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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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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What is the electric field strength of a photon? In $\rm V/m$ or $\rm N/C$? Or its magnetic field in Gauss or Tesla? For visible light, or gamma rays? [closed]
I am thinking of this now because I have been learning about the Schwinger limit (or Schwinger effect)...
Supposedly, a strong-enough electric and/or magnetic field creates a 'nonlinear' effect in the ...
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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 force is zero in a solenoid
This is a question from Young and Freedman's University Physics.
The book's answer says that the electric forces are zero because the wire is electrically neutral, with as much positive charge as ...
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$z$-component of electric field due to a static square loop
I am having trouble finding the $z$-component of an electric field discussed in problem 2.4 of Griffith’s introduction to electrodynamics.
Suppose we have a square loop of side length $a$ carrying a ...
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Using an imaginary conducting shell of infinite radius to calculate capacitance of a spherical conductor
This is a statement from Serway's Modern Physics which I don't understand. It tries to explain capaticance for a single conductor.
Imagine a single spherical charged conductor. The electric field ...
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3
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What is the net macroscopic electric field at any point inside a dielectric?
This question is based on section 4.2.3 of Introduction to Electrodynamics by David J. Griffiths (Third Edition).
Consider a point $\vec{r}$ inside a dielectric where we are interested in finding the ...
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Electric Field Within a Conductor
I was reading Purcell’s text on electrodynamics when I read his argument that in the absence of external forces, there cannot be any electric fields within a conductor for the static situation. My ...
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Confusion on the definition of dielectric permittivity
I don't understand how we're defining the dielectric permittivity, sometimes it's defined as the ability of the material to resist the electric field and sometimes as the ability to permit the ...
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In which direction are the photons of an accelerated electron emitted? [duplicate]
It concerns the case described below (from this question):
I assume that it is possible to set up a double-slit experiment where the particles, say electrons, are accelerated from when they leave the ...
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Why is the electric potential from a positive sphere not negative? [duplicate]
Say we have a positive point charge located somewhere. Then the electric field due to this point charge is
$\vec{E} = \frac{1}{4\pi \epsilon_0}\frac{Q}{r^2}\hat{r} $ , now considering potential is $V =...
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Dipoles as vectors
A triatomic molecule $X_2Y$ has plane structure as shown in figure. Due to difference in electronegativity, charge acquired by each X atom is $q$ and charge on Y atom is $- 2q$. The bond length ...
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Does cutting out the surfaces with no surface charge affect the charge distribution on the remaining parts of a conducting surface of arbitrary shape?
Assume that we have an arbitrary conducting surface being charged positively/negatively. Also, assume that we have extracted charge distribution by solving the Poisson's equation with proper boundary ...
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Total charge within a sphere
Consider an electric field in free space with
$$
\mathbf {D} = -3z\mathbf {a_r} μCb/m^2
$$
I need to calculate the total charge within a 3mm sphere centered at (0,1,1).
I calculate the charge ...
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1
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Surface charge density within a parallel plate capacitor on different voltages
I need a way to vary the surface charge density without changing the electric field. My idea is to use two large conducting parallel plates close to each other in vacuum enclosed in a grounded vessel (...
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