All Questions
Tagged with electromagnetism potential-energy
130
questions
35
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Why don't we define potential due to a magnetic field?
We define electric potential and gravitational potential and use them quite often to solve problems and explain stuff. But I have never encountered magnetic potential, neither during my study (I am a ...
user243267
31
votes
10
answers
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How is energy "stored in an electric field"?
My physics teacher told me the statement "The energy of a capacitor is stored in its electric field".
Now this confuses me a bit. I understand the energy of a capacitor as a result of the ...
- 492
31
votes
8
answers
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What is potential energy truly?
I have a problematic question for which I have been unable to attain a satisfactory answer. What is potential energy truly?
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I have read about how potential energy can be seen as the "highering" ...
- 881
21
votes
5
answers
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Why should Conservative forces have their curl equal to zero? (intuition)
There are several conditions that must be met in order for a force to be conservative.
One of them is that the curl of that force must be equal to zero?
What is the physical intuition behind this?
If ...
- 7,720
15
votes
2
answers
5k
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How is energy stored in magnetic and electric fields?
We say that there is energy associated with electric and magnetic fields. For example, in the case of an inductor, we give a vague answer saying that an energy of $\frac{1}{2} LI^2$ is stored in the ...
- 7,203
10
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1
answer
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Is there any potential associated with magnetism?
Can anybody please tell me if magnetism is a conservative force or if there is a field associated with it? How to reason? One thing I know is that the work done by a magnetic force is equal to $0$.
- 103
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3
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If magnetic force can't do any work, then how can we define a potential?
I am confused about the idea that magnetic forces do no work. If something has a potential, then it has energy and hence can do work. I am using the logic of electric fields for this reasoning. I have ...
- 137
8
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3
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Coincidence, purposeful definition, or something else in formulas for energy
In the small amount of physics that I have learned thus far, there seems to be a (possibly superficial pattern) that I have been wondering about.
The formula for the kinetic energy of a moving ...
7
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5
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Direction of rotation of proton in magnetic field--opposite to a dipole
Chatroom created by @pcr for discussing this: http://chat.stackexchange.com/rooms/2824/direction-of-rotation-of-proton-in-magnetic-field
Here's a small paradoxical question I was asked a long time ...
- 19k
6
votes
5
answers
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Do magnets have infinite potential energy?
Pardon me if my question sounds "out there", I've been out of touch with recent developments in physics, but this is something I've never really put deep thought into.
I know that when two ...
- 1,043
6
votes
1
answer
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Does this example contradict Earnshaw's theorem in one dimension?
This is basically a continuation of the post here.
Consider electrostatics in $1$-dimension (say, the $x$-axis). Now consider a positive charge $+q$ located at $x=0$, and two equal negative charges $...
- 26.8k
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What is the correct expression for the magnetic energy density inside matter?
I'll use a magnetized sphere as an example, of radius $R$, with a magnetization density $\vec{M}$. The magnetic moment of the sphere is $\vec{\mu} = \vec{M} \, V$. The magnetic field inside and ...
- 7,592
5
votes
4
answers
985
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Deeper Meaning to the Nature of Lagrangian
Is there a more fundamental reason for the Classical Lagrangian to be $T-V$ and Electromagnetic Lagrangian to be $T-V+ qA.v$ or is it simply because we can derive Newton's Second Law and Lorentz Force ...
- 177
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2
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Deriving the Lorentz force from velocity dependent potential
We can achieve a simplified version of the Lorentz force by
$$F=q\bigg[-\nabla(\phi-\mathbf{A}\cdot\mathbf{v})-\frac{d\mathbf{A}}{dt}\bigg],$$
where $\mathbf{A}$ is the magnetic vector potential and ...
- 539
5
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1
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Can someone explain how magnetic potential energy can exist even though the field is non-conservative?
$U=-B\cdot \mu$ is defined to be the magnetic potential energy, I saw this in my lecture notes, but we had already talked about the fact that since the work done to move a charge there is path ...
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