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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Electromagnetsm, isospin, spin-1/2, and the early years of quantum mechanics question
An electron going around in a circular orbit produces a magnetic field because there is a varying electric field.
But the electric field of the electron itself is a spherically symmetrical field.
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Electric field lines properties
I wanted to ask a question. My question is that are the properties of field lines ( number of field lines leaving/entering a point charge is proportional to the charge, field strength between points ...
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About electrostatic pressure in a charged conductor
To calculate electrostatic pressure, force on an area of the conductor is required. So we calculate the electric field due to charges other than those on the small area on the conductor. Consider a ...
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How does earthing a plate of an isolated charged capacitor even work?
If one plate of an isolated charged parallel plate capacitor is earthed, then that plate must have a potential zero after being earthed as that is what earthing an isolated conductor does, but ...
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What's the difference between electrical induction and chemical batteries [closed]
I'm new in physics/chemistry and i'd like to know what's the difference between both of them and how do they affect the electromagnetic field and move electrons. Also I'd like to know how does a ...
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Understanding dielectrics on the basis of induced charge and energy density
Simply, why is the energy density in a dielectric medium = $\frac{1}{2} K \epsilon_o E^2$?
For a simple case such as that of a capacitor with a dielectric medium inside it, to find the magnitude of ...
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Can field effect transistor s channel s varying depletion layers generate electric flux and control output current indirectly
Since magnetic field lines without need of contact attracts iron filing and drag them closer so that magnetic field line remain smallest.same analogy applied to field effect transistor ions in the ...
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Electric field experienced by a charge
We have two charges, say $Q_1$ and $Q_2$.
The magnitude of the electric field $E$ experienced by charge $Q_2$ is:
$$E = \frac{k Q_1}{r^2}$$
where $k$ is Coulomb's constant and $r$ is the distance ...
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Electric field at a point due to dielectric inserted in between a parallel plate capacitor [closed]
Here, I have a parallel plate capacitor with each plate having surface charge density $\sigma$. A dielectric of dielectric constant $K$, is inserted partially between the two plates. What would be the ...
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Charged plasma and ion grid in interaction in ion thrusters
I was just wondering .....
In this Image of an ion thruster, when the positively charged particles pass through the grids, wouldn't they just bombard the negatively charged grid(a fraction of them). ...
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Electric field inside current carrying conductor
Is the electric field inside current carrying conductor changing electric field or it is a constant electric field?
And how this electric field produce magnetic field?
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Thermionic emission
I have a pretty basic question regarding the beam of electrons as a result of thermionic emission.
In an electron gun, the emitted electrons from the cathode become incident at a point on the other ...
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Electric field at a general point for a finite line charge [closed]
I am trying to evaluate the electric field at a general point (not only just along an axis) for a finite length of charge. I am getting a very weird integral and also my attempt failed the sanity ...
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Understanding Symmetries and Invariances in Electrostatic Fields [closed]
I'm currently studying electrostatics and I'm having trouble understanding the concepts of symmetries and invariances of electrostatic fields. I understand the basic definitions of symmetry planes and ...
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Why are fields described as force divided by mass or charge?
I have read that application of force on a body from a distance, like gravitational or electrostatic force is a two-step process, first, the field is created by the body, then, the application of ...
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Capacitance of a dielectric capacitor with two sphere electrodes instead of parallel plates
EDIT: title changed to be more descriptive.
I would like to calculate the capacitance of a material (in plate form with thickness d and a known permittivity $\varepsilon_r$ ) between two sphere ...
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Behavior of the electric field of an incoherent light wave [duplicate]
If I am not mistaken, an incoherent light wave is a light wave made out of waves with random phases: it consist of photons with random phases.
Now I am wondering what we would see if we would ...
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How will the capacitance of a capacitor reduce when the distance between the plates is increased?
Now I know that if the potential difference between the plates increase that capacitance will reduce, but for that also I thought as the distance between the plates increases, the electric field ...
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Potential of circle and $n$-gon
Consider power central fields $f \sim r^k, - \infty < k < \infty$,
and unit circle, "charged" in the sense of the field.
We will be interested in the potential within the circle,
i.e. ...
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Is the voltage a result of the existence of the electrical field or is it vice-versa?
Sorry for my question that may be a bit vague but
In my school book there are these two definitions:
The direct current results from the movement of free electrons so the overall movement be in one ...
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Electron gun; potentials around charged plates
I know that an electron gun releases electrons by thermionic emission and accelerate the electron through charged plates, and that the electrons are not gaining any energy after they leave the gap ...
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Why electric field increase near the cable connected in AC 220V socket even current is zero?
If I put low frequency electric field meter near the connected cable in AC 220V socket, he show 1200 V/m even if device is turn OFF(zero current), if disconnect cable from socket, field drop to 8 V/m.
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How is the index notation for the electromagnetic potentials defined?
I don't understand, how the $\vec{A}$ potential is defined in the covariant formulation of the Maxwell-Equations.
I am using the metric $(+,-,-,-)$.
The electric field (SI-Units) is defined as:
$$
\...
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Work done on a charge inside a homogeneous electric field and changes in Energy of the system
How to understand the concept of work using the following example:
a positively charged particle (with charge $Q$) is placed in between a charged in a homogeneous electric field between the capacitor ...
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Does the geometric shape of the cross-section of an infinitesimally thin conducting charged thread (wire) affect its electric field?
Assume that a solid conducting torus (toroidal ring), with a cross-section of a circle of (minor) radius $r$, is negatively charged. Solving Poisson's equation, we can find the charge distribution of ...
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Diffusion current in semiconductor while applying an electric field
In case of intrinsic semiconductor, while applying an electric field, only drift current should exist, right? As diffusion current is due to concentration gradient. So the electron flow will be ...
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Comparing Electric Potential Energy of two Charges
I do not know what I am missing here and would appreciate a little help in figuring out the flaw in my logic. I have a row of positive charges and a row of negative charges as shown in the image above....
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Electric field outside of a conductor with charge $q$
Suppose that I have a spherical conductor (radius $R$) with a cavity at the center and a charge $q$ inside it. I know that the electric field outside of the conductor will be
$$\vec{E}=\frac{q}{4\pi\...
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Electric field outside a conductor
Say there is a conducting cylinder in a uniform external field. The charges on the cylinder surface will distribute and create a surface charge density.
Is there any reason the charge density would ...
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Textbook question on calculation of potential difference between two points
My textbook has the following question
What is the potential difference between two points that are 50cm and 80cm respectively from a point charge of 2uC?
Unfortunately, the textbook has not taught ...
