manifests as heat. The more current flow, or the more resistance to current flow (they are related), the more heat is produced. The filament in an incandescent light is designed to resist just enough so as to create so much heat that it glows white hot, but not resist too much to where it melts or destroys itself. (The metal tungsten is usually used for this purpose.) The resistance creates heat, and the build up of heat creates the light. Any wire can melt or glow if too much current flows through it. This is why fuses and circuit breakers were invented: to protect the wiring from too much current.
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  20. Actually that's because the electric charge running through your body is cooking you.
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  21. You shoudln't let it bug you so much. People simply don't need a degree in quantum mechanics to understand the principles of electricity. Similarly, you surely don't need to be a mechanic to operate a car. This video is a basic presentation that most people will be able to understand.
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  22. See above.
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  23. There are lots of U.S. accents and there are lots of British accents. Some accents are easier to master than others, on both sides of the pond.
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  24. Those pesky valence electrons. Every substance or material resists the flow of electric current. Some substances resist much more than others. One can create materials to resist an exact amount by combining different substances together.
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  25. It should be but it isn't a detail really worth worrying about.
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