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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Rotation of electric field vector or polarization
Given a circularly polarized light field. I am using complex notation to represent the field,
$$\vec{E}(z=0, t) = \frac{1}{\sqrt2} [ \hat{x} (\cos(\omega t) - i \sin(\omega t)) + \hat{y} (i\cos(\omega ...
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How does electric potential vary between two positive test charges? [closed]
If you plot a graph showing the variance of electric potential between two charges, does the middle have a maximum or minimum electric potential and why?
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How exactly do charged capacitors decrease current?
I recently learned about how capacitors function in electric circuits, and I came across an apparent contradiction that I wanted to ask about. On one hand, I know that as charge builds up on the ...
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Why am I getting Work done as negative in bringing a positive charge near another positive charge? [duplicate]
Let us consider a charge $Q>0$ at origin. Let $P(r,0)$ where $r>0$ be on $X$ axis.Consider a point $M(x,0),\:x>r$ from which we have to move a charge $q>0$ towards point $P$.
Now I am the ...
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How is the $E$ field at the surface of a charged rod affected by its dielectric constant?
I am seeking clarification on a concept from a test question I have been studying.
Essentially, the question gives an example of an infinitely long charged rod, made of an insulating material. The rod ...
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Will an off-center charge inside a conducting shell experience a force, or is the force zero? [duplicate]
I have a fundamental question about the force on a charge inside a conducting shell that I can't resolve.
The setup:
Take a hollow, spherical conducting shell (it can be charged or uncharged).
Place ...
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Feynman lectures, relative electric field
Both pictures are from Feynman Lectures, vol2 chapter 26, and are talking about the relative electric field.
In the first picture, equation 26.6 says that Ex(electric field in the x direction) of the ...
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I don't understand when electrical field is non-conservative when calculating the electromotive force
So from what I've gathered emf is given by $\epsilon=\int_C (\textbf{E}+\textbf{v}\times \textbf{B})\cdot\textbf{dl}=-\frac{d\phi}{dt}$ where $C$ is a closed loop and $\phi$ is the magnetic flux ...
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Why is polarization $\mathbf{P}$ proportional to the $\mathbf{E}$ field, but magnetization $\mathbf{M}$ proportional to the $\mathbf{H}$ field?
Why is the polarization intensity $\mathbf{P}$ proportional to $\mathbf{E}$ (electronic filed), while the magnetization intensity $\mathbf{M}$ proportional to $\mathbf{H}$ (magnetic filed), when the ...
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Confused about the reason why real current inside a battery flow opposite to the electric field
I've learned that the electric field points from the positive terminal (higher potential) to the negative terminal (lower potential). Since the force on an electron would be opposite to the field, ...
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Successive image charge method
Given 2 plates separated by the distance $d$, grounded and a point charge $Q$ between the plates from the first plate by a distance of $x$. We have to find the net charge on both the plates.
The net ...
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If electrons move slowly, then why does the electric field inside a conductor become zero instantly?
In electrostatic conditions, if an external electric field is applied and there is a solid conductor in the electric field, the electric field inside the conducting material is said to become zero ...
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Griffith, Electrodynamics, 4th Edition, Example 4.8. (Second part)
P.s. This post is a continuation from Griffith, Electrodynamics, 4th Edition, Example 4.8. (First part). I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8. I want to understand ...
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Griffith, Electrodynamics, 4th edition, Example 4.7
I am reading the Example 4.7. in the Griffith's Electrodynamics book and stuck at some statements.
Example 4.7. A sphere of homogeneous linear dielectric material is placed in an otherwise uniform ...
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Feynman's approximation of electric field far away from a moving charge
Feynman in his lectures, Vol 1, chapter 28 gives formula for electric field at point $P$ which is generated by a moving charge $q$ as
$$E = \frac{-q}{4\pi\epsilon_0}[\frac{e_{r'}}{r'^2}+\frac{r'}{c}\...
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