Questions tagged [potential]
Scalar and vector potentials in electromagnetism. The scalar potential is potential energy per unit charge. For potential energy, use the [potential-energy] tag.
3,266 questions
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Structure of Higgs potential
The Higgs potential is written as $V(\phi) = -\mu^2 |\phi|^2 + \lambda^2 |\phi|^4$, where $|\phi|^2 = \phi^\dagger \phi $ and $ \phi $ is a complex scalar doublet. My question is: why do we not ...
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1 answer
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About the vector potential
I have a question that is probably trivial concerning the vector potential used in electromagnetism. When solving the wave equations for the vector potential $\mathbf{A}$, we are essentially ...
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What is the equation for the change in electric potential due to a field generated by a point charge? [duplicate]
I'm a current AP Physics 2 high school student with a test in a few days; a swift reply would be very much appreciated. Thank you in advance. My question is concerning the formula for the change in ...
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1 vote
2 answers
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Why does the Poisson equation help to compute the electric field $E$ when the integral is intractable?
Currently I am reading through Griffiths Introduction to Electrodynamics and I am in chapter 3.1 about Laplace's equation. The author explains that our aim is to compute the electric field given a ...
-1 votes
2 answers
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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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3 answers
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When do we consider that grounding the conductor makes the potential zero?
When do we consider that grounding the conductor makes the potential zero? I was recently seeing why is the outer charge of the system of grounded conducting plate becomes zero, and the reason given ...
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-1 votes
1 answer
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Question about Schrödinger equation with scalar and vector potentials from Sakurai
This is from page 127 of Sakurai QM: How did they obtain this result? I understand the factor comes from the Hamilton on the LHS, but how were they able to pull out the factor out of the bra-ket like ...
1 vote
1 answer
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Potential energy gradient of two masses
Say there are two masses , each of mass m; moving along the x axis under the influence of mutual gravitational force. No other external forces are there on them and hence center of mass does not ...
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1 answer
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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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Why is the Electric Potential Between Two Oppositely Charged Points Zero? [closed]
Assuming two charges of +5C and -5C are placed at points A and B respectively, why is the potential between them zero if the electric field between them is constant and non-zero? It makes sense if you ...
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How to obtain $ϕ(a)$ to solve a multi-scale matter density contrast equation in cosmological perturbation theory?
I have derived the equation for the evolution of the matter density contrast $\delta_M(a)$: $$ \delta_M''(a) + \left(\frac{4}{a} + \frac{H'(a)}{H(a)}\right)\delta_M'(a) + \frac{3 \phi'(a)}{a} - \frac{...
5 votes
1 answer
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Why's the Electric Field intensity within a hollow sphere zero?
I have read in my physics book that in the case of a conductive hollow sphere, containing an amount of charge on its surface, the electric field intensity inside it will be zero, and as a result, the ...
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1 vote
1 answer
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Connection between magnetic field $\bf B$ and vector potential $\bf A$ in Griffiths
In Griffiths' Electrodynamics (3rd Ed.) p. 240 there is a triangle of relations between $\bf{A}, B$ and $\bf J$ with an indication of the vector operations that link these quantities in both ...
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Comparison of Equation 6.10 and 5.85 in *Introduction to Electrodynamics* (4th edition) by Griffiths
I am confused about equation 6.10 in Introduction to Electrodynamics (4th edition) by Griffiths. Using $\mathbf{R} \equiv \mathbf{r}-\mathbf{r}'$ (instead of his script $r$), equation 6.10 describing ...
3 votes
2 answers
179 views
Non-existence of bound states for $V(x)=-\alpha/x^2$ in 1D [closed]
I am trying to determine whether a potential of the form $$ V(x) = -\frac{\alpha}{x^2} $$ admits bound states in 1D quantum mechanics. My guess is that it does not: by dimensional analysis I cannot ...
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