Conductor Definition and 820 Threads

In a conductor, excess charge resides on the surface. That seems odd, because one would think that the overall energy of the system could be lowered by allowing some of the excess charge to move inward and away from all the charge on the surface, but obviously that can't be true, because charge...

Please help

Let's assume that I have have one conductor carrying current to the load in one direction and the return line with current in the opposite direction from the load. If the current has high di/dt due to switching, may have EMI issues with nearby circuits. I know that I can put a "ground" plane on...

Assume that a certain charge distribution ##\rho## generates an electrical field ##E_{ext}## in the surrounding space. We also note the corresponding generated potential ##V_{ext}##. Assume furthermore that a conductor A, with a definite shape and volume, is placed in field ##E_{ext}##, and is...

Summary is from abstract in Nature. Anybody know whether this is a big deal ?. It looks technically challenging (very high pressure) but great oaks from little acorns. I'm not current in superconductivity.🔎...

This is not a homework question but something that bugs me a bit. My professor has stated that the electric field inside a conductor is 0. This I understand. However, he has also said that even if the conductor has some hole in it, the electric field inside this hole is also 0 Now, two...

How many electrons can you remove from a solid substance before it breaks down at a chemical level? Thinking this through myself, you can create positively or negatively charged objects to a degree, especially with a metallic conductor that can tolerate a loss of charge at the cost of the...

It is not a direct home work problem, i was thinking if a sine wave current passes through the straight current carrying conductor, what will be the magnetic field. For the DC current I know the formula as below. ##B = \frac {\mu_0 I 2a} {4\pi x\sqrt{x^2 + a^2}}## Let the current be ##I =...

I have two charged spheres connected to different ends of an infinitely long conductor. The first sphere has positive charge, another sphere has negative charge. Suppose that the electric field of the first sphere at point A is zero, and the electric field of the second sphere is zero at point...

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...

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...

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...

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...

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...

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?

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...

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...

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...

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

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...

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...

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”...

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...

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...

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...

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...

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?

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...

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...

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

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...

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...

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...

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...

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...

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!

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...

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...

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...

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...

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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...

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...

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...

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.

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...

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...

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?

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?

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...