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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1answer
93 views

Do iron bar become heavier when magnetized?

Say I have a piece of iron bar, would the same iron bar weights more when being magnetized asumming no outside forces like magnetic field etc and the scale is non magnetic, I think you know what I'm ...
0
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1answer
66 views

How to 'smooth/flatten' the surface of a disturbed liquid

I would like to essentially flatten or smooth the surface of a viscous liquid after dropping an object into it, without actually touching the liquid. For example, if I drop a rock into a tub of oil, I ...
1
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1answer
64 views

What does radiofrequency really do in NMR & MRI?

In NMR, the protons’ frequencies are affected by the magnet which makes them precess around its magnetic field so now all protons will have different frequencies according to their environment ...
3
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3answers
139 views

Which elementary particles are behind magnetic field, similar as photons behind radio waves?

I see, there are photons behind radio waves. As Wave–particle duality said: the radio waves are waves and at the same time are fluxes of particles called Photons. I'm wondering, what is behind ...
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0answers
51 views

As the World Turns [closed]

Does the Earth's axis change with the magnetic reversal as it is taking place?
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0answers
27 views

How to calculate the maximum spacing between Hemholtz coils

I would like to design a long, uniform magnetic field using Hemholtz coils but am not sure how far I can separate them before the field lines diverge and become two loops that go around each coil ...
0
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1answer
206 views

Earth Maybe a Compass or Not [closed]

Does the Earth magnetic pole point to something in our solar system or farther? Like the Sun.
4
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1answer
108 views

Why is the magnetic field of a spherically symmetric current zero?

We now ask about the magnetic field produced by the currents in this situation. Suppose we draw some loop $\Gamma$ on a sphere of radius $r,$ as shown in Fig. 18–1. There is some current through ...
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1answer
40 views

Permanant Magnet Lines & Currents: [duplicate]

A permanent magnet produces lines of magnet flux that we call a "magnetic field". Those lines come from inside the magnet, come out of the N pole, loop outside the magnet, & return back into the ...
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2answers
56 views

Permanent Magnet Lines & Currents:

A permanent magnet produces lines of magnet flux that we call a "magnetic field". Those lines come from inside the magnet, come out of the N pole, loop outside the magnet, & return back into the ...
0
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1answer
58 views

Magnetic force of a magnetic field around a wire

Suppose we have a magnetic field around a wire because there goes a current through the wire. Suppose there are not any magnets near. Is it ture that there is then also a magnetic force? If so, is ...
0
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1answer
65 views

Does current in a part of a wire create magnetic field at any other part of the same wire?

Let there be a circular-shaped wire - a ring in which there exists a steady current. It creates magnetic field around the wire. This can be evaluated by Biot-Savart Law. As shown in the fig., ...
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0answers
20 views

Calculating the deflection of an electron in a given magnetic field [closed]

I have been stuck on this question for some time but I am not able to solve it. It is a question from "Concepts of physics" (2nd volume) by H.C. Verma. An electron is projected horizontally with a ...
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0answers
36 views

How to create linear parallel magnetic field lines

I am trying to make ferrofluids create a flat surface between two points. Most of the magnet configurations I have seen have field lines that arc. So I'm asking if there are any circumstances where ...
0
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1answer
79 views

What is the speed of magnetism?

I'm not a physicist (just have a few basic notions) and this is a question out of curiosity, so as I'll probably word it the simplest I can, please take that into account when answering. tl;dr Let's ...
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0answers
33 views

Ferrofluids and normal-field instability

Could someone explain whether the spikes and uneven surfaces you see in ferrofluids being attracted or repelled away away from (against gravity) the surface of ferrofluids would happen if the fields ...
3
votes
2answers
54 views

what happens to a magnetic field when it moves relative to an observer at relativistic velocities?

what happens to a magnetic field when it moves relative to an observer at relativistic velocities? Does it become an electrical field?
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2answers
43 views

Electropermanent Magnet not working?

I have made an electropermanent magnet based on summary provided on this blog. Here are my details - I have used AlNiCo and Neodymium Magnet together in the core with 10mm diameter and 20mm length. ...
0
votes
1answer
41 views

How to calculate the magnetic flux through a circular area [closed]

A constant magnetic field passes through a circular area (of a solenoid). I'm trying to calculate the flux using $$\phi_B= \int B dA$$ $B=0.2$ Tesla, Diameter of the solenoid (and therefore circle) ...
3
votes
1answer
32 views

Why does cutting slots in metal improve magnetic flow?

When machinists mount work pieces for grinding they often use magnetic chucks and fixtures are set on those chucks. The thicker the fixture, the more the magnetism is attenuated. Sometimes that is a ...
7
votes
1answer
265 views

Motion in a time-dependent uniform magnetic field

Suppose you have an infinite solenoid generating an uniform magnetic field inside. The field is oriented along the solenoid axis : unit vector $\vec{\bf n}$. The field intensity varies linearly with ...
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1answer
36 views

Torque as if magnetic force were concentred in mean point

From what I see in my textbook and several on line resources (such as this, p. 8-8), I am tempted to think that the magnetic force $I\boldsymbol{\ell}\times\mathbf{B}$ acting on a straight conducting ...
-1
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1answer
43 views

What is the magnetic field at a distance along the axis of a strictly elliptical solenoid? [closed]

And at what rate does it decay as we move perpendicular to the axis?
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1answer
98 views

How force get transmitted when a magnet attracts iron?

According to particle physics , every fundamental force has its force carrier particle. Photon is a force carrier particle of electromagnetic force but how does force gets transmitted when a iron is ...
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0answers
27 views

Does a permeable core increase flux or only concentrate what's already there?

I understand that that introducing a high-permeability core (say iron) into an air-core coil (having some current running through it) increases the flux density $B$ in the core. Does the iron core ...
4
votes
4answers
105 views

About the uniqueness of the displacement current

In the Maxwell-Ampère equation, i.e.: \begin{equation} \nabla\times\vec{B} = \mu_0 \vec{J} + \mu_0\epsilon_0 \frac{\partial \vec{E}}{\partial t} \end{equation} the $\vec{J}_d$ term: $$ \vec{J}_d := ...
2
votes
0answers
31 views

Strongly Influencing Electric & Magnetic Field Forces:

Why is it easier to block electric field forces than magnetic field forces in close ranges to the source? What is the best way to block, redirect, and minimize the strength of half of the lines of ...
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2answers
84 views

Torque due to magnetic force on a loop

I read that the torque due to the force exerced by a uniform magnetic field $\mathbf{B}$ on a closed conducting rectangular loop is $$\boldsymbol{\tau}=I\mathbf{S}\times \mathbf{B}$$where $\mathbf{S}$ ...
3
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3answers
347 views

Do moving charges get affected by the magnetic field they create while moving to constitute current? If not, how can self-induction be possible?

Let a bunch of charge move with a constant velocity $\mathbf v\;.$ Since, the charges are moving, they would create magnetic field $\bf B$ as it is current that produces magnetic field. Now, would ...
0
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1answer
24 views

Magnetic force on a wire: how to calculate it

I read in my book of physics, E.W. Gettys' Physics 2, that the magnetic force acting on an "infinitesimal segment" $d\boldsymbol{\ell}$ (I apologise for such language, often used in elementary physics ...
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1answer
32 views

Shift in pixels between 2 tissues in MRI

I have the following question: given a known chemical shift $\delta$ between 2 tissue proton resonances and a MR image sequence with a total spin-echo sampling time of $t$ ms, what is the spatial ...
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1answer
87 views

Finding the force between parallel currents using the formula of magnetic pressure

Let there be two parallel current-carrying infinitely-long wires separated by $d$ carrying currents $i_1$ & $i_2$ respectively in the same direction. In order to find the force on an ...
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0answers
31 views

Does curvature of space affects magnetic field?

I just want to know can strong gravity such as a black hole bends magnetic field lines?
3
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2answers
108 views

How can a sheet carrying current get affected by its own magnetic field?

I was reading ' Change in B at a current sheet ' in Electricity & Magnetism by Edward M Purcell. this is the concerned excerpt: Consider a square portion of the sheet, $1~\text{m}$ on a side. ...
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0answers
44 views

How to calculate motor torque & rpm

I watched a DIY video recently about a brushless DC motor. How would one go about calculating the max torque & max rpm (under no-load & a given load conditions) of that motor based on the ...
0
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2answers
78 views

Levitation using Electromagnets - Forces

Here is a hypothetical (but potential real) situation: I am holding electromagnet that weights 1kg. This electromagnet is being used to hold up a 10kg weight. Would I feel like I am holding 11kg, or ...
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0answers
26 views

Fréedericksz transition question

What is the lowest voltage needed for a Fréedericksz transition to occur?
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2answers
44 views

A Magnetic Path?

I've noticed an amazing phenomenon while playing around with magnets, pulling them apart requires tremendous force(like with neodymium magnets). However, slidning them apart requires a lesser(greatly) ...
0
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2answers
43 views

Field due to a moving magnet

Say you are in a fixed reference frame. Bob, is in a moving reference frame. Also, Bob has a bar magnet. If Bob were moving toward you with a magnet, would the value of the magnetic field you measure ...
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0answers
24 views

What is the general proof that the torque acting on an irregular current carrying loop in an uniform magnetic field is only dependent on area?

How do you prove that the torque acting on an irregular current carrying loop in an uniform magnetic field in the plane of loop = $I \vec{A} \times \vec{B}$ Where, $ \vec{A}$ = Area vector of the ...
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0answers
43 views

Will matter vibrating at THz frequencies emit light?

Much like a magnet creating an alternating current when slid through a solenoid, will matter that vibrates at 500 THz create lightwaves? Here we are talking about taking an object which doesn't glow ...
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0answers
46 views

What's the formula to determine how fast a magnet can travel and still hold objects in it's magnetic field?

If an object (an iron ball) is locked (suspended) in the magnetic field being produced by a magnetic bar, what is the maximum velocity at which the bar can be moved before the iron ball is disturbed ...
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1answer
47 views

Auxiliary magnetic field identically zero?

Consider a 3D space that's filled up completely with a material of fixed magnetization $\mathbf{M}$ (i.e. everywhere in space the magnetization points in the same direction and has the same ...
0
votes
1answer
68 views

Can iron core from solenoid be diamagnetic?

So... we were measuring RLC circuit, and while we inserted core into solenoid, the amplitude on osciloscope decreased. It would imply, that the core is diamagnetic. But it is original core from PHYWE ...
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1answer
43 views

Can the use of a magnetic compass be inconsistent with Galileo's Relativity Hypothesis?

I just read Galileo's Relativity Hypothesis from this website: http://physics.ucr.edu/~wudka/Physics7/Notes_www/node47.html It states that - "any two observers moving at constant speed and direction ...
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2answers
32 views

Calculate magnetic field from magnetic force on a charged particle

The magnetic force, charge, and velocity of a particle are given. I am asked to find the magnetic field. $$q = -2 \,\mathrm{\mu C}$$ $$\vec{v} = (-\hat i + 3\hat j) \times 10^6 \mathrm{m/s}$$ ...
0
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2answers
60 views

Magnetic field at the center and ends of a long solenoid [closed]

A long solenoid has current $I$ flowing through it, also denote $N$ as the turns per unit length. Take its axis to be the $z$-axis, by symmetry the only component of the magnetic field inside is ...
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2answers
284 views

why don't large magents repel themselves

This question may have been asked before so I apologize in advance if it has. I've been playing with some magnetic buckyballs I got recently (highly recommend getting some if you dont have any) and ...
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2answers
129 views

Can pulsating DC current be transformed?

Since pulsating DC current is changing, why doesn't it induce a changing magnetic flux in the transformer core? Is it able to induce a transformed current in the secondary coil?
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0answers
18 views

Are magnets attracted to mu-metal?

Are magnets attracted to mu-metal? Be aware that when watching videos of mu-metal they may have metals that are attached to the mu-metal and are attacted to magnets. Please don't get them confused.