For questions that utilize the concept of magnetic fields (commonly denoted by the letter B), or for questions whose answers likely involve magnetic fields. More specific than the [tag:magnetism], as questions about the phenomenon & theory of magnetism do not necessarily involve the discussion of ...

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Wire with current in magnetic field $\vec{B}$has force $\vec{F_1}$. When rotated, $\vec{F_2}$. Find $B$

I have the following question: In a wire with $10cm$ there is a current $4A$ going 'upwards' in the $z$ axis. The force over this field, under a constant magnetic field $\vec{B}$ is $F = -0.2\vec{i} ...
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15 views

How to calculate maximum magnetic flux density of magnet?

I have some magnets of which I need to calculate the maximum magnetic flux density B. I don't have any dedicated setup to measure the value. Is there any way in which I can measure it by relating it ...
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1answer
14 views

Which way is the magnetic field headed? [on hold]

Question Is the magnetic field directed into the page or out of the page? I am using this right hand rule --> RHR So anyhow, my index finger is pointing downwards, and since the magnetic force is ...
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13 views

Magnetic dipole moment aligning with external field [on hold]

Is there a law governing the tendency for the magnetic dipole moment to align with an external magnetic field? If you look at the classical model of an electron orbiting a nucleus, Fleming's Left Hand ...
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15 views

Could dark energy and particles create magnetic field? [on hold]

Could dark energy create magnetic fields or is this just quintessence theory?
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17 views

How Do I find the Thermal increase of a ideal gas flowing through a magnetic field? [on hold]

I am thinking of turning dissociated 2H_2 and O_2 into plasma by forcing it through a electromagnet field. what are the equations to determine the thermal energy added to the gas. I'm thinking to ...
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3answers
50 views

Right Hand Rule on the magnetic field not working? [on hold]

Background: The magnetic field is going into the page and the velocity of the particle is going towards the right. What is the sign of the particle? I keep getting this wrong. The magnetic field ...
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1answer
57 views

Motion of an electron in a magnetic and electric field [on hold]

I have this problem where i should find the direction and magnitude of the electric and the magnetic force on the electron. E = 1000 N/C B = 2,5 T v = 500 m/s ...
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36 views

Lab experiment: hysteresis disappears, reappears and then disappears again. How?

In my college laboratory we were assigned an experiment to measure the hysteresis curves of a certain ferromagnetic material at different temperatures. Sounds simple, right? Well, the block of Monel ...
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1answer
29 views

Does the electrons in Stern-Gerlach aplliance change their energies and how?

When an electron goes thru a Stern-Gerlach appliance it changes its spin projection. Then there must be a change of energy content of the electron due to this event. But it is also known that magnetic ...
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1answer
45 views

Why is it possible to produce electromagnetic waves using a charge and electric or magnetic field? [on hold]

Why electromagnetic waves can be produced by the motion of charge in electric or magnetic field? Explain.
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1answer
19 views

How to find the force of a magnetic field, resolving the components?

So, in answering this question the book resolves the components of the Force vector in this manner; $\mathrm dF_x= \mathrm dF \sin \theta$ $\mathrm dF_y= \mathrm dF \cos \theta$. And then, ...
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1answer
22 views

Approximating magnetic field at center of current loop by solenoid of 1 turn

It's well known that by application of biot-savart law, the magnetic field at the center of a loop of current is $\frac{\mu_0 I}{2r}$. Now when we consider a solenoid, isn't the resulting magnetic ...
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41 views

Dark energy and magnetic field [on hold]

I have learned that a photon creates it's own magnetic field. Arno Penzias & Robert Wilson discovered the background radiation from the Big Bang. Could this also be the time of the creation of ...
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0answers
29 views

Lorentz sphere correction

I am studying Lorentz surface correction for magnetic fields. I know that if we consider a uniform distribution of magnetization, the field can be computed as three contribution: $H+H'+H''$ where $H$ ...
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3answers
28 views

Ampere's law for a rectangular plate?

If a conductive wire was carrying current $I$, it would create a magnetic field: $$B=\frac{\mu_0I}{2\pi r}$$ However, if it's not a wire, but instead a plate how would the expression change/adjust ...
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0answers
16 views

Current density to find the magnetic field and Lorentz force?

Problems where there is a copper wire of a large diameter, the solution would tend to use current density $J$ to accurately compute the magnetic field $B$ at a distance. Why so? Why not simply use ...
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1answer
30 views

Ampere's law and Stokes' Theorem for current density

In both Griffiths and Jackson, Ampere's Law (or conversely the curl of the magnetic field) is derived by applying Stokes' Theorem to the surface integral of the current density J. The argument relies ...
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+200

Can you deduce absolute motion through magnetism?

Trying to understand magnetism I stumble into this example: Suppose there are two electrons travelling side by side in deep space (say, between Mars and Jupiter) at 1 cm distance at .99 c. In this ...
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1answer
38 views

electron in magnetic and electric field

I have this problem where i should find the direction and magnitude of the electric and the magnetic force on the electron. And then I'm supposed to find the direction and magnitude of the ...
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0answers
34 views

What does a particle's path look like in a region with both magnetic and electric fields that are perpendicular? [closed]

Given a uniform electrical field E and a uniform magnetic field B that is perpendicular to it, and a charged particle q that is moving in that field, how does the particle's path look like? How do I ...
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1answer
27 views

Solenoid vs coil of wire

This may sound pretty basic, but: I'm studying for my AP Physics exam, and I am confused. Apparently, the formula for the magnetic field in the center of a loop of wire with $n$ turns is: ...
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0answers
27 views

what happens to light when it passes through a magnetic field of infinite feild strength? [closed]

Light has both particle and wave nature.If light is to be considered as a particle what happens to light when it is passed through a media of infinite magnetic intensity and infinite field ...
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0answers
15 views

Would colliding Magnetars create Gravito-Magnetic waves? [closed]

Using similar physics involved in creating the gravitational waves, would a similar thing happen but create Gravito-magnetic waves with magnetars colliding? What effect would this wave have on ...
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0answers
16 views

Magnetic force on an iron nail

Work done by a magnetic force is zero but the why iron nails are attracted towards a magnet. The fly towards a magnet so the gain K>E i.e work has been done on them. I know its not actually the ...
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0answers
13 views

Can a diamagnetic levitator levitate non-permanent ferromagnetic materials?

I am building a diamagnetic levitator that will eventually levitate a small neodymium cube. However, is it also possible for an iron cube to be levitated as well? I know that diamagnetic materials ...
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1answer
30 views

Is it possible to levitate large objects through diamagnetic levitation?

I am currently building a diamagnetic levitator with a strong neodymium magnet, two slabs of bismuth (a diamagnetic material), and a small neodymium cube to levitate. However, I was wondering if it ...
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2answers
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how do we actually count the number of magnetic field lines and what does the gap between those lines describe?

on the internet,(http://nuclearpowertraining.tpub.com/h1011v1/css/h1011v1_53.htm), there is a statment which says that 1 Wb is $1\times 10^{8}$ magnetic field lines. My question is, How do we count ...
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1answer
49 views

Questions about Magnetic field [duplicate]

I have two questions about Magnetic Field. Given a particle with mass m, charge q and uniform B field. B is going into the page, and particle is moving to the right Like this. The textbook says ...
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1answer
92 views

High Level Understanding Q: What *is* a magnetic/electric field?

Note: I have seen this question -> (What is a magnetic field) and would still like some clarification. I have also seen https://www.youtube.com/watch?v=hFAOXdXZ5TM and ...
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0answers
21 views

Explanation of absorption from Bloch Equation

Suppose in a magnetic resonance experiment the microwave/rf field is applied in x-direction.How to say that the component of magnetization which is out of phase with the microwave magnetic field leads ...
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0answers
13 views

How to calculate pull force of a solenoid with permanent magnet plunger (NdFeB)?

The solenoid is air core. If we use permanent magnet like NdFeB as a plunger, how to calculate the pull/push force of the solenoid with plunger?
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0answers
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Why does a 2-sided propagating EM wave become 1-sided if B is made proportional to E?

If you simulate the propagation of an electromagnetic wave in 1D free space (no charges or currents) with initial conditions of $E\neq0$ and $B=0$, and you look at a movie of $E$ vs time, then after ...
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0answers
17 views

use FEMM to simulate electric field for a magnet inside a coil

I'm trying to simulate a magnet inside of a coil of wire, with and without current running through the wire. I'm using the free FEMM software to try to simulate this, but I don't think i'm setting ...
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0answers
41 views

Is magnetic field changing over the distance?

If we take ONE separate magnet, with lines of the magnetic field coming out of north and going into the south. 1) Does magnetic field change along any of those lines? [ 2) If no (that is what I ...
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0answers
32 views

Magnetic field interaction energy term

I am trying to derive the Ginzburg-Landau free energy for superconductors, and I follow most of it apart from the introduction on the term containing the magnetic field. This is the bit I don't ...
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0answers
27 views

Net magnetic field & magnetization on a ferromagnetic material

A ferromagnetic materiel is saturated by an exterior magnetic field like so: Where $B_1$ is a uniform magnetic field. Then after some time $t$ another magnetic field $B_2$ is introduced as well, ...
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0answers
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What metal can be used as electromagnet core to attract a permanent magnet?

ok. Here are the requirements: 1.The core should not be attracted to permanent magnet when idle(like stainless steel), 2.Should act as electromagnet core with better permeability(like iron). Is ...
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1answer
41 views

Why does a magnet loose magnetic strength when heated?

Magnet manufacturing companies, for example Dexter Magnetic Technologies do not hesitate to explain the effects of heat upon magnets - citing how it degenerates the magnetic properties with levels of ...
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2answers
40 views

The direction of magnetic field- right hand rule

My question is, why is the magnetic force going the same way as the fingers, why not the other way. What causes the magnetic field to choose a direction if everything is symetrical
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1answer
28 views

Magnetic field and magnetic domains

I have a confusion regarding how magnetic field propagate in a medium (ferromagnets or air etc..). It is knows when a ferromagnet is exposed to an external magnetic field, the magnetic domain of the ...
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1answer
30 views

The MRI signal: why do we consider the phase in the MRI signal

I am trying to understand the imaging principles behind MRI and I was looking at some lecture slides found here Specifically, I am looking at slide 41 where we look at some of the equations regarding ...
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0answers
29 views

Attraction between electromagnet and a permanent magnet - at which point is the force the strongest?

You have an air-core inductor with current applied, so that the magnet in the picture will be attracted to it. At what position will the force between the two be the strongest and at which the ...
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0answers
25 views

Would a spinning carbon steel (high magnetic permeability) sphere become magnetized?

Would a spinning carbon steel (high magnetic permeability) sphere "falling" through Earth's magnetic field become magnetized? Would a spinning, evenly charged sphere generate a magnetic field?
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1answer
34 views

What is the reason behind the shape of the magnetic field lines in a circular loop?

Sorry if this question is stupid, but I really need to understand this. I read that in a straight simple wire, the magnetic field lines are concentric about the wire, and the circles become larger as ...
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2answers
35 views

Electromagnetism on a compass [closed]

A current $2\ \mathrm A$ flows in a vertical wire. The value of the horizontal component of earths magnetic field in the region is $2*10^{-5}\ \mathrm T$. A small compass is placed $5\ \mathrm{cm}$ ...
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2answers
42 views

Quantization of the Hamiltonian of a particle in a uniform magnetic field

If a particle of mass $m$ and charge $q$ is subject to a uniform magnetic field and if we have a vector potential $\mathbf{A}$ then we know that classically the dynamics of the particle will be ...
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What is a simple model to find the jump height for the Thomson's Jumping Ring experiment?

I'm trying to devise a basic formula that could give a rough estimate for the jump height reached in the Thomson's Jumping Ring experiment, as detailed here. However, it's pretty difficult as most ...
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21 views

Magnetization of the toroid

As far as I understand, bodies are magnetized by orienting electron spinning within the atoms. Once placed into magnetic fields, they align rotation so that they produce magnetic field in the same ...
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Motion of current carrying rectangular coil in magnetic field

a current carrying rectangular coil is placed in a uniform magnetic field as the plane of coil is parallel to the field at the beginning . assume that there is no restoring torque and no friction. i ...