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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Why is the electric field perpendicular to every point on the surface of a conductor?
I am reading Berkeley Physics Course, Volume 2 (Electricity and Magnetism
by Edward M. Purcell). I am in chapter $3$, page $92$, and the book discusses conductors.
The following is from the book:
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Why is the electrostatic force felt in straight lines?
When two positive charges are kept close, they get repelled in the direction of a line joining both the charges. Why is it so?
Also, why is the repulsion in a straight path?
In both the cases, the ...
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Why do we say that electric potential energy is stored in the electric field?
I have been learning electrostatics and came across capacitors. I don't really get why do we say energy is stored in electric field rather than in the charges upon which we or the battery does work. I ...
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Why are the two outer charge densities on a system of parallel charged plates identical?
One of the ways examiners torture students is by asking them to calculate charge distributions and potentials for systems of charged parallel plates like this:
the ellipsis is meant to indicate any ...
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How to show mathematically that the electric field inside a conductor is zero?
The electric field is characterized by the equations
$$\nabla\cdot \mathbf{E} = \dfrac{\rho}{\epsilon_0}$$
$$\nabla \times \mathbf{E} = 0$$
Or equivalently, $\nabla^2 V = -\rho/\epsilon_0$ and then ...
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Does mutual attraction of charged particle violate Newton's Third Law [duplicate]
Consider two particles $A$ with mass $m$ and $B$ with mass $M$ ($M>>
m$), and each particle has charge $Q$. Suppose they are at a distance $r$ ($r$ is of the order $10^{10}m$) apart at a time $...
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Exact relationship between electric field and intensity
I often see $I(t)\propto |E(t)|^2$. What is the exact form ? Which constants are missing to make this an equality and why are they so often omitted ?
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Why we cannot use Gauss's Law to find the Electric Field of a finite-length charged wire?
One of my physics books has a nice example on how to use Gauss's Law to find the electric field of a long (infinite) charged wire. However, at the very end of the example, the author ends by saying ...
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What is the nature of electric field? is it quantized? is it a wave?
What I seek here is to understand whether the electric field in its pure form as in between the electron and the proton is uniform or does it have some kind of wave/particle nature or both, does it ...
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Grounding system of conducting plates
So, I always make mistakes on problems such as this (the grounding part), so I'm hoping someone could really explain to me how the process works.
There are $n$ large parallel plate conductors ...
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Why is electric flux through a cube the same as electric flux through a spherical shell?
If a point charge $q$ is placed inside a cube (at the center), the electric flux comes out to be $q/\varepsilon_0$, which is same as that if the charge $q$ was placed at the center of a spherical ...
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Is electric field inside a conductor really always zero?
The standard explanation in textbooks goes that in the presence of electric field (e.g. external electric field) the free electrons inside the conductor will keep moving until electrostatic ...
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Alternate explanation for energy flow in electricity as explained in this video
The question is about this video from a youtube channel called Veritasium. It is a popular physics/math youtube channel and topics discussed are usually fact checked and accurate.
The gist of the ...
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What is the electric field flux through the base of a cube from a point charge infinitesimally close to a vertex?
I'm having some trouble with the following problem:
A charge $q$ is placed on the body diagonal of the cube very close to one of the corners (distance $\delta$ from the corner, $\delta$ tending to ...
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Current in a simple circuit
I was going over my notes for an introductory course to electricity and magnetism and was intrigued by something I don't have an answer to. I remember my professor mentioning, to the best I can ...
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