All Questions
Tagged with electric-fields potential-energy
21
questions with no upvoted or accepted answers
4
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0
answers
58
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Energy in electric field of an electron?
I am just trying to get an intuition for the Griffiths equation no. 2.45, where work done to establish a field E is given by
Say we want to solve it for electric field due to an electron (point-charge)...
3
votes
1
answer
376
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Coulomb force from a variational principle
See the attached discussion from Zangwill's Modern Electrodynamics, and in particular footnote 9. The point of this question is to understand how to recover Coulomb’s force law from an assumed form ...
- 1,095
2
votes
0
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160
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What should the electrostatic energy of a continuous charge density be?
Hope this doesn't come off as too pedantic or overinterpreted. I've been working on revisiting electrostatic and electrodynamic energy from first principles, and I have the following stumbling block. ...
- 1,043
2
votes
1
answer
109
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what is difference between region around a charge and region out of it?
Basically I want to know what makes a region around a charge particle so affective that another charge will have energy when brought in this region or it will experience a force when enters into this ...
- 309
1
vote
1
answer
122
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The (electrostatic) force on an extended object
It is well known that, if I have a system of $N$ particles acted upon only by conservative internal and external forces, then I can obtain the force on the $\mathrm{i^{th}}$ particle as
$$\textbf{F}_i ...
- 1,095
1
vote
0
answers
133
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Work $U$ required to assemble a charge distribution
I'm reading Purcell's Electricity and Magnetism (p. 72) and it gives an relation between the work $U$ required to assemble a charge distribution $ \rho (x,y,z) $ and potential $\phi (x,y,z) $ of that ...
- 159
1
vote
0
answers
288
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Electric potential energy and work done
My revision notes states that "to move the positive test charge from infinity to point P, the external force provided to that test charge must be equal to the electric force the source charge exerts ...
- 79
0
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54
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Energy in electric field calculated in two different ways
The equation for the energy density in a region of space where there is electric field, $\epsilon_0E^2/2$ implies that energy in the electric field can only be positive. Consider, however, the energy ...
- 49
0
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20
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Using Variation of Energy for a Dielectric to define the Electric Field
I have been reading through Zangwill's Modern Electrodynamics on my own, and I am confused about something in section 6.7.1, concerning the variation of total energy $U$ of a dielectric in the ...
- 1
0
votes
1
answer
435
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Doubt in the interaction energy of the dipole in an electric field
Consider a dipole ($\vec{p}$) in an electric field ($\vec E$) making an angle $\theta$ with the field.
We can see that $V_1-V_2=Ed\cos\theta$
In books, the derivation for the interaction energy of ...
- 436
0
votes
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answers
250
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Potential difference in parallel plate capacitors
I calculated the potential gain/difference for these two cases.
And found that, voltage difference would be higher for the parallel plate capacitor (2nd one). So from my understanding, the capacitor ...
0
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0
answers
48
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Potential energy of a system of three charges question
Two point charges are located on the $x$-axis, $q_{1}=-e$ at $x = 0$ and
$q_{2} = +e$ at $x = a$.
(a) Find the work that must be done by an
external force to bring a third point charge $q_{3} = +e$ ...
0
votes
0
answers
35
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Potential Energy of two charges which are not fixed
Suppose I have 2 charges (+q and +Q) which remain fixed and are placed at a seperation R. They will have some Potential Energy which is kQq/R.
So I wanted to ask that if the charges are not fixed then ...
- 63
0
votes
1
answer
133
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Quantifying potential energy
As per the definition of potential energy we kept a fixed charge, and in the presence of an electric field of the fixed charge, we release another charge of the same sign moving towards the fixed ...
- 529
0
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1
answer
139
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Intuitive explanation that mechanical energy is conserved in gravitational field
Suppose you have $n$ particles with masses $m_1, \cdots, m_n$ with position vectors $\vec{r_1}, \cdots, \vec{r_n}$. Now without any forces except gravity acting on them, conservation of mechanical ...
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