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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Is there an electric field due to current carrying wire?
In a current carrying conductor with non variable current there is a magnetic field outside but is there an electric field? We take out the magnetic field by biot savart law but how does the electric ...
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Do prisms disperse light by frequency but don't disperse magenetic waves or electric waves on their own in Maxwells Equations?
In a class about EM fields based on Maxwells equations, we learned that when electric field lines cross from medium 1 to medium 2 they obey:
$$\frac{\tan \alpha_1}{\tan \alpha_2} = \frac{\varepsilon_1}...
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Possibility of a system of conductors [closed]
Considering two systems where system S¹ contains even number of conductors and system S² contains odd number of conductors where the total charge on both of the system is positive, in which of the ...
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Definition of the electric field
the electric field is defined as $\vec E= \dfrac {d\vec F}{dq}$ in my text book.
So we are using an infinitely small test charge to probe the electric field.
But why does the test charge have to be ...
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Confusion about bound surface charge density
I am taking a course in ElectroMagnetism and we are now studying electromagnetic fields in matter. We were taught that the total charge is separated into free charge and bound charge:
$$\rho = \rho_b +...
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Why many times $E= -{\rm grad} V$ does not give correct direction of the $E$?
Consider a point charge $Q$ at the origin, and consider two points, one on positive $z$ and one on negative $z$ direction, on the positive $z$ direction the point is located at $(0,0,z)$ and on ...
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Is the electrostatic energy of a continuous charge distribution always positive?
(Griffiths 2.4.3)
The energy of a continuous charge distribution is:
$$
W=\frac{\epsilon_0}{2}\int\limits_{all\ space}{E^2d\tau}
$$
This equation mathematically enforces the fact that the energy of ...
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"Electric Field at the Center of a solid Hemisphere: Where Did I Go Wrong? [closed]
I am currrently studying electrostatics and got stuck in a problem. I am trying to calculate the electric field at the center of a solid hemisphere with uniform charge density. Here is my approach:
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Is my Idea correct? About an electric field applied in a medium?
I think that, when the electric field is applied in a medium then, atoms of that medium become polarised. So, work is done to hold them like that, and energy of the electric field is consumed in this ...
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How is charge distributed in nonconducting materials? [duplicate]
Is it on the surface or disturbed throughout the object ? In derivations of line and sheet , why are the objects considered to be nonconducting?
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How Does Irodov Derive This? [closed]
Potential and strength of the field of a point dipole with electric moment $\mathbf{p}$:
$$\varphi=\frac{1}{4\pi\varepsilon_0}\,\frac{\mathbf{p}\cdot \mathbf{r}}{r^3},\quad E=\frac{1}{4\pi\...
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What is the electric field around a non-current carrying wire?
So that seems like a silly question but I can't quite rationalize something about it.
Electric field in between the plates of a capacitor is defined as E= emf/d.
A dipole antenna acts as a very ...
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Why don't charges on surface of current carrying wire move?
When a steady current flows through a wire, there is usually charges on the surface of the wire. These surface charges have an nonuniform distribution so that the electric field inside the wire is ...
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What is the distinction between neutralizing and screening a charge?
I posted a question earlier about the electrical chage of electrons being neutralized inside an atom by their proxity to the opposite charge nucleous. One comment implied that I used incorrect ...
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What is the intuition behind $\vec{D}$ and $\vec{E}$ not being parallel for the extraordinary beam?
In anisotropic dielectrics, the electric field $\vec{E}$ and the displacement field $\vec{D}$ are no longer necessarily orthogonal. The mathematical reasons are the connection between the two fields:
$...
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