What is Conductor: Definition and 811 Discussions

In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electrical current) in one or more directions. Materials made of metal are common electrical conductors. Electrical current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases.
In order for current to flow within a closed electrical circuit, it is not necessary for one charged particle to travel from the component producing the current (the current source) to those consuming it (the loads). Instead, the charged particle simply needs to nudge its neighbor a finite amount, who will nudge its neighbor, and on and on until a particle is nudged into the consumer, thus powering it. Essentially what is occurring is a long chain of momentum transfer between mobile charge carriers; the Drude model of conduction describes this process more rigorously. This momentum transfer model makes metal an ideal choice for a conductor; metals, characteristically, possess a delocalized sea of electrons which gives the electrons enough mobility to collide and thus affect a momentum transfer.
As discussed above, electrons are the primary mover in metals; however, other devices such as the cationic electrolyte(s) of a battery, or the mobile protons of the proton conductor of a fuel cell rely on positive charge carriers. Insulators are non-conducting materials with few mobile charges that support only insignificant electric currents.

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  1. E

    How do electrons move in a conductor?

    I have a positively charged sphere that is connected with a conductor to a negatively charged sphere. Positively charged sphere will take electrons from conductor. Then the end of conductor expierences lack of electrons and take them from the nearest atoms of conductor. When it gets to the other...
  2. R

    Electric Field Between two Parallel Conducting Plates of Equal Charge

    Attached is the subsection of the book I am referring to. The previous section states that the electric field magnitude at any point set up by a charged nonconducting infinite sheet (with uniform charge distribution) is ##E = \frac{\sigma}{2\epsilon_0}##. Then we move onto the attached...
  3. Stephen Bulking

    Can the Electric Field Outside a Conductor Have a Tangential Component?

    Here I am going to include the proof provided by my book. It is quite a splendid explanation, though there are a few key points I have yet to fully understand. If the electric force by the electric field on the charge at the surface of the conductor is conservative (which it is), then why is...
  4. P

    Force on a current carrying conductor

    I am studying the theory of force on a current carrying conductor in a uniform magnetic field, the Force is ## F=ILB##. I am slightly confused here let us say the conductor is placed in the uniform magnetic field ##B##, then if the current is passing through the conductor then that current would...
  5. S

    EMF induced in a straight current-carrying conductor

    An emf is induced in straight current carrying conductor as it moves at at right angles to a uniform and constant magnetic field. My textbook used direction 1 in the image shown to demonstrate this. I asked my teacher if direction two would be possible and he didn't understand me. So I want to...
  6. I

    Connecting Two 30x10mm2 Earth Busbars: Min. Conductor Cross Section

    I have two 30x10mm2 Earth busbars in switchboard, both are placed on insulators, but connected through various parts of switchboard (ground terminal, rails, door, mounting plate...) What is the minimal conductor cross section allowed for connecting this two busbars directly?
  7. Luke Tan

    Charge Inside a Cavity in a Conductor

    Let us say we have a cavity inside a conductor. We then sprinkle some charge with density ##\rho(x,y,z)## inside this surface. We have two equations for the electric field $$\nabla\times\mathbf{E}=0$$ $$\nabla\cdot\mathbf{E}=\frac{\rho}{\epsilon_0}$$ We also have the boundary conditions...
  8. S

    Force acting on a current carrying conductor within a magnetic field

    I am new to this forum, and this is my first post. Please bear with me if my query has any inaccuracies. In the attached figure, a coil is wrapped around the central arm of a flat H-shaped thin metallic plate (such as iron). DC current flows through the coil and magnetizes the arm. At the...
  9. Athenian

    I Energy of Conduction and Valence Band in Opposing Directions

    Recently, I have been studying some solid-state physics and I came across this ##E-k## diagram online. Here's an image for reference to what I am referring to...
  10. R

    Electric field at (0,0) for this charged square conductor

    Can we assume that square charge resembles a sphere shell, and think like electric field at sphere shell's center is 0.
  11. K

    EMF shielding using a conductor

    So I've been trying to figure out how EMF shielding works. More specifically, I've seen videos where placing a metal conductor in front of a circular coil (with AC running through at radio frequencies) apparently shielded anything behind it. After searching online, I repeatedly saw Eddy...
  12. Kharrid

    Induced EMF in a moving Loop Conductor

    I am having trouble figuring out if the circular loop has an induced current. One explanation is ∫ E ds = -d Φ / dt. Since flux = B ⋅ A, a change in the magnetic field would require a change in the magnetic field, a change in the area, or change in direction of either vector. Since none of...
  13. E

    Grounding conductor connected to grounded conductor

    Hello, I’ve been working with electricity for a few years and have a misconception that was recently revealed again to me. I remember asking my teacher this question in school and him not being able to answer. In North American homes (and other buildings), the neutral or “grounded conductor”...
  14. Bilbo B

    Electric potential of a spherical conductor with a cavity

    Summary:: If the conductor is having a cavity and is provided with some charge, with the cavity too having some charge then how the potential will be affected on the outer surface of the conductor. The center of cavity and the center of hollow sphere does not coincide. As if their centers do...
  15. P

    Gauss' law -- Conductor with a cavity

    I really don't understand the theory of the above kind of questions. But from the little theory i understand the Electric field is 0 inside the conductor and all the charge goes to the surface and distributes equally. a. Since the E=0 inside the conductor the point charge distributes outside...
  16. T

    Vector field equality Curl Proof of Moving Magnet & Conductor Problem

    The moving magnet and conductor problem is an intriguing early 20th century electromagnetics scenario famously cited by Einstein in his seminal 1905 special relativity paper. In the magnet's frame, there's the vector field (v × B), the velocity of the ring conductor crossed with the B-field of...
  17. T

    Electric field within the cavity of a hollow conductor polarized by external charges?

    Suppose we have a hollow metallic conductor, just a thin metallic shell forming a large hollow cavity. It is then polarized by electric charges placed nearby externally. The equilibrium electric field must be parallel to the surface normals of the shell, there must be no tangential component...
  18. S

    Why is the Answer C? Electric Field in Conductors

    The answer according to the key is C. I thought the answer would be E since the electric field inside a conductor is always zero. Can someone explain why the answer is C?
  19. funmi

    The EMF induced in straight current-carrying conductor

    Why is an emf induced in straight current carrying conductor as it moves at at right angles to a uniform and constant magnetic filed. By Faraday's law, this e.m.f. is equal to dΦ/dt but I do not understand how a wire cutting a uniform magnetic field experiences a change in magnetic flux . Its...
  20. A

    Resources on non-spherical conductor surface charges

    Hi all, I know qualitatively that charges tend to concentrate on sharp edges of conducting surfaces. I have tried searching online for a mathematical treatment of such a phenomenon, but I cannot find anything that's quite rigorous. I'd appreciate it if someone could guide me towards such...
  21. S

    Correct statement regarding a conductor in a magnetic field

    By using Fleming's Left Hand Rule, I got the force acting on proton is directed upwards so my answer is (d) but the answer key is (a). So the force acting on proton is actually downwards? Thanks
  22. PainterGuy

    B Electrons in a nonmoving conductor and non-varying magnetic field

    Hi, My understanding of quantum physics is very basic. I have read that each electron has its own magnetic field; in other words, each electron acts like a mini bar magnet. I was reading about Lenz's law and an unrelated point started confusing me. I was reading this text about Lenz's law...
  23. Jelsborg

    Electric field of a spherical conductor with a dipole in the center

    In a recent test we were asked to calculate the electric field outside a concentric spherical metal shell, in which a point dipole of magnitude p was placed in the center. Given values are the outer radius of the shell, R, The thickness of the shell, ##\Delta R## and the magnitude of the dipole...
  24. P

    Incidence on a conductor at an angle greater than the critical angle

    I for one don't see how ##\sin \theta_t \gt 1## is possible, even when you extend into the complex numbers. Is there even a way to order the complex numbers? Does he mean to say that the magnitude is greater than 1? Anyway here's my attempt at interpreting what my instructor is trying to say...
  25. kmm

    Potential of a grounded conductor in the presence of an external charge

    If we set the potential at infinity to be zero, we find that the potential of a grounded conductor is V=0. The conductor being grounded has no net charge and produces no external field, so I understand why in that situation we would say the potential of the conductor is zero. However, in...
  26. A

    Calculating the temperature of a conductor from the current through it

    I'm not sure if this is the right place for this but I have a question about the relationship between current through a conductor and the heat dissipated by the material. Given the current, resistance, and specific heat of a material as well as the specific spatial dimensions is there a way to...
  27. Z

    Conductor that has the highest melting point

    Hoping for feedback regarding engineered conductors that has high melting points (>4000C). Does anyone perhaps know of such metallic alloys or conductive material? (please, no 2D/1D materials -- exotic materials/alloys are OK, just has to be able to be made in bulk!) Thank you!
  28. dRic2

    I Periodic electron motion in a perfect conductor using a semiclassical model

    According to the semiclassical approximation, in response to a constant electric field I would get a periodic motion of the electron, like this: The sinusoidal type function is the velocity, while the function that goes to infinity is the effective mass. Thus I was wondering, since ##v## also...
  29. L

    Conductor Temperature Rise, Three-Phase Vs. Single-Phase

    Good Morning, I am not coming up with an answer in my search, could anyone confirm or deny whether a circuit conductor would experience more temperature rise with three-phase current than if the same R.M.S. current was single-phase. Alternating Current, 60 Hertz. If you want to know why I want...
  30. S

    I Is a Copper Conductor Directional?

    Hi, A question has arisen an a hifi forum (sorry) that cables can be directional. I dispute this, as the proposed mechanism is diodes in the crystal structure etc. or the drawing process to crate the strands. Assume that it is 99.9% pure copper (CW004A (was C101)) and forms part of a cable with...
  31. Noelani2306

    Electrical field outside a hollow spherical conductor

    Hello everyone, There is an electrical field inside and outside (at the same time) the spherical hollow conductor when we place positive or negative charge inside, isn't it? I know this is because of the induced charges on the inner and outer surfaces of the conductor. There is no field inside...
  32. T

    Conditions needed for magnetic force on a conductor

    none
  33. I

    Equipotential link conductor

    When the exposed conductive parts (door, protective screen, closing panel, etc.) do not have any devices or equipment fixed on them, the equipotential connection of these exposed conductive parts must be provided using a conductor, minimum cross-section 2.5 mm² as it's stated in IEC (see...
  34. L

    I Question regarding the energy stored in a conductor

    A conducting spherical shell with inner radius ##a## and outer radius ##b##, a point charge, ##+q##, is located at the center of the cavity, inducing ##-q## on the cavity wall and ##+q## on the shell. First, I want to know the potential in different region of this configuration. My thought...
  35. navneet9431

    The Effect of Conductors on Electric Field Lines

    What is true is that the field due to the point charge outside of the conductor will not be able to penetrate the shell i.e. there will be no field due to the external point charge anywhere within the conductor nor in the cavity: the field will be **killed off*& by the charges on the outer...
  36. K

    Magnetic field around a conductor with protons?

    Assuming that you can create a proton current. For example, the current of ionized hydrogen is analogous to a conductor. Question! Will a magnetic field be created around a conductor with a current of protons? By analogy with the magnetic field of electrons in a conductor.
  37. H

    Why Is Capacitance Considered Constant in a Conductor?

    The capacitance C of a conductor is given to be a constant relationship between charge Q and potential V of the conductor given by Q = CV. But how can C be a constant? Because the potential of the conductor will not be a linear relationship of the charge that I add. THe more charge there is on...
  38. K

    Induced charge on a conductor

    Homework Statement Imagine having a conducting sphere with free charge ##Q## surrounded by a spherical shell filled with a dielectric and then a conducting spherical shell with no free net charge. I want to find out the charge induced on the spherical conducting shell by the sphere or by the...
  39. S

    Magnetic field of a hollow conductor in special circumstances

    I know the magnetic flux inside a hollow conductor is zero. Is this also true if the observer is inside the conductor and the conductor is rotating in relation to the observer so that the electrons are traveling in spirals around the hollow center?
  40. T

    What's the derivation in a moving magnet & conductor problem?

    In the Wikipedia page of the moving magnet and conductor problem, it asserts "This results in: E' = v x B", but does not elaborate why. What's the full derivation?
  41. CharlieCW

    Conductor sphere floating on a dielectric fluid

    Homework Statement A conductor sphere of radius R without charge is floating half-submerged in a liquid with dielectric constant ##\epsilon_{liquid}=\epsilon## and density ##\rho_l##. The upper air can be considered to have a dielectric constant ##\epsilon_{air}=1##. Now an infinitesimal...
  42. C

    Floating potential of a conductor in an electrical field

    I'm interested in the following general question: Assume x,y,z is an axes system, and that the y-z plane is occupied by a conductive plate at a known potential V with respect to the earth. Now, a conductive material M of neutral global electrical charge is placed at some distance of the plate...
  43. iVenky

    Surface charge on a conductor due to a charged rod 'q'

    Homework Statement A charged rod of charge 'q' is at a distance 'd' from a perfect conductor as shown below. What's the total surface charge on the conductor? 2. Homework Equations I tried to solve this without equations. The Attempt at a Solution [/B] Basically, as long as there is E field...
  44. iVenky

    I Direction of E field and propagation of wave in a conductor

    We know that skin depth in a conductor is found using the following expression, (Credits: http://farside.ph.utexas.edu/teaching/315/Waves/node65.html) Basically, as the wave propagates in a conductor, it's electric field strength reduces and reaches 1/e of it's initial value at the skin depth...
  45. iVenky

    Electrostatic force with and without a conductor in between

    The figure shows a charge q1 exerting a force on a test charge qu. What happens to the electric force when a conductor is placed between q1 and qu (cases 1 and 2)? Does the force still remains the same? I am asking this because I am actually interested in finding what happens to the flux in...
  46. D

    Electrical Conductor is in relation to heat transfer

    Homework Statement One of the two glass panes in each window is coated with a transparent electrical conductor. Why does this coating improve the window's insulating ability? Select one: a. The transparent conductor is black in the infrared, with a low-temperature emissivity of almost 1. b...
  47. L

    I What's the correct argument for why E=0 inside a conductor?

    Hi, I thought that I understood why, once the free charges stop moving, ##E=0## inside a conductor, but I really don't. Can someone please help me out? I've heard the following arguments, but I don't think I understand any of them: I don't think ##q=0## implies ##\vec{E}=0##. I understand that...
  48. B

    I Confused about the boundary conditions on a conductor

    In the textbook (attached image) it says that the boundary condition is V=0 at r=R. This creates a correlation that ##B_l=-A_l R^{2l+1}## but the potential at any boundary is continuous so when we take this account, we get. ##B_l=A_l R^{2l+1}## These two clearly contradict each other. I'd...
  49. B

    Electric Field and Potential in a conductor

    So in my textbook (Introduction to Electrodynamics by Griffiths) it said that inside a conductor, the electric field E would have to zero, since if it wasn't the free charges would move accordingly and create a electric field that cancels the original field. But in a question that soon followed...
  50. M

    Sensing current in a conductor

    If I have 120 vac power cord and I wrap a coil around one of the conductors, will a current/voltage be produced in the coil? If so what are the equations that could be used to characterize this arrangement? I.e., how many coils, what size wire, etc. To produce a certain voltage in the coil?
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