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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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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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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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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Coaxial cylindrical conductors electric field in thickness of cylinders
So I want to calculate the electric field at all different locations for the two conductors in the image below.
These are two coaxial thin cylindrical conductors, that we assume to be perfect (so ...
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Infinite charged sheet kicked into motion - Electric field direction?
In volume two of the Feynman Lectures on Physics, Chapter 18, here: http://www.feynmanlectures.caltech.edu/II_18.html
There is a scenario in which an infinitely extending charged sheet is suddenly ...
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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 ...
- 207k
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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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Divergence of Electric Field of Point Charge is always zero [closed]
I might have a bug in my brain, but I just can't figure this out. Please help. According to the first of the Maxwell Equations, we have
$$
\nabla\cdot\vec{E}=\frac{\rho}{\epsilon_0}.
$$
And we have ...
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What happens when both magnetic field and electric field is applied to a charged particle?
Now what exactly happens when magnetic field and electric field is applied perpendicularly? What happens when they are not perpendicular?
In the question, it says that a magnetic field and electric ...
- 207k
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Metallic bonds in Copper and Electric field application
Didnt know where to put this since its like a combination of Chemistry and Physics.
But in the picture below, we can see that they've defined a metallic bond as essentially the attraction between the ...
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Question about electric field around charge density
Suppose the region $0 < x < d$ has charge density $-p$, and the region $-d < x < 0$ has charge density $p$. Why is electric field on the edge of region in point d zero? If negatively ...
- 207k
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Potential on conducting shell without image charge
Edit 2: I know how image charges work. But I'm still trying to rationalize without it.
Edit 1: scrap this, realized what I needed was image charges. This entire question is sort of a jury-rig ...
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Confusion with treatment of unit vectors in electrostatics
I am reading Griffiths’ Introduction to Electodynamics and there are two problems where the methodology for treating unit vectors in integrals seems inconsistent to me.
When we are trying to find the ...
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How high potential difference implies strong electric field around the conductors?
While reading capacitance I found out this statement that for large C, potential difference is small for a given charge means that a capacitor with large capacitance can hold large amount of charge at ...
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Is it valid to write $\int{dq}$?
While I was going through the expression for the electric field in continuous charge distributions (Section 2.1.4) in Griffiths' textbook, it was given as $${E(r)} = \frac{1}{4\pi\epsilon_o}\int{\...
