All Questions
Tagged with electromagnetism forces
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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 ...
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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 ...
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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 \...
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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 ...
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What is magnetic shear?
Can someone please summarise to me what exactly magnetic shear is? I know shear as $\tau=F/A$, and intuitively interpret is as, eg, a force on an object and the friction response being shear forces. ...
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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 ...
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Why can we calculate force on a dipole from torque?
In the Feynman lectures he derives the (mechanical) energy of a dipole
$$ U = -\boldsymbol{\mu}\cdot \boldsymbol{B} + \mathrm{constant}$$
by considering only the torque on it in a uniform field. He ...
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Coilgun projectile force calculation
Please excuse me if I am completely wrong because I am a 9th grader but I hopefully am able to explain briefly about my problem. I was trying to create a function to calculate the Force of an iron ...
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Couple acting on quadrupole due to a point charge
I wish to find the couple acting on the quadrupole due to q', assuming r>>a. Here is my working:
Force acting on -2q:
$E_{at \ -2q} = \frac{q'}{4\pi\epsilon r^2} \\
F_1 = (-2q) E = \frac{-2qq'}{...
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Could you calculate the force between two NON-PARALLEL, straight current carrying wires?
Just like there are ways to solve for the force between two straight parallel wires, what is the way we could find the force between non-parallel wires?
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Repulsive force between electrons at relativistic speeds
What happens to the repulsive force between two electrons, once one of the electrons travel at relativistic speeds?
Let's consider two electrons in an atom with magnetic dipole moment, one of which is ...
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Is there a ponderomotive force due to a traveling wave?
Imagine a traveling, EM wave passing through some plasma. The waveform is given by the vector potential:
$A = (0, -\frac{cE_0}{\omega_0}\cos\eta, 0)$
where $\eta = \omega_0t-k_0x$ is the phase. From ...
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Which equation is most valid for finding power dissipation in a induced magnetic pendulum system?
Considering a set up where a conducting pendulum oscillates between two permanent magnets, I want to somehow calculate the power dissipated by the magnetic braking force the magnets provide, in order ...
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What are the conditions according to which the levitation force between a magnet and a superconducting material tends to zero?
According to this article, for a disk-like superconductor and a magnet, if the radius of the superconductor tends to zero or the radius of the magnet tends to infinity, it seems that the levitation ...
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How great is the net force exerted on a superconducting material of a small size being subjected to an external uniform magnetic field?
Assume that we have a very tiny spherical or disk-like superconducting material that is subjected to an externally uniform magnetic field. I want to know if the net force that accelerates the ...
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How can two conductors of unequal lengths exert a force of same magnitude on each other?
I understand Newton's 3rd Law states that if Object (conductor) A exerts a force on Object B, Object A will experience an equal and opposite force. However, in a current carrying conductor Lorentz ...
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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, ...
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A question about Coulomb's law for one moving and one stationary charge
let one charge is moving and another charge is stationary (compulsory). Then the electric force between them can be calculated by coulomb's law?
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Attraction/repulsion forces between two magnets
If I have two identical magnets of equal strengths producing equal repulsive forces between them, and if I replace one of the magnets with a stronger magnet (everything else remaining the same), how ...
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Trying to understand how to apply Maxwell stress tensor to calculate forces
I'm struggling to understand how to use Maxwell's stress tensor to compute electromagnetic forces acting on surfaces. I'll take problem 8.7 from Griffths Introduction to Electrodynamics as an example.
...
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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 ...
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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 \...
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Does the charge distribution of two uniformly charged conducting spheres change as we bring them near each other?
Assume that we have positively charged two solid conducting spheres of the same radius and material. It is evident that the surface charge is uniform on them to eliminate the internal electric field ...
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Does the magnetic field, circulating the moving uniformly charged sphere, exert force/tension on it? If so, how is it interpreted in the charge frame?
I am aware of this SE question, however, it does not solve my problem. Assume that a bulk uniformly charged nonconductive sphere is set in motion along the $x$-axis in the lab frame of reference. ...
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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 ...
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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 ...
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Propulsion of a spacecraft [closed]
If a craft is positioned at the strongest point of the earth's electromagnetic field being either positive or negative and the craft activates the same field it would repel each other would it create ...
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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=...
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Linear Addition of Forces for an Electromagnet design
If I have an electromagnet, designed as below(based off an Inrunner BLDC motor), and want to apply 20N of force to the magnet, would I be correct in saying each protrusion(coil and core pair) only ...
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Are there any relativistic corrections to electrostatic attraction between two charges moving close to the speed of light?
If two opposite charges are moving at a velocity of $0.9c$ relative to a laboratory, but are at rest relative to each other (say the charges are moving in parallel), will there be any relativistic ...
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What is the force between two charges moving at 0.5c relative to each other? [closed]
Suppose two charges, $q_{1}$ and $q_{2}$ are in uniform translational motion relative to each other. If the relativity velocity is relativistic, e.g. $0.5c$, how can the force between the two charges ...
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Torque on a current loop in a magnetic field, could you please explain the derivation and concept?
Torque=mxB
Consider a rectangle loop pqrs of sides l and b , where pq and RS are perpendicular to field , I is the current, B is field , imagine that this loop is placed between 2 magnets.
Force ...
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Where does force act in two parallel current carrying conductors?
F=ILB.so consider length as 5 m and I as 2 ampere and B as 5 T.so the force is 50 N.does this 50 N act at one point or equally applied on full length like pressure.So what does force/length in this ...
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Apparent singularity of Magnetic field generator by a ♾️ conductor [closed]
Let's assume two perpendicular wires: one is infinitely long and the other's length is $l$ (finite).
The second wire is placed vertically on top of the infinitely long wire and there is a distance of ...
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Is the magnetic Lorentz force $\vec{F} = q(\vec{v}\times\vec{B})$ a force of constraint?
I am currently studying the Lagrangian mechanics, and as far as I've understood, forces of constraint are the forces that are perpendicular to the surface of the movement of the object, thus do not ...
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Can the following set up be used to propel something upwards?
Let A and B be solenoids with the same pole facing each other.
Then will their repulsion cause the set up to jump upwards?
Please correct me if I am wrong:
Solenoid A exerts a downward force on ...
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How do you calculate the force between an electromagnet and a piece of iron? [closed]
I am building a simple electromagnet, with an Iron core, and want to calculate the force it can exert on another piece of Iron when in direct contact with it (Basically how much weight it can lift). ...
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Where does the Force on an Electron Come From?
The interaction (of an electron with an external electromagnetic field) is because of the electron's charge, but charge causes an electric field, so, by Syllogism one can say the interaction is ...
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The force experienced on a charge, using macroscopic quantities
Zangwill says (Zangwill, Modern Electrodynamics, 2012 edition, page 40, undersection 2.3.1, "Lorentz Averaging")
...An example is the force on the charge density $\rho$ and current
density $...
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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 ...
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Time lag for generation of electrostatic force
Suppose we make a certain point in space charged. Say we impart some negative charge, such that electrostatic condition is maintained.
Then, after the point gets charged will the electric field due to ...
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Is tension a reaction force or an restoring force?what is tension then?what are the differences in them?
Assume a rope of mass $M$ is connected to a fixed wall and is free from other end
Now,I pull on the end of the rope
My simple questions are:
1.What is the reaction force/Newton's 3rd law pair force ...
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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 ...
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Forces in microscopic scale [duplicate]
When I was thinking about mechanical forces being electromagnetic in nature , This question came to my mind ,
How do we exert such large forces when at the microscopic scale we moved such a small ...
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Poincaré inverse square law unification
A while back, I came across a claim that was something like this: Poincaré said that no two fundamental force laws could have the same mathematical form such as $1/R^2$; that no two fundamental force ...
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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 ...
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Why is electromotive force in magnetohydrodynamics a vector quantity?
In the mean-field dynamo theory in magnetohydrodynamics, I frequently came across a quantity;
$\langle v'\times B' \rangle$, which is termed as the mean electromotive force. I want to know that why is ...
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Enhanced capacitance by magnetism?
Consider the first picture.
This is much like a parallel plate capacitor charged by a battery. But instead of parallel plates we are using parallel rings. The rings are attracting each other because ...
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Lorentz Force and current carrying wire in an homogeneous magnetic field
Consider the following situation.
There is a metallic strip situated in an homogeneous electric field. The lines of the electric field go from left to right, so the free electron in the metallic ...
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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 ...
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