All Questions
28
questions
0
votes
1
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124
views
Violation of energy conservation due to Lorentz Force?
We know that work done by Lorentz Force $q(\vec{v}\times\vec{B})$ is $0$ on moving charge in magnetic field as velocity is always perpendicular to the force. This means that kinetic energy remains ...
- 1,168
0
votes
0
answers
13
views
Potential inside a Charged Conductor near another Charge
Let's say that we have a solid conducting sphere with radius r and this conductor is given a positive charge of q1. We know that the charge will get distributed on the surface to reduce field inside ...
0
votes
1
answer
107
views
When finding electric potential and electric potential energy is it all adding the total?
I am not sure what the difference is between the two. For example, when I add the total of all the potential for every point charge isn t that finding the potential energy since you also add all the ...
user361546
0
votes
1
answer
97
views
Lorentz force from potential- extra term?
I'm trying to verify the E.M potential energy $U= \int{A_\mu J^\mu} = q(\phi - A_j v^j )$ by using the connection:
$$
F= - \frac{\partial U}{\partial r} + \frac{d}{dt} \frac{\partial U}{\partial v}
$$...
- 2,141
0
votes
1
answer
155
views
Does electric current flow from higher potential to lower potential or from higher potential energy to lower potential energy?
Here, $O$ is a field charge with a $+T$ charge. $A$ and $B$ are test charges with $+T_1$ and $+T_2$ charge, and they are fixed in place. Suppose the points at which $A$ and $B$ are situated are $P_1$ ...
- 1,018
0
votes
2
answers
215
views
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
0
votes
3
answers
547
views
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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votes
1
answer
53
views
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
1
vote
2
answers
105
views
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
0
votes
1
answer
64
views
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
-2
votes
1
answer
50
views
Expressing $E$ field and $B$ field using potentials
Why dont we have a term that corresponds to the change in E field in eq1.61b like we have in eq 1.61a?
0
votes
1
answer
162
views
Difference between potential and potential energy in physics?
Title says it all.
What exactly is the difference between potential and potential energy in conservative force field like gravity or electric force field. I am getting confused between the two ...
- 2,042
35
votes
5
answers
6k
views
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
1
vote
1
answer
456
views
Potential Drop across Inductor VS Potential drop across Rotating coils in $B$-Field
I was trying to understand the difference between the Back emf generated across Inductor due to change in current and Back Emf Generated across a coil that is rotating in presence of B Field.
...
- 273
6
votes
1
answer
480
views
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