# 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.

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### Why can't we ascribe a (possibly velocity dependent) potential to a dissipative force?

Sorry if this is a silly question but I cant get my head around it.
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### Hamiltonian for a system of 3 interacting particles and the meaning of potential

I'd like to discuss some physics basic. assume we have 3 particles $\{\vec{q_i},\vec{p_i}\}, \quad i=1,2,3$ whereas $\vec{q_i}$ is the position and $\vec{p_i}$ is the momentum. We also have a "pair-...
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### The Schrodinger equation with strange potential

The particle of mass $m$ moves in potential $$V(x) = \dfrac{\alpha \left( \left( 2 \alpha +1 \right)x^2-a^2 \right)}{m \left( a^2 + x^2\right)^2},$$ and $\alpha > 1/4$. Find the energy and the ...
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### Can we speak of an absolute voltage without a convention?

In most practical cases I have seen, voltage was regarded as a difference in electric potential, save the odd change of magnetic flux over time which, as a form of change, also conveys the notion of a ...
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### Terminal potential difference of cell [closed]

I was given two cell X and Y of emfs 6V and 4V and internal resistance 2ohm and 8 ohm respectively connected in series with an external resistor of resistance 10 ohm and asked to find terminal ...
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### Potential inside a hollow sphere (spherical shell) given potential at surface

Suppose that we have a hollow sphere (spherical shell) whose surface is held at some constant potential V0. What is the potential inside the sphere? I had an argument with my physics professor over ...
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### Energy spectrum for a step potential

Most of the books tend to give this explanation that for a bound physical system, the energy and momentum eigen values have discrete spectrum and otherwise, they have a continuous spectrum, which I ...
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### 1D Finite potential well: solutions with $\sinh$ and $\cosh$?

So I am studying the (one dimensional) quantum mechanical finite potential well defined by: $$V(x) = \cases{0, &|x|>a\cr -V_0, &|x|<a}$$ where $V_0>0$ is a real number. I know ...
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### Why is the electric potential at infinity zero?

As per net results, the potential at infinity is considered to be zero. Apart from considering this as a physics law, is there any proper reason why we consider potential at infinity to be zero?
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### If the potential shifts by $a$ in x axis, would the Wave function shift by $a$ as well?

While solving problems in QM I had the following question in mind. If the solution is found to be $\psi(x)$ for the original potential $V(x)$ in the time independent Scrödinger equation, would it be ...
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### Constant current through a conductor is a problem of electrostatics or electrodynamics?

When you connect a constant voltage source across a resistor, there will be a constant current through the wires. Is this a problem of electrostatics or electrodynamics? If it is a problem of ...
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### Why is $\nabla U(r) = \frac{dU(r)}{dr} \nabla r$?

Does anyone have a proof for the equation: $$\nabla U(r) = \frac{dU(r)}{dr} \nabla r$$ Where $r=|{\bf r}|$ is the distance and $U(r)$ is a potential for a central force. This is from page 13 of "...
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### What would the graph look like if the electrodes were non-equidistant from the dipole?

Hypothetically speaking using the diagram above. If the negative electrode was very far away from this excitable tissue and the positive electrode was right next to it. What would the voltage graph ...
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### Non-symmetric double-well energy levels

While going through Konishi's and Paffuti's book Quantum Mechanics: A New Introduction, I came upon an example that I see in many books on QM - the double well potential. The problem is then posed as ...
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### Meaning of the differential form of Gauss's theorem and Poisson's equation

The differential form of Gauss's theorem is that the divergence of the electric field is proportional to the charge density of the region being considered (crudely speaking). My question is, how is ...
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### Electric potentials and superposition

I had a question regarding the addition of electric potentials. Consider two positively charged particles $q_1$ and $q_2$ at distance $R$ apart. Let the charges have magnitudes $q_1$ and $q_2$. For a ...
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### Why is $\varepsilon=\frac{W_{chemical}}{q}=\Delta V_{-\to+}$ the emf of a battery?

In my book, the electromotive force (emf) of a battery is defined as follows $\varepsilon: = \frac{W_{chemical}}{q}$. The book then states that for an ideal battery, $\varepsilon = \Delta V_{-\to+}$, ...
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### What is the difference between positive negative potential and positive, negative work done?

if work is done along the direction of force,then the work is regarded as positive work and if work is done in a direction opposite to the direction of force then it's regarded as negative work....
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### Lagrangian of a particle in a gravitational potential and conservation of angular momentum

I'm trying to prove via Noether's Theorem that the angular momentum of a massive particle in a gravitational field is conserved. The attempt follows: OBS: I'm working in the euclidean space so I'll ...