All Questions
144
questions
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46
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What happens when both magnetic field and electric field is applied to a charged particle?
Now what exactly happens when magnetic field and electric field is applied perpendicularly? What happens when they are not perpendicular?
In the question, it says that a magnetic field and electric ...
- 83
14
votes
7
answers
4k
views
Why does a charge need to have a velocity to experience force in a magnetic field?
While studying magnetism, I learned that force on a charged particle inside a magnetic field is
$$\mathbf{F}=q(\mathbf{v}\times\mathbf{B})$$
where all symbols have their usual meaning, which implies ...
- 161
0
votes
0
answers
15
views
What is the physical meaning of the torque term involving the magnetic displacement force?
In Zangwill's Modern Electrodynamics the magnetic torque is derived in Eq. 12.63 to be
\begin{equation}
\mathbf{N}(\mathbf{r}_0) = \mathbf{m} \times \mathbf{B}(\mathbf{r}_0) + \mathbf{r}_0 \times \...
0
votes
0
answers
28
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Force on an iron ball in a homogeneous magnetic field [duplicate]
Just a simple question. If I have a homogeneous magnetic field and I put an iron ball into this field, it would be attracted to the source of the magnetic field. But how do I calculate the force that ...
- 89
1
vote
2
answers
35
views
Force between two current carrying conductors
lets say I have two wires. each has a magnetic field due to its current. this magnetic field is present in the other wire causing a force in that other wire. Now I understand that changing the current ...
- 117
0
votes
0
answers
21
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Maximum force of a metal ball going trough coil
I've been trying to figure out the maximum force of a metal ball going trough a coil.
I have:
$$ m=\chi_m V B \qquad B=N \mu_0 I R^2 \frac{1}{2(x^2+R^2)^{3/2}} $$
Also that $F=(m\cdot B)'$. However, ...
- 103
1
vote
1
answer
35
views
Getting the force somehow using magneticfield force (tesla)
First off, sorry if not everything makes sense, english isn't my first language so some scientific terms may sound weird if they're in English. For a project we are making a coil gun. So we get a ...
- 11
0
votes
1
answer
78
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The magnetic force is conservative when the magnetic field is static, what is its potential function then?
The magnetic force $\vec{F}$ can be conservative when the magnetic field is a static. That is $\vec{\nabla} \times \vec{F}=0$, so it follows that there is a scalar function $f$ such that $\vec{F}=q \...
- 959
1
vote
2
answers
120
views
How can two observers agree on the force between 2 moving charges?
I'm having a hard time figuring this out. This question has been asked before, I saw the answers, but I'm still struggling with this. So I decided to ask.
I want to calculate the same force for both ...
- 11
3
votes
4
answers
87
views
Is the Lorentz force applied to bulk objects?
Assume that a bulk uniformly charged ($+Q$) nonconductive sphere is set in motion inside a uniform magnetic field. Is it correct to claim that the trajectory of the bulk sphere inside the magnetic ...
- 2,503
1
vote
4
answers
197
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What's the difference between $f= i (l × B)$ and $f= (i∫dl )× B$?
for any current carrying conductor of any arbitrary shape in uniform magnetic field experiences a force given by F = i (l × B) where l is length between end and start points of the conductor and in f=...
- 33
1
vote
1
answer
132
views
Ratio between electric and magnetic forces
Suppose I have two beams of electrons moving at speed $v$ separated by a distance $d$. I can work out magnetic and electric forces between them...
For the magnetic force, we treat the two beams wires ...
- 2,446
2
votes
1
answer
287
views
Can a current carrying loop experience force due to its own magnetic field?
In my opinion, the wire must expand due to the magnetic force acting radially outwards on two diametrically opposite ends of the loop as a result of the equation:
F = I(dl × B)
Where B is the ...
-1
votes
2
answers
260
views
U-shaped magnet and the moving charge: Where is the origin of the Lorentz force from the viewpoint of the moving charge?
Assume that a charge $+q$ is located at rest between the poles of an infinitely long U-shaped magnet, which is laid along the $x$-axis. If the charge slowly accelerates to a velocity $v$ along $x$ and ...
- 2,503
0
votes
0
answers
48
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If magnetic force is perpendicular to the direction of motion, does that mean the direction of motion prior to the magnetic force doing anything?
I want to make sure I'm understanding this correctly:
My understanding is that magnetic force can do no work because it can never change the speed of an object -- instead it can only cause ...
- 2,327