All Questions
Tagged with electromagnetism potential-energy
130
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170
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Why is the force that does the work, when calculating the electric potential energy, symmetric to the electric force? [closed]
"The electrical potential at a point is the work per unit charge required to move the charge to that point (r) from another point which has been assigned a potential of zero ($r_{0}$)". This ...
- 169
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2
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215
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If Electric potential energy is not zero at infinity, nor at any finite value, when it is?
The electric force decreases with the distance ($1/r^2$). If that's so, if we don't define zero to be in any finite distance value, nor at the infinity, there's just no zero reference at all for the ...
- 169
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3
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547
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What Griffiths meant by "the potential is not unique"?
The potential is not unique—any constant can be added to $V$ with impunity, since this will not affect its gradient.
The vector potential is not unique—the gradient of any scalar function can be ...
- 91
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4
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517
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Can non-conservative fields store potential energy?
I was taught that a time-varying magnetic field generates an electric field which is non-conservative in nature, and my teacher also told me that when a conducting coil is placed in a region with a ...
- 8,230
2
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1
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83
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How do I find the potential energy lost by a ball bearing moving away from a magnet?
I am carrying out a physics project over the next few weeks and am looking at the Gaussian gun. I'm sure most are familiar with it, but if not it is the experiment where you roll a ball bearing into ...
- 21
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44
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What's the potential energy in a system of magnets?
I am trying to model a 3d pendulum consisting of a magnetic bob attached to a string. If the pendulum is allowed to swing over a structure of permanent magnets, it will display complex motion (here a ...
- 91
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53
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Why is the work through the element the same as the potential difference if we define potential difference this way?(lumped elements)
In the Feynman Lectures on Physics part ||, chapter 22-3 he defines potential differnce like this:
The picture is an element in a curicuit, the black lines on top and the bottom are the conductors, ...
- 199
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2
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105
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Why is the sense of the electric field the one that goes from the highest to the lowest values of an electric potential?
To clarify, what's the reason behind it and why is it not the opposite?
- 13
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1
answer
409
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What is doing the work on a magnetic dipole in a magnetic field?
I understand that the torque acting on a magnetic dipole in a magnetic field is given by $$\vec\tau=\vec\mu\times\vec B \therefore \tau = \mu B sin\phi$$ It follows that the work done as the dipole ...
- 155
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28
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Different forms for the formula of Electrostatic Energy for a two body system
I found this formula for total electric energy stored in a two body system in I.E. Irodov as
$$W= W_1 + W_2 + W_{12}\tag1$$
where $W_1$ and $W_2$ are self energies of the bodies and $W_{12}$ is the ...
- 1,568
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436
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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
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2
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195
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Is electric potential energy responsible for energy release in nuclear fission and nuclear potential energy in fusion? What if elec. force not exist?
It was my doubt and I thought it may be electric potential energy which is responsible for energy release in nuclear fission and by bombarding neutron we only provide energy to nucleons to cross ...
- 15
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1
answer
64
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Why is the distance where electric field is zero different from the one where potential is zero?
I came across this exercise which says that in an xy plane there are two charges: q1 = q and q1 = -12q, and that q1 is at (0,0) on the plane and q2 at (0,9). I was asked to find the abscissa , which ...
- 13
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1
answer
463
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Validity of $E$ field energy density equation
As far as I'm aware, the most popular/rigorous way of deriving $E$ field energy density is starting with the potential energy of a continuous charge distribution (which itself has some flaws that I ...
- 6,636
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3
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4k
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Lagrangian in presence of an Electromagnetic Field
Given the following definition of the Magnetic Vector Potential $\vec{A}$:
$$\vec{A} \ \mid \ \vec{B}=\vec{\nabla}\times\vec{A}$$
We can derive (but I don't know how) that the Lagrangian in presence ...
- 4,577