It has little to do with the separation of opposite charges. And though electric current really exists and electric charge really exists, there is no such material as either "current electricity" or "static electricity. Most textbooks discuss a substance or energy called "current". They constantly talk about flows of current. Is it water, or is it "current? The same idea applies to electricity: electric current is a flowing substance, but the name of the substance is not "current.
Another question: what if the English language had no word for "water", but instead we called it "current"? What if we really believed that rivers were full of "current" which flowed? Wouldn't people tend to acquire many serious misconceptions about the nature of water?
We might imagine that it vanishes whenever it stops flowing, since a halted current is A glass of water would seem very confusing, since the glass would be full of stationary "current.
As far as elementary textbooks are concerned, we have no name for the stuff that flows inside of wires. The stuff, when it flows, is properly called. Refer to advanced physics texts, and there we'll find its correct name: Charge. Instead they say that "current" flows. They say it over and over and over, and any students are very lucky if they avoid picking up the wrong idea that the charges vanish when the flow is halted.
Does the water in a pipe suddenly evaporate when you halt its flow? Worse, most books say that "current electricity" flows in wires. To this I say, "Is there a special kind of water called 'current water? The same answer applies to electricity: electricity can flow and electricity can stop, and a flow of electricity or charge is called an Electric Current, but there is no such thing as "current electricity.
If the sentence states that charge-flow is flowing, then that particular sentence is confusing the students and teaching them to believe that a substance called "current" exists. Electric current is actually a flowing motion of charged particles. The words "Electric Current" mean the same as "charge flow. On the other hand, electric energy is different. It is made of waves in electromagnetic fields and it moves VERY rapidly.
Electric energy moves at a different speed than electric current, so obviously they are two different things flowing in wires at the same time. Unless we realize that two different things are flowing, we won't understand how circuits work.
Indeed, we will have little grasp of basic electrical science. In an electric circuit, the path of the electric charges is circular, while the path of the energy is not. A battery can send electric energy to a light bulb, and the bulb changes electrical energy into light.
The energy does NOT flow back to the battery again. At the same time, the electric current is a circular flow, and the charges flow through the light bulb filament and all of them return to the battery. In a single wire, electric energy can even move continuously forward while the direction of the electric current is alternating back and forth at high frequency.
Here's one way to clarify the muddled concepts: if electric current is like wind, then electrical energy is like some sound waves, and electrons are like the molecules of the air. For example, sound can travel through a pipe if the pipe is full of air molecules, and electrical energy can flow along a wire because the wire is full of movable charges.
Sound moves much faster than wind, correct? And electrical energy moves much faster than electric current for much the same reason. Air in a pipe can flow fast or slow, while sound waves always move at the same very high speed. Charges in a wire can flow fast or slow, while electrical energy always flows along the wire at the same incredibly high speed.
Whenever sound is flowing through a pipe, the air molecules in that pipe are vibrating back and forth. When waves of AC electrical energy are flowing along a wire, the electrons in that wire are vibrating back and forth 60 times per second. Suppose that we were all taught that sound and wind are the same thing? This would prevent us from understanding wind or sound. They say that electric currents are a flow of energy, as if wind was really sound.
It completely prevents us from understanding both electric current and energy flow. For example, sound can flow inside an air-filled tube, while electrical energy always flows in the space outside of the wires, and does not travel along within the metal wires. However, electrical energy is coupled with compression waves in the electrons of the wire. Electron-waves travel inside the wires, yet the energy they carry is in the invisible fields surrounding the wires.
Is it important for us to realize that wind is not sound? School books would cause harm if they taught us that wind is sound. And if we want to understand circuits, we need a clear view of electric charge flow, and of electric energy flow. We need to be totally certain that they are two different things, and our textbooks teach us the exact opposite!
Some books imply or even state outright that, whenever a battery is connected in a complete circuit, the charges flow only in the wires, and that no charges flow in the chemicals between the battery plates. These books often contain a diagram of a battery, wires, and a light bulb. In any simple electric circuit, the path of the electric current is a complete circle. It is like a drive belit , and it has no starting point. It goes through all parts of the circuit including the battery, and including the.
If there's one Ampere in the wires connected to the battery, then there's also a 1-Amp flow of charge in the electrolyte between the battery's plates. Where does this charge come from? A battery does not supply charges, it merely pumps them. Whenever electric charge flows into one terminal of a battery, an equal amount of charge must flow THROUGH the battery and back out through the other terminal.
The battery is a charge pump. Some books give an analogy with a circular track full of freight cars waiting to be filled with coal.
This picture is wrong too. The energy in electric circuits is not carried by individual electrons. Instead the electrons move very slowly while the electrical energy flows rapidly along the columns of electrons. The energy is carried by the circuit as a whole, not by the individual charged particles.
Here's an analogy which may help explain it: imagine a wheel that's free to spin. For example, turn a bicycle upside-down in your mind. Give the front tire a spin.
When you spin the wheel, your hand injects energy into the entire wheel all at once. Now put your hand lightly against some part of the tire so the spinning wheel is slowed and stopped by friction. Your hand gets hot.
Your hand extracts energy from the entire wheel, all at once, and the whole wheel slows down. Finally perform both tasks at. Would it be right to tell students that the "Power" hand fills each rubber molecule with energy, that the molecules travel to the "Friction" hand and dump their energy, then they return empty to the "power" hand and get refilled? No, of course not! If this were true then the energy would be forced to travel only as fast as the rubber.
Your "friction" hand wouldn't experience any friction until those magically energized rubber molecules made their way around the rim. Part of the wheel would be spinning while part would be de-energized and unmoving, and this would be really a strange sight to see! A flashlight circuit is like our bicycle wheel. The electrons in the copper circuit are like the rim of the wheel.
They are like a drive belt inside the wires. The battery causes ALL the electrons in the loop of wire to begin moving. As soon as the battery moves the electrons, the distant lightbulb lights up.
The electrons moving into the bulb's filament are exactly the same as the ones moving out; the bulb doesn't change them or extract stored energy from them. Did your hand alter the rubber tire as it rubbed on the bicycle wheel?
No, it just slowed the whole wheel down. It extracted energy from the whole wheel, and was heated by friction. Same thing with the bulb, it slows ALL the electrons down throughout the entire circuit, and in this way extracts energy from the whole circuit as it lights up.
In discussing this misconception with teachers, I find that they see nothing wrong with teaching it to their students! After all, the kids instantly grasp the "freight cars with coal" story since it is very visible and it offers a sensible explanation.
What more can we ask? Yet there, is a serious problem here: electrons flow slowly, and in AC circuits they don't flow at all, instead they wiggle. In order to really understand electric circuits in the more advanced classes, a student must UNLEARN the seductive freight-cars analogy. It freezes their understanding of electricity at the elementary-school level. Yes, if the kids will never have any need to understand how electricity REALLY works, then the freight-cars analogy is fine.
The kids can memorize it, teachers can test them for it, and everybody is happy. But if the kids grow up to become scientists and engineers and technical people, then the freight-cars analogy causes them harm. Unfortunately, it only causes FUTURE harm, so the K-6 educators never encounter the negative effects of the misconceptions they've installed in the kids' minds. In that case the freight cars are moving back and forth but not progressing forwards. How can they deliver their coal to the far end of the track?
I suspect that teachers encounter this problem, and rather than recognizing that "freight cars" is a misconception, they instead pile another misconception: the wrong idea that electrons in wires flow at the speed of light. After all, if the coal-filled freight cars traveled INSTANTLY to the far end of the track, then dumped their coal, then traveled instantly back, that would be alternating current.
But electric current is actually a very slow flow of charges, and during AC those "freight cars" only wiggle back and forth a few feet on their tracks. The bicycle-wheel analogy has no problem explaining AC.
Just wiggle the bicycle wheel back and forth instead of spinning it continuously. The wiggling wheel will rub upon the distant "friction" hand, and will heat it up. Energy can essentially travel instantly across the bicycle wheel, even though the wheel itself rotates slowly. Energy can travel instantly between the hands even if the wheel moves back and forth instead of spinning. The "filled freight cars" analogy seems seductively appropriate when used to explain Direct Current.
However, when explaining Alternating Current the analogy breaks down completely. Each freight car wiggles back and forth, so how can those energy-filled buckets move from the "battery" to the "light bulb? The analogy doesn't work, and students who have learned the analogy will find it impossible to understand AC. Again, this is fine if the kids have no hopes of entering any kind of technical career; if their science learning will cease after fifth grade How about an analogy regarding this analogy grin!
How do sound waves work? Ask yourself this. Would it be OK to teach kids that your vocal chords place energy into air molecules, then the air molecules zoom out of your mouth at MPH and eventually crash into the ears of distant listeners? I would think that any author who use this kind of explanation should be ashamed.
Yes, the explanation "works", and it is easy for the kids to grasp. But it is wrong: sound is carried by waves in the air, not by air molecules launched at immense velocities out of your mouth. And any kid who believes this "launched molecules" sound explanation will have terrible difficulties should they ever have need to understand how sound REALLY works. All of this is an analogy for wires and circuits: electrical energy is wave energy; electrical energy moves along the columns of electrons like sound moves through the air, and when electrical energy flows across a circuit, the electrons DON'T flow along with it.
The word "charge" has more than one meaning, and the meanings contradict each other. The "charge" in a battery is energy chemical energy , while the "charge" that flows in wires is part of matter, it is electron particles. And those wires, though full of charge The term "charge" refers to several different things: to net-charge, to quantities of charged particles, and to "charges" of energy. If you are not very careful while using the word "charge" in teaching, you might be spreading misconceptions.
For example, even when metals are totally neutral, they contain vast quantities of movable electrons. So, should we say that they contain zero charge because they are neutral? Or, should we say that they contain a very large amount of electric charge, because they are filled with electrons? Don't answer yet, because your answer might be inconsistent with how we describe capacitors further below.
Another: if I place an electron and a proton together, do I have twice as much charge as before, or do I have a neutral hydrogen atom with no charge at all?
What I DO have is confusion. Misuse of "charge" makes descriptions of electric circuits seem complex and abstract, when the explanations are really just wrong. Another: electric currents in wires are actually a motion of "neutralized" charge, where every electron has a proton nearby. If we teach that a. We could say "Oh, but most electric currents are usually a flow of Uncharged Charge. What would a student make of THAT statement?
Can you see the problems that arise because of the word "charge? Chemical "fuel" accumulates, but charge does not: the charges flow into or out of the surfaces of the plates and do not accumulate there. A "charge" of chemical energy is stored in the battery, but electrical charge is not. And when a battery is being "discharged", it's chemical fuel drives a process which pumps charge through the battery. The fuel will eventually be exhausted, but the total electric charge within the battery will never change!
Here's a way to imagine the process: a battery is like a spring-driven "wind up" water pump. Send water backwards through this pump, and you wind up the spring. Then, provide a pathway between the inlet and the outlet of the pump, and the spring-motor will pump the water in a circle. But now think for a moment: the water is the charge, yet our wind-up pump does not store water!
This causes the chemicals on the battery plates to store energy, like winding up the spring in our spring-powered water pump. See how "charging" and "charges" can create a horrible mess of misunderstandings? When this mess gets into the textbooks and educators start teaching it to kids, the kids end up believing that Electricity is too complicated for them to understand.
Yet the fault does not lie with the students!!!! Another one: if you "charge" a capacitor, you move charges from one plate to the other, and the number of charges within the device as a whole does not change. But capacitors have exactly the same total charge within them whether they are "charged" or not! Whenever we take an electron from one plate, we put an electron onto the other plate. When we speak of "charging" capacitors, we've suddenly stopped talking about charge, and started talking about electrical energy.
This basic concept is very important in understanding simple circuitry, yet it is rarely taught. The misleading term "charge" stands in the way of understanding. I suspect that students are not the only ones being misled. Many teachers misunderstand simple physics, and they believe that the purpose of a capacitor is to store electric charge.
Yet electric charge is the medium of energy storage in both coils and capacitors. In capacitors, energy is stored in the form of "stretched charge", or potential energy, while coils store energy in the form of moving charge which contains kinetic energy. However, we don't put any charge into a capacitor when we "charge" it , any more than we put charge into a superconductor ring-inductor when we give the ring a "charge" of electromagnetic energy.
It appears when two dissimilar insulating materials are placed into intimate contact and then separated. All that's required is the touching. For example, when adhesive tape is placed on an insulating surface and then peeled off, both the tape and the surface will become electrified. No rubbing was required. Or when a plastic wheel rolls across a rubber surface, both the surface and the wheel become electrified.
Intimate contact is sufficient, and no rubbing is needed. Of course if one of the materials is rough or fibrous, it does not give a very large footprint of contact area. In this case the process of rubbing one material upon another can greatly increase the total contact area.
And the heating of the fibers can make the materials even more electrically "dissimilar", which aids the charge-separation process. But this rubbing is not the cause of the electrification. During contact-electrification it is usually only the negative electrons which are moved. As negative particles are pulled away from the positive particles, equal and opposite areas of imbalance are created.
In one place you'll have more protons than electrons, and this spot will. Elsewhere you'll have more electrons than protons, for an overall negative charge. You've not caused a "buildup", you've caused an imbalance, an un-cancelling, a separation. The law of Conservation of Electric Charge requires that every time you create a region of negative charge, you must also create a region of positive charge.
In other words you must create a separation of opposite charges. If you want to call it a "buildup of electrons", then you also need to call it a "buildup of protons," since you can't have one without the other. It doesn't matter whether the region of imbalance is flowing or whether it is still. Only the imbalance is important, not the " staticness. All solid objects contain vast quantities of positive and negative particles whether the objects are electrified or not.
When these quantities are not exactly equal and there is a tiny bit more positive than negative or vice versa , we say that the object is "electrified" or "charged," and that "static electricity" exists.
When the quantities are equal, we say the object is "neutral" or "uncharged. Since "static electricity" is actually an imbalance in the quantities of positive and negative, it is wrong to believe that the phenomenon has anything to do with lack of motion,.
When this happens, it continues to display all it's expected characteristics as it flows, so it does not stop being "static electricity" while it moves along very non-statically! In a high voltage electric circuit, the wires can attract lint, raise hair, etc. A disconnected wire contains charges which are not moving they are static, yet it contains no "static electricity!
To sort out this craziness, simply remember that "static electricity" is not a quantity of unmoving charged particles, and "static electricity" has nothing to do with unmoving- ness.
If you believe that "static" and "current" are opposite types of "electricity," you will forever be hopelessly confused about electricity in general. Electric power cannot be made to flow. Power is defined as "flow of energy. It's as silly as saying that the stuff in a moving river is named "current" rather than named "water.
Talking of "current" which "flows" confuses everyone. The issue with energy is similar. Electrical energy is real, it is sort of like a stuff , and it can flow along. When electric energy flows, the flow is called "electric power.
Electric power is the flow rate of another thing; electric power is an energy current. Energy flows, but power never does, just as water flows but "water current" never does. The above issue affects the concepts behind the units of electrical measurement.
Energy can be measured in Joules or Ergs. The rate of flow of energy is called Joules per second. This makes for convenient calculations. The nucleus is made up of particles called protons and neutrons.
Electrons spin around the nucleus in shells. If the nucleus was the size of a tennis ball, the atom would be the size of a sphere about 1, feet in diameter, or about the size of one of the largest sports stadiums in the world. Atoms are mostly empty space. If the naked eye could see an atom, it would look a little like a tiny cluster of balls surrounded by giant invisible bubbles or shells. The electrons would be on the surface of the bubbles, constantly spinning and moving to stay as far away from each other as possible.
Electrons are held in their shells by an electrical force. The protons and electrons of an atom are attracted to each other. They both carry an electrical charge. The positive charge of the protons is equal to the negative charge of the electrons. Opposite charges attract each other.
An atom is in balance when it has an equal number of protons and electrons. The neutrons carry no charge and their number can vary. The number of protons in an atom determines the kind of atom, or element , it is.
An element is a substance consisting of one type of atom. The Periodic Table of Elements shows elements with their atomic numbers—the number of protons they have. For example, every atom of hydrogen H has one proton and every atom of carbon C has six protons. Electrons usually remain a constant distance from the atom's nucleus in precise shells. The shell closest to the nucleus can hold two electrons.
The next shell can hold up to eight. The outer shells can hold even more. Some atoms with many protons can have as many as seven shells with electrons in them. The electrons in the shells closest to the nucleus have a strong force of attraction to the protons.
Sometimes, the electrons in an atom's outermost shells do not have a strong force of attraction to the protons. These electrons can be pushed out of their orbits. Applying a force can make them shift from one atom to another. These shifting electrons are electricity. Lightning is a form of electricity. Today there exist generally accepted descriptions of processes occurring in an electric circuit. These descriptions are based on a model in which electrons or other charges move inside a conductor.
But such an explanation is not plausible. Electrons are mechanical particles that have mass. They cannot move or push each other at the speed of light. But an electrical signal is transmitted at the speed of light.
Here is a modern explanation of how electrical energy is transmitted in wires. The source creates a potential difference. The potential difference creates an electromagnetic field. This field propagates along the wire on its outer surface at the speed of light this creates a well-known skin effect. So, wire is not a tube with a current inside. The current does not exist at all [1].
There is a common opinion that all electrical systems and all devices must have connection with ground. But at the same time, there are contradictions in the explanations of grounding systems functioning. In these systems, the current enters the earth. But today it is known that it is impossible to find out any traces of this current at distance of a few meters. If so, where does the current go? There are many attempts to explain these processes.
And all these explanations are different. Some people assume that the earth is a huge capacitor. But, firstly a capacitor should have the second plate. And, secondly, there should be a dielectric inside a capacitor.
But the earth is not a dielectric. Other explanations assume that grounding as current absorption. But absorption cannot be infinite. Any sponge, when it is filled with water, stops absorbing.
There are other explanations as well, but all of them cause new questions. The current which is injected into a ground is divided into a great number of weak currents. When ground depth increases, the quantity of currents grows and therefore the amplitude of each current decreases to zero. Can current flow through broken wires?
Yes, it can, for example, in a linear antenna. In the case of electrical antenna like a dipole or monopole, the current stops at the ends of radiators but its energy converts into the energy of the electromagnetic field. It means that the energy path is not interrupted.
Now we can imagine a grounding or zeroing as a set of very short monopoles. It is known that monopole which height h is much less than a quarter of wavelength has radiation resistance close to zero. Recall that the wavelength at a frequency of 50 Hz is kilometers. This resistance tends to zero as h compared to the quarter of wavelength decreases. Radiation resistance decrease leads to radiating power decrease.
So, we can say that monopole with 5 - 10 m high at frequencies 50 or 60 Hz has zero resistance and zero radiation field density. Note that a monopole with height much less than the quarter of wavelength has a capacitive component.
However, parallel connection of monopoles results in capacitive resistance decrease. In other words, perhaps grounding is a system consisting of a considerable quantity of monopoles, with length much smaller than quarter of a wavelength.
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