Questions tagged [electron]

Anything related to the behavior and properties of electrons, i.e. the elementary subatomic particles accounting for electrical conduction in most solid materials, especially metals.

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26 votes
13 answers
36k views

Is voltage the speed of electrons?

Current is the amount of electrons passing through a wire. Can we say that voltage is the speed of those electrons?
23 votes
8 answers
6k views

In which direction do electric signals flow?

We know that electrons move from the negative to positive terminal, and that holes flow in the conventional direction of current - from the positive to negative terminal. I've always assumed that this ...
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22 votes
3 answers
46k views

How does data travel inside a wire?

I know this is a very basic question but the answers returned by google are way too complicated for me to understand. I am not asking about modulation here. What I want to know is what exactly is ...
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21 votes
9 answers
30k views

How is the internet able to transmit data so fast?

I'm not sure if I'm in the right place or not, but I figured someone here could maybe provide a good answer. I want to know how electricity is able to flow so fast. For example videos games nowadays, ...
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15 votes
4 answers
1k views

Why don't most electrons hit the anode in a cathode ray tube or electron gun?

In a cathode ray tube or electron gun, electrons liberated from the cathode by thermal emission accelerate towards a ring-shaped anode, from the potential difference between cathode and anode. If an ...
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10 votes
4 answers
3k views

Does current flow on an open transmission line?

Please take a moment to look at the diagram below: The question is if the lightbulb will momentarily flash when the switch is closed. I think it will but I get the feeling I am wrong. The reason why ...
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10 votes
4 answers
5k views

Flow of holes in transistor?

Bipolar transistor are said to have both electron flow and hole flow. Movement of electrons can be understood, but holes are fixed part of the atomic/crystal structure. How can we characterize their ...
  • 681
9 votes
4 answers
3k views

Flow of electrons in a wire

Electricity is "flow of electrons". My child asked me if this is so, then ultimately the copper wire should disappear/vanish/finish because the matter is moving from one place to the other. I am not ...
8 votes
7 answers
3k views

Transistor - Why does amplification happen before the transistor and not after?

I know this is a noob question but I just can't find an answer for it on google search results. Well my question is basically this: How come the amplifying occurs before the transistor [red line] and ...
8 votes
4 answers
2k views

Free Electron in Current

An electric current is a flow of free electrons. Are these free electrons totally free from the orbits of metal atom or they moving by jumping from one orbit to another orbit of the atoms? If they ...
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7 votes
4 answers
7k views

Antistatic mat , how it works?

I have a large anti-static mat lying on the table of my workdesk, which looks like this. And it's connected to ground through the wall outlet from one point, meaning it's an open-loop: Let's say I ...
7 votes
6 answers
27k views

Why do electrons flow from a lower potential energy to a higher potential energy?

So I understand that the term "voltage" refers to the potential energy difference between two points. So, in a 5v battery, there is a 5v difference between the positive and negative ends. When these ...
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7 votes
1 answer
594 views

Can a floating capacitor terminal be used to collect electrons?

I want to collect charge from an electron beam source. For that, I'm proposing to put a floating capacitor with its bottom terminal floating and directly exposed to the electron beam gun. The top ...
6 votes
6 answers
6k views

How can electricity be positive when electrons are negative?

I don't understand how can a for example a battery be positive charged when the electrons are negative charged? I've read that protons are positive but they can't move so are all electricity negative?
6 votes
3 answers
961 views

How do electrons carry thermal energy in Peltier coolers?

I've read that when electrons enter from metal to semiconductor type N, they gain thermal energy and make that side cooler and the reverse happens when they leave semiconductor to the conductor. Why ...
6 votes
3 answers
6k views

Why does current have to return to its source in a circuit?

As far as I know there should be a current when a high potential point is connected to a low potential point, but apparently that is not true. I understand that a circuit must be closed in order for ...
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5 votes
4 answers
2k views

What actually happens to electrons in a circuit when work is done at a component?

As the title. Between when voltage is higher; before the electrons reach the component, and afterwards.
  • 107
5 votes
3 answers
294 views

How does current turn to heat/light? [duplicate]

When resistors are serially connected, the current is the same through the whole circuit. To my knowledge, the electric current is electrons traveling. Also, the power of the generator equals the ...
  • 53
4 votes
8 answers
3k views

Is there a mnemonic to remember direction of current flow?

I have always stumbled when remembering which current flow notation to use. In my mind, it's by default conventional current flow. But, I also have in mind electron flow notation. Do you know of a ...
  • 1,813
4 votes
2 answers
1k views

Protons and DC circuit

In a metal wire, do protons flow in the opposite direction from the positive terminal, like electrons do from the negative terminal towards the positive terminal?
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4 votes
4 answers
9k views

So which direction do electrons really flow?

As I understand it, electrons (which are negatively charged) flow towards positive. As a convention, we say that current flows from positive to negative. Is this to say that what you connect the ...
  • 611
4 votes
2 answers
472 views

Why is electron flow taught in some contexts? [closed]

The standard as I learned it is that the flow of current is from positive voltage to negative voltage. The direction of current flow is opposite the direction of electron flow. This is what I learned ...
3 votes
2 answers
519 views

A question about electrons, charges and current

Let's talk about DC, a very simple circuit: a light bulb and a battery. Some authors say that electrons move from negative to positive and current from positive from negative. I always thought ...
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3 votes
2 answers
772 views

Can electron microscopes record video of electricity?

Since electron microscopes capture electrons, can they be used to capture electrons moving in a circuit, and have they been used for this?
3 votes
4 answers
6k views

Does the resistor have to be before or after the component [duplicate]

I am an electronics beginner and I created a small little circuit, just a battery a resistor and a led, then to ground. This is the circuit: simulate this circuit – Schematic created using ...
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3 votes
2 answers
93 views

How do receiver circuits differentiate between carrier/signal waves?

I've been told and shown that a receiving antenna will pretty much pick up any signals around itself. You can then filter out the frequency you want in order to do something with it. What I don't ...
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3 votes
7 answers
14k views

Positive vs negative, power vs ground, flow direction

I'm getting very confused about the inconsistency where some people say ground is always negative, and some say ground is always positive. And some would say, electrons travel from the power source to ...
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3 votes
4 answers
2k views

Does free electrons from the conductor itself flow or electrons inside the battery flow?

I am new to electronics. I read electricity works this way: some atoms have more electrons than protons. These free electrons flow through a conductor such as a copper wire. However, to induce flow of ...
3 votes
2 answers
423 views

Electron Flow Confusion

Using conventional notation in the diagram below, I understand that the circuit is not complete because the diode is in reverse bias. But knowing that the electrons actually flow from the negative to ...
3 votes
2 answers
432 views

How does an electron beam move in XY mode?

I was recently observing some Lissajous figures on an analog scope in XY mode . I was wondering how does the electron beam move . I know it should move from left to right but I find it difficult to ...
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3 votes
2 answers
79 views

Fermi level of metal

Do metals have fermi level? As we know conduction band and valence band are overlaped for a metal. Does it make any sense for metals to have fermi level?
3 votes
2 answers
312 views

How can electrons in a tungsten filament release infrared light photons?

I have a question regarding electric circuits, specifically when it comes to converting electromagnetic energy into light in a light bulb (tungsten)filament. How can an electron in a tungsten atom of ...
3 votes
0 answers
299 views

How is it that two electric currents can travel in opposite directions on the same wire, at the same time, without interfering with each other? [duplicate]

An Introduction to Information Theory: Symbols, Signals and Noise, by John R. Pierce, says the following: While linearity is a truly astonishing property of nature, it is by no means a rare one. All ...
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2 votes
2 answers
2k views

If an electron has 0 electric potential after passing through a resistor, how does it flow to the other terminal

If an electrical circuit only contains 1 resistor, and electron's potential difference (voltage) before and after passing through a resistor is equal to the e.m.f, how does the electron have potential ...
2 votes
4 answers
1k views

How is current the derivative of charge

If electric current is the time rate of CHANGE of charge. Then if I have a DC fixed current flowing into a resistor, same amount of charge is always flowing to that resistor, hence the derivative of ...
2 votes
3 answers
749 views

Do electrons flow from higher to lower or lower to higher potential?

I have seen countless sites saying electrons flow from higher potential to lower potential, but then again I have seen many saying that electrons flow from lower potential to higher. I have always ...
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2 votes
2 answers
116 views

At what acceleration will electron flow be disturbed?

Came across a question regarding max G force that electronics can withstand, and immediately wondered at what speed/force will the electron flow be disturbed, and/or stopped. I might not be thinking ...
2 votes
3 answers
2k views

Why does a p-type conduction band have higher energy then n-type conduction band in a p-n junction?

In an energy band diagram that represents the p-n junction (during equilibrium) the p-type conduction band has greater energy then an n-type conduction band. Why does the p-type have greater energy ...
2 votes
1 answer
237 views

Is there a limit on the charge that can flow in a wire?

I assume when I hook up a 12V battery to a wire, all the free electrons in the wire move. If I hook up 24V, they move faster so more charge passes a area cross section for i=C/s. But in AC, their ...
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2 votes
4 answers
591 views

How do capacitors in series work?

If capacitors are connected in series with a vltg source, then how would each plates get the polarity? For a single capacitor, the electrons from one plate are pumped by the source towards the other ...
  • 23
2 votes
2 answers
7k views

Why is CMOS fall time faster than rise time?

I've just started a computer architecture class, and the slides from a lecture says that the reason why fall time is faster than rise time is that the NMOS electrons have more mobility than PMOS which ...
  • 123
2 votes
1 answer
129 views

Why is there no shot noise in conducting wires?

Why is there no shot noise in conducting wires, while it is present in junctions and barriers like PN junction? Is electron flow not quantized in wires? If it is, why do a resistor and perfectly ...
  • 23
2 votes
2 answers
59k views

Is ground (GND) possitive or negative? [duplicate]

I have been researching the electron flow which goes from negative to positive in a battery. Since ground the returning point in a circuit, shouldn't ground be the positive terminal?
2 votes
2 answers
283 views

Why do electrons move as if on conveyor belt in a circuit?

For example sometimes people will ask whether it matters what side of a component you place a resistor on. Surprisingly, it doesn't matter because electrons behave as if they're all connected together ...
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2 votes
6 answers
3k views

Can vacuum be used to store flowing electrons?

Since electricity can flow through vacuum can it also be used to store electricity? Though it wont remain a vacuum in strictest form.
2 votes
2 answers
5k views

Number of electron with a current of 1A

i'm reading a book that it says : If a current of 1A flows through a copper wire, the number of electrons flowing by a cross section of the wire in 1s is equal to : 1A=(1C/1s)(electron/-1.602*...
2 votes
2 answers
269 views

Calculation for the distance between maximum swings in the drift distance of electrons

I am currently studying the textbook Practical Electronics for Inventors, Fourth Edition, by Scherz and Monk. In section 2.4.1 Applying a Voltage, the authors have written the following: In the case ...
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2 votes
3 answers
841 views

Why the earth attracts charge and where does the charge go when it goes into ground?

Self-explanatory question but to add what I know, by this I will also know if I am right or wrong. I read somewhere that Earth is positively charged, but is not the state (whether positive/negative) ...
2 votes
0 answers
164 views

What does the fermi-level increase in reverse-bias?

Fermi-level tells us the probability of finding an electron at 50%. When you look at an energy band diagram in reverse-bias you can see the Fermi-level increases in the p-type semi-conductor. Why does ...
2 votes
0 answers
50 views

In an energy band diagram why is the valance band in the p-type have more energy then n-type?

I am having trouble understanding energy band diagrams. In an energy band diagram of a semi-conductor during equilibrium the valence band of the p-type is higher then n-type meaning electrons in the ...