Questions tagged [electric-fields]

For questions that utilize the concept of electric fields (commonly denoted by the letter E), or for questions whose answers likely involve electric fields. More specific than the [electricity] tag, as questions about the phenomenon & theory of electricity do not necessarily involve the discussion of fields.

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Electrostatic Potential using Poisson equation

I'm stuck in the following problem. Having in mind an electrochemical transistor, the situation that we consider is a one dimensional electrolyte with non-uniform concentration of ions (with charge q)....
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Can Gauss' Law apply to an irregular 3D region?

Let's say I have this configuration: The figure above is a cube with a charge not in the center. Can I calculate the flux through the surfaces using Gauss' Law, or does it only apply when the charge ...
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Besides the curl is there any other difference between an electric flux line and a magnetic flux line?

As far as I know, both types of flux mediating the electromagnetic phenomenon and related forces consist of coherent streams of virtual photons according to the known theory. Besides the total non-...
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Does movement of a charged particle in a electric field imply electric potential energy?

A particle at rest with charge $q$ and mass $m$ is placed in the center of a spherical shell with surface charge $-\rho_s$ on the top half and $\rho_s$ on the bottom half (see image). The particle ...
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Electrostatic Potential and Field for an Infinite Conducting Plane with Charges on Both Sides

Suppose that we have an infinite conducting plate that occupies the $x-z$ plane. We put 3 point charges $q_1 = Q,\quad q_2 = Q$ and $q_3=2Q$ in the points $(0,a,b),\quad (0,a,-b)$ and $(0,-a,0)$ ...
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What is the electric field strength required to rip apart particles

Water is a polar molecule, one side slightly positive and the other slightly negative. Would it be possible to rip a water molecule apart into hydrogen and oxygen gas using charged parallel plates ...
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Do Electrostatic Charges build up at the ends of an Inductor in closed circuit?

I was watching this video from YaleCourses youtube channel. At around 41.00 minutes, the professor introduces the notion of charge buildup at the ends of an Inductor in a closed circuit. Is the ...
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Why does electron stop accelerating after passing anode in Cathode ray experiment?

This same question was posted on quora and what I found out there that there is some graphite coating around the anode extending to just before the florescent material. This graphite coating is ...
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What keeps a light wave 'waving'? [closed]

Why does the a light wave crest, rather than continuing off in the direction it's heading prior to the moment it begins cresting? What force/acceleration/thing 'turns' the wave towards the bottom (or ...
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Electric field in a rod rotating in a magnetic field [closed]

Recently I came across a problem: A metal rod of length $L$, connected to a vertical shaft is rotating in a horizontal plane with a constant angular velocity $\omega$ (anticlockwise as seen from ...
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How does current behave in a piezoelectric circuit?

I am trying to understand the fundamental principles of piezoelectrics, but my searches haven't helped me answer this question. As I understand it, squeezing a piezoelectric causes a mechanical ...
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What is the electric field at a distance $r$ due to an infinitely long wire carrying a constant current $I$?

We know that an electric field in terms of potentials is given by $\overrightarrow{E}=-\overrightarrow{\nabla }\phi -\dfrac{\partial \overrightarrow{A}}{\partial t}$. But I just came across, while ...
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How to argue that the potential is the same in a conductor with zero resistance when we have electricity?

I am wondering how we can argue that the electrical potential is the same in point A and B in the figure below: I have seen the argument that in a conductor where the charges are not moving, then the ...
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Charging a metal by extracting electrons from it? [duplicate]

Suppose we have a field emission electron gun as shown in the figure, (let's ignore the voltage of the second anode), the voltage of the first anode is to extract electrons from the cathode, there is ...
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Why is there an electrostatic field in a closed current?

There is something about the derivation of the formula for parallel resistors I can not understand($1/R_t=1/R_1+\cdots+1/R_N$). In order to derive this formula we use that the potential is the same ...
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Electric displacement - why are field lines continuous?

I recently attempted problem 4.17 in Griffiths's "Introduction to Electrodynamics" 3rd edition in which you are asked to make a sketch of the electric displacement vector D in and around a ...
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In applications where heating is not the required from of energy, current is to be kept low as per Joules law. What energy is considered useful?

As per this paragraph from Wikipedia "Joule heating is referred to as ohmic heating or resistive heating because of its relationship to Ohm's Law. It forms the basis for the large number of ...
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Does the fields of any other fundamental force beside electromagnetism display duality?

I've always found the duality of the electromagnetic force intriguing: Why does it seem to have two distinct facets in the static case, with Lorentz transformations transforming one field into another,...
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Eletric field inside of a conductive charged spherical shell, which has an inner conductive sphere [closed]

Suppose a charged spherical shell, centered at the origin, with outer radius of $R_0$ and inner radius of $R_i$, and it has charge $Q$. Inside the shell, there is a conductive sphere with charge $q$ ...
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Electrostatic potential resolving singularity

I'm trying to determine the electrostatic potential caused by a specified charge density function: $$\rho_c(\vec{r}) =\begin{cases} 1 & \vec{r} \in V\\ 0 & \text{otherwise} \end{cases}$$ The ...
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Does Electric Flux Density due to an external Electric field increase in a dielectric medium as compared to free space?

There is exactly the same question on StackExchange but I don't find it rigorous or even right per se. How flux density increases in the dielectric medium? In the 7th edition of the book "...
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Electric potential and field lines

I have learned that electric field lines goes from higher potential to lower potential. First of all, how does this happen? And if the above is the case then suppose I have two uniformly positively ...
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How can I find out the electric field in the parallel to the axis of the ring or disc?

In case of ring, at the axis $\ldots$ electric field is $E=kQx/(R^2+x^2)^{\tfrac 32}$ when we assume constant charge density and distance of the point on axis at a distance from centre is $x$. Now my ...
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How does the act of bringing poles closer together increase electromagnetic strength?

According to my textbook, the strength of a horseshoe electromagnet can be increased in the following ways: Increasing the amount of current flowing Increasing the number of turns of the coil ...
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How do dielectric molecules in a liquid phase align when polarized?

As seen in the diagram, when a dielectric material becomes electrically polarized, the molecules align themselves in a manner where the respective charges are parallel to each other horizontally. ...
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Does electric field really exist or it is just an interpretation? [duplicate]

Did physicist create the concept of electric field to describe the interaction of charge particles at a distance? If they are real, do we have experimental evidence? Please describe some of them. And ...
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Electric field for material with different dielectric constant

I was reading some papers where people calculate the electric field of charges sitting at the interface between two different mediums, with different dielectric constants, $\epsilon$ and \$\epsilon_{...
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Rationale for the Electrostatic Field

This is from div grad curl and all that, h.m. schey. By trivial the author, I think, just means dividing the electrostatic force by the test charge to get the electrostatic field. What I need are ...
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I am trying to understand how electricity works on quantum level. Precisely how is energy actually transferred from generator to the consumer. Here is what I managed to understand so far by reading ...