What is Electron flow: Definition and 41 Discussions

An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume. The moving particles are called charge carriers, which may be one of several types of particles, depending on the conductor. In electric circuits the charge carriers are often electrons moving through a wire. In semiconductors they can be electrons or holes. In a electrolyte the charge carriers are ions, while in plasma, an ionized gas, they are ions and electrons.The SI unit of electric current is the ampere, or amp, which is the flow of electric charge across a surface at the rate of one coulomb per second. The ampere (symbol: A) is an SI base unit Electric current is measured using a device called an ammeter.Electric currents create magnetic fields, which are used in motors, generators, inductors, and transformers. In ordinary conductors, they cause Joule heating, which creates light in incandescent light bulbs. Time-varying currents emit electromagnetic waves, which are used in telecommunications to broadcast information.

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  1. Abimbola1987

    Measurement of vacuum diode electron flow

    Dear Sirs, After my theoretical post on vacuum diode electron flow, I decided to try and measure it physically. I didn't have a vacuum tube, so I improvised with some tungsten wire, aluminum sheets and some screws and the result was usable. Obviously the tungsten wire fails after some time due...
  2. Abimbola1987

    Understanding Electron Flow in Vacuum Diodes

    Dear Sirs I have been going through the "radiotron designers handbook", but I can't seem to find the answer to the doubt I have about the electron flow of the source Vp. Kindly consider the below two circuits, the difference is the polarity of Vf. Question: In both circuits, the electrons...
  3. R

    How to calculate BJT electron flow

    Hello How should i calculate number of electrons passing through it when we apply some gate voltage across it
  4. S

    D-Flip-Flop Circuit: Understanding the Enable and Clock Input Functions

    So I have been watching his videos trying to get ready for second year engineering (electrical). However, I am very confused as to what exactly is going on when he is pressing the enable/pulse switch during the run-through at 14:45. He has the enable connected to a capacitor, and he calculates...
  5. C

    Nichrome and Copper Circuit w/ Electron Mobility

    Homework Statement In the circuit shown, two thick copper wires connect a 1.5 V battery to a Nichrome wire. Each copper wire has radius R = 0.009m and is L = 0.17m long. Copper has 8.4 \times 10^{28} mobile electrons/m^3 and an electron mobility of 4.4 \times 10^{-3}(m/s)/(V/m). The Nichrome...
  6. R

    Understanding Electron Flow in EMF Cells: Anode to Cathode or Cathode to Anode?

    Homework Statement A variable , opposite external potential ## E_{ext} ## is applied to the cell Zn | Zn2+ (1M) || Cu2+ (1M) | Cu, of potential 1.1V . When Eext < 1.1 V and Eext > 1.1V , respectively electrons flow from : 1. anode to cathode and cathode to anode 2. cathode to anode and anode to...
  7. thegreengineer

    Electricity. What kind of current should I use?

    Look, I found that there exist two kind of electric current: conventional flow and electron flow. I have read that in every situation I have to use the conventional flow, however I'm going to work with electric circuits using copper wires. In solids, only negatively charged particles (electrons)...
  8. R

    Speed of electron flow through a conductor

    Is the speed of electron flow through a conductor such as copper equivalent to 'c'? I've heard of this being implied several times, but is it a fact? I know it can't be exactly the same as 'c' because we are not talking of energy propagating though a vacuum.
  9. A

    Does Order of Resistor/LED Matter? Exploring Electron Flow

    Hi, I've been struggling to find the answer to this questions, which are probably simple ones. Does it matter what order a resistor and LED ( or any component ) are in. For example: Vcc -----resistor------Led------gnd or Vcc ------led-------resistor------gnd Are they the same...
  10. S

    Are the electron flow in a conductor and ion flow in electrolyte same?

    A current flow occurs when there is movement of electron in a conductor. But in a electrolyte its the ions that move and we still say there is current flow. Are the electron flow in a conductor and ion flow in a electrolyte is the same?
  11. T

    How Does Electron Flow Correspond to Electric Field Direction in Circuits?

    Homework Statement Sorry if this is not a good fit for this sub-forum but i couldn't find anywhere else to post it. In the physics tutorial http://www.physicsclassroom.com/Class/circuits/topic on current electricty it defines the positive terminal as the high potential terminal and the...
  12. N

    Electron flow in live and neutral wires

    Our Physics teacher used to tell us that in an ac circuit the current and hence the flow of electrons is reversed every half cycle as the polarity of the supply changes every half cycle. However I am still puzzled about the following. In the UK, the live is the wire that delivers electrical...
  13. M

    What can induce electron flow?

    I can think of three ways to induce electrons to flow and generate electricity: 1. Light (i.e. PV cells) 2. Catalyzed chemical reaction (batteries, fuel cells) 3. Magnetic field (turbines -- gas, wind, water, nuclear... everything else I can think of) Mostly turbines. I was wondering if...
  14. T

    Direction of Electron Flow with Real Batteries

    Hello all - a quick question that I can't seem to find an answer to online that I trust... While the conventional current model describes flow of positive charges around a circuit, we know that current is actually the flow of electrons (at least in common metallic conductors). Which leads to...
  15. W

    Kirchhoff Laws: Conventional Or Electron Flow

    Hi, Ive trying to work through Kirchhoffs voltage and current laws. Ive so far calculated: Current in Loop one (I1): 3 Amps going anticlockwise Current in Loop Two (I2): 4 amps going anticlockwise Current in Loop Three (I3): 8 amps going anticlockwise R1: 5 amps going up = (Current...
  16. S

    Electron flow in insulators

    Homework Statement From what we've learned, insulators are not able to allow electrons to pass through or exit through them (beside rubbing/friction). So if I have a negatively charged piece of cloth and move a negatively charged metal rod such that they touch, will they both become neutral...
  17. S

    What makes electron flow in an electrochemical cell

    So, here is my question we know about an electrochemical cell in which when zink rod and copper rod are dipped in there respective solutions the electron flow from zink rod to cu ... but what makes those electron to flow ... here comes the answer the potential difference did that ... please...
  18. S

    Does Higher emf Affect Electron Flow?

    Hello experts! Higher the emf of the battery implies that the higher the drift speed of the electrons or increase the flow time of electrons from the conductor? Which one is true and how??
  19. T

    Automotive How electron flow is in a car system

    Hi, I would like to know how electron flow is in a car system? I ask this because when looking at a car amp install it say connect to the positive terminal, a negative to ground "chassi". I understand conventional flow holes ect, but realistically I can't see how this wiring method works.
  20. P

    Conventional Current Versus Electron Flow?

    I've been trying to get involved in electronics for some time now, but I can't seem to manage to wrap my head around conventional current versus electron flow. I understand that electrons do the movement, but does that mean that electricity flows from the negative to positive side? Or the other...
  21. N

    Electron Flow in Short-Circuited Battery: What to Expect?

    What is the speed of electron flow in an eletric curcuit? A battery (cell) with a copper wire shorted across the positive and negative posts. What will the electron flow be through the copper wire?
  22. H

    What is the relationship between electron flow and the speed of light in a wire?

    I heard that electrons don't travel straight down a wire but that they spiral around the outer part of the wire as they travel down the wire. I know about the skin effect. Is there a name for this spiraling of electrons as they move through conductors? Anyone know where I can find more...
  23. P

    Conceptual question on electron flow between two types of resistors

    Hey, I have a question on resistivity. When I first studied circuits as an undergrad, I just accepted the principle of voltage division and related things they taught us. I now major in condensed matter physics and now having seen the formalism for conductivity in the Drude model and the...
  24. B

    Voltaic Cells and electron flow

    In a voltaic cell, why do electrons flow at all? If I place a piece of zinc metal into a zinc ion solution, nothing happens, right? Likewise if I place a copper electrode into a copper ion solution, nothing happens. When I attach the half cells with something that allows electrons to flow...
  25. B

    Direction of electron flow in solenoid

    I'm having a bit of confusion applying the left hand rule to find the direction of electron flow in a coil. I'm given the following pictures. 1.) To use the left hand rule here, I would wrap my hand around the object with my thumb pointing towards the north pole, so my fingers would...
  26. C

    Calculating Kinetic Energy of Mass Using Electron Flow

    Can anyone tell me what is the best math equation for finding electron flow through mass? I want to determine the kinetic energy of a mass.
  27. K

    Do electrons flow in one direction in magnets?

    Do electrons continuously flow from north to south pole in magnets. If yes, does this continue to happen when the magnet is attracted or repelled by another magnet or to a ferrite?
  28. F

    Electron flow over a conducting surface of variable resistivity

    Hello fellow physics-people, I was just thinking about the following setup: We have a conducting surface (with smoothly varying resistivity) hooked up to some battery with the wires contacting the surface at two arbitrary points, A and B. How would we go about figuring out the current...
  29. Femme_physics

    Electron flow direction: Convention VS what's exactly happening

    [I meant "what's actually happening"]The convention is that the electrons flow from + to - But in reality they flow from - to +I don't get it. Why don't we just mark it like it happens in reality? Why decided to do it otherwise? Isn't it just confusing, esp. to new students?
  30. H

    Conservation of charge and electron flow?

    I am trying to understand the conservation of charge regarding electron flow through a charged body. Is there any thing about the conservation of charge which explains that if a body is charged and electrons leave the body the same amount of electrons must enter it to conserve it's charge...
  31. A

    Understanding Electron Flow in a Wire: Doubts and Explanations

    Hi friends! I know this is a question many people might have posted on the forum. I saw many threads but still have some doubt in my mind, about why do electrons flow in a wire when we attach a battery to it. Being more specific, my doubts are as follows :- (1) My book says that an electron...
  32. M

    Exploring Electron Flow & Mass in Rotating Magnet Sandwich

    The other week I was doing some reading and had a tangential thought about electromagnetism. one thing lead to another and I was revisiting the Faraday Paradox. I will state here at this point this is not a question in regards to over unity or zero-point energy, nor is this a pre-lude to...
  33. C

    Using DC Power to Create Electron Flow in a Tungsten Filament Light Bulb

    If i have a light bulb , and it has a tungsten filament and when i turn it on its gets hot , If i hook a lead to the filament and then put the anode away from the filament can i get electrons to flow through the vacuum , assuming this is done with DC current. If we used 2 different...
  34. R

    What is the direction of electron flow in electricity?

    Hello gurus! I have a novice question. I hope you don't mind me asking this question as it most likely is a very basic question to many. Electrons flow from -ve to the +ve side of a battery. Why then do people also say electricity flows from the +ve to the -ve end? I recall being told...
  35. W

    Engineering Electron flow through basic circuit element

    Homework Statement Given that the current flow is due to electron flow, state whether electrons are entering or leaving terminal 2. i _____ --> | | - -----|1 | v | | + -----|2 | |___| Situation A: V=40V, i=-10A Situation B: V=-60V, i=-10A Homework...
  36. C

    Electron Flow: Positive to Negative?

    I am looking in my differential equations book , and it shows electricity flowing from the positive to the negative , this seems wrong to me , i thought electrons flow away form the negative to the positive , because like charges repel .
  37. Y

    Kinetic Energy and Electron Flow Speed

    I'm learning about electricity and I've stumbled upon a question which I cannot seem to find the answer to. I realize that I am probably missing some key piece of information or making some form of understanding error but just can't seem to grasp what it is. My understanding is that if you...
  38. F

    Electron Flow in Car Batteries: Conventional vs. Electron Theory

    electron/conventional theory - which way does electrons actually flow in a car battery? Ok, I'm confused about what I keep being told when I ask car mechanics about the jumpering of car batteries. I am hoping someone can help me with understanding which way electrons are actually going to...
  39. P

    How does the electric field propagate in a circuit?

    how does an electron 'flow' in a circuit ...can someone please explain me the detailled mechanism ...
  40. R

    Exploring Electron Flow in N- and P-Type Silicon

    When an N-type silicon and a P-type silicon are joined together electrons from the n-type diffuse into the p-type. Now the p-type becomes negatively charges and the n-type positively charged. With forward biasing electrons are forced from the n region into the p region. What is it that makes the...
  41. F

    Electron flow through a wire time

    Homework Statement The electron drift speed in a 1.00 -mm-diameter gold wire is 5.50*10^-5 m/s How long does it take 1 mole of electrons to flow through a cross section of the wire? Homework Equations I=n*q*V*A The Attempt at a Solution...