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.

3,116 questions
Filter by
Sorted by
Tagged with
1 vote
39 views

1 vote
71 views

Electric potential energy, Electric potential and self-energy of a body

The total work done to bring all the charges constituting a body from infinity to the body one by one is called the electrostatic potential energy of the body. And if I divide the expression of ...
45 views

Gravitational potential due to arbitrary shape

Outside the uniform sphere, the potential is expressed as if all the masses are concentrated in the center of the sphere. Is it also true for arbitrary shape? That is, outside any body, is potential ...
1k views

Can a positive charge have a negative potential?

I'm studying about electrostatic potential due to a point charge and was wondering - can a positively charged point have negative electrostatic potential? V=Kq/r for a positive point charge. Assume B ...
• 113
30 views

Electrostatic potential expression

In my lecture(not regarding electrostatic, it was just for an example), the professor had made the statement below: I think he is denoting V as 'electrostatic potential energy' and $\phi$ as '...
• 27
36 views

What does 0 volts mean for a Van de Graaf generator?

I am trying to understand how two different definitions of zero-voltage reconcile in the experimental setup of a Van de Graaf generator, or at least how I understand that it is being described. ...
• 1,538
51 views

Uniqueness Theorem and boundaries conditions

I was recently studying Jackson Electrodynamics and faced some issues directly. I have studied Griffiths Electrodynamics and I knew about the uniqueness Theorem from it. But in Jackson, they proved it ...
1 vote
33 views

Does it make a difference whether potential difference is denoted as a negative or positive value in an answer, since it's just a scalar? [duplicate]

Does it make a difference whether potential difference is denoted as a negative or positive value in an answer, since it's just a scalar? Sorry if it's a dumb question, I was just a little unsure.
• 11
28 views

Apparent contradiction while calculating potential inside shell due to off center charge

Consider the following scenerio$-$ A point charge $Q$ is placed at an off center point $B$ in a spherical shell made out of a conducting material. We are required to find the potential at the center. ...
• 408
38 views

Reflection of quantum particle colliding with a potential barrier

Let a quantum particle be subject to a one dimensional step potential barrier $V$ such that: $$V(x)=\begin{cases}0, \ x<0 \\ V_0, \ x>0\end{cases}$$ where the particle's energy is $E>V_0>0$...
• 1,245
173 views

Where does the four-vector potential $A^\mu$ originate?

Now the default answer to this may be, "It has no origin because it's a definition", but let me just try to justify my concern here. On page 842, equation (22.91) of "Modern ...
• 295
44 views

How do we write the potential difference between the final and initial points?

If you want to find the potential difference between point A and point B, the potential difference is written: $$V_{ab}= V_{a} - V_{b}$$ or $$V_{ab}= V_{b} - V_{a}$$ AND is work the same thing? I ...
• 103
1 vote
80 views

When should we use $\sigma/\epsilon$ and $\sigma/2\epsilon$? [closed]

I was doing a question, in this i have to find distance between proton and plate.. so i use work energy theorm ie change in ke is net work done.. so as for electric field i use gauss law and taken ...
• 21
53 views

Confusion about reference point for potential difference

My confusion comes from trying to find the potential difference of a spherical conductor with an inner shell of radius $R_1$ and an outer radius $R_2$. I tried using a reference point of $R_1$ and ...
93 views

Insertion of dielectric inside capacitor when capacitor is connected to a battery

When a capacitor is connected to an external voltage and a dielectric is inserted slowly across the plates, the energy of the capacitor increases. The energy preciously is $CV^2/2$ and after the ...
13 views

Potential of a conductor when the charge distribution is uneven due to induction

If a negatively charged object is brought near a neutral conductor, there would be an excess of positive charges on the side of the conductor near the charged object, while there would be an excess of ...
• 37
1 vote
30 views

Charge transferred from Sphere and Disc after being brought into contact

Recently I came upon the following question $-$ A conducting sphere of radius $R = 1 m$ is charged to a potential $V = 1000$ volts. A thin metal disc of radius $r = 1 cm$ mounted on an insulating ...
• 408
76 views

Mirror image Electric field and potential

pg My book says the electric field due to a positive point charge at a certain distance from the surface of flat, infinite earthed conductor can be obtained by introducing a virtual negative mirror ...
1 vote
104 views

Electric Potential in circuit confusion

I reviewed some of the fundamental physics and I looked back at the equation for Electric potential at a point p: $$V(p) = k \sum_{i} {\frac {q_i} {r_i}}$$ where p is the point at which the potential ...
• 135
48 views

Equipotential surfaces

Why two equipotential surfaces cannot intersect What is the logic and reason behind it?I know that two electric field lines cannot intersect but what about equipotential surfaces?
1 vote
38 views

Electrostatics: Electric Potential of Earth [duplicate]

I have a very basic question which is: Why we consider the potential of Earth to be zero? Generally in physics we consider the electric potential at infinity to be zero. But while reading about ...
• 64
1 vote
74 views

What does this formula of Electric potential generated by spherical symmetric charge density mean?

I found this formula (14.5) in the book Classical Electromagnetism in a Nutshell by Anupam Garg, $$\phi(r) = \frac{1}{r} \int_0^r 4\pi r^2\rho(r)\;dr+\int_r^{\infty}4 \pi r\rho(r)\;dr.$$ I know it's ...
1 vote
108 views

Derivation and theory for $I = kV^n$ [closed]

I performed an experiment in college to study the nature of a filament of a lamp, determine $k$ and $n$ in the relation mentioned, and study the variation of wattage of a lamp. I assume ohm's law is ...
• 25
21 views

Potential difference between two non-grounded equipotential plate

I am attempting to solve for the potential difference between two non-grounded equipotential plates using Poisson's PDE. The relevant Maxwell equation considered is $∇⋅E=\rho$, where $E$ represents ...
• 1
43 views

Equation of a equipotential surface

I have been trying to find a equation for the equipotential surface of a dipole , so I started with a simpler system of a singular charged particle , here are few things I know about the equipotential ...
18 views

How to transform the volume integral of a curl of the product of a potential with a magnetic field into a surface integral?

Problem 6.5 of Jackson electrodynamics says: A localized electric charge distribution produces an electrostatic field, $\vec{E} = - \vec{\nabla}\Phi$. Into this field is placed a small localized time-...
151 views

Why does the capacitance of a capacitor depend on charge and potential?

The formula of capacitance is $$C = \frac{Q}{V}.$$ So the capacitance of a capacitor should depend on the charge and potential but it doesn't. Why?
21 views

Will the potential on surface of a irregular conducting sphere surface be constant?

We know that potential on surface due to a regular conducting sphere is constant. But what will it be when the surface is irregular and charge distribution is non-uniform?
96 views

What are exactly the loop correction to the potential? [duplicate]

I am struggling with the concept of quantum effective action, but first recall the definition : given a Wilsonian effective action $W[J]$ of our theory, the quantum effective action is just \Gamma[\...
• 439
44 views

I'm trying to figure out how to go from the electric potential of a uniformly charged semi-circle, to the electric field

The question asks "A thin plastic semi ring of radius $R$ has a uniform linear positive charge density $\lambda$. a) Determine the electric potential $V$ at point O, the center of the semi ring. ...
• 21
1 vote