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
22 views

Applying Ampere's Law for Two Parallel Wires

This seems a simple question but I'm not able to understand it properly. Say we have two parallel wires carrying same current I in different directions. We need to calculate the magnetic field at any ...
-1
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1answer
36 views

Can I use an electromagnet as a shark repellent? [on hold]

I scuba dive, and also spearfish. Doing these sports in the ocean presents obvious challenges since Sharks exist in the ocean. I know about a product called shark shield which uses magnetism to ...
1
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1answer
27 views

Mechanical, not voltage driven electron motion creating larger net electromagnetic force

Have mercy I'm a physician not a physicist. Electrons' Motion in an electromagnet is on the order of 10$^{-4}$ m/s. That charge can be mechanically rotated in a capacitor with a million times more ...
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0answers
76 views

Why did Kepler thought that the Earth was hollow? [on hold]

I was researching a little about the theory of the hollow earth, since I am a mathematician I don't understand well about physics some famous scientific thought this namely Euler, Edmond Halley and ...
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1answer
20 views

Does magnetic lines keep moving continuously once the magnetic field is created or they become static? [on hold]

Does magnetic lines keep moving from north pole to south pole outside the magnet and from south to north inside the magnet or they are static once they are created. If the move then why don't the iron ...
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3answers
472 views

What is the relationship between the magnetic units oersted and tesla?

How are the units oersted and tesla related? For example, how would you express $20\:\mathrm{Oe}$ in tesla?
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0answers
22 views

What force is needed to slide a plate off a magnet?

I have read related the wiki article but I am not able to find a solution to my problem: how to find the min force needed to separate a magnet. I suppose that the force exerted by one magnet is ...
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0answers
21 views

Can Fluctuation-Dissipation Theorem Apply to Magnetic Forces in Multi-Spin Systems

Let's say I have multiple spin systems (atoms in a protein) in a solution of water and the spin systems are all producing a magnetic field $\mathrm{B_{loc}}$ that affects nearby spin systems. Will the ...
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0answers
11 views

Is it necessary that the field in a top trap rotates? Difference top trap/Ioffe trap

Because of majorana losses it is necessary to add a bias field in order not to lose too many atoms. But it is it really necessary for the bias fiald to rotate like in a top trap or would it be enough ...
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1answer
37 views

Motion of charged particle in uniform magnetic field

To create a uniform magnetic field I took a current carrying solenoid connected to a battery, then I took a long straight wire connected to another battery, the wire passes from inside the solenoid. ...
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0answers
23 views

Charging Copper ball bearing

I want to conduct an experiment to observe the trajectory of charged particles in applied magnetic and electric field. Thus, I want to charge a copper bead/ball bearing. How can I electrically charge ...
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2answers
61 views

Will rotating magnets slow down one another when interacting?

Will rotating magnets slow down one another when interacting? Two discs are spinning. Both have separate magnets attached. Disc one has a diameter of $8~\mathrm{cm}$ and disc two has a diameter ...
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1answer
19 views

Does the direction of magnetic field in a solenoid point from north to south anywhere? [closed]

Is there any case where the direction of magnetic field inside a solenoid points from its North Pole to its south?
3
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1answer
101 views

Find magnetic field of parabaloid-spiral particle path

Given the components of the particle's path (tcos(at), tsin(at), R(x^2 + y^2)), where a and R are constants, how can I find the magnetic force causing this? I would like to understand if this can be ...
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3answers
62 views

Electron deflected by moving magnet

My original question was far too long, so I am editing it down to this much smaller version: The Lorentz force for an electron traveling through a uniform magnetic field with no electric field is $F=...
-1
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0answers
19 views

Does removing half of toroidal ferromagnetic core significantly reduce flux density in the remaining half?

Assuming a DC current in a cable has induced a magnetic field around the cable, and a ferromagnetic toroid is used to concentrate the field; if half of the toroid were cut away (so the cable is no ...
0
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1answer
38 views

Why can't weak core-less electromagnets be used in conjunction with strong permanent magnets to perpetually harvest energy?

Why can't weak core-less electromagnets be used in conjunction with strong permanent magnets to perpetually harvest energy? Magnets will attract ferrous materials but some materials like copper or ...
2
votes
2answers
63 views

Why would a moving infinite region of magnetic field exert an electric force?

I'm confused about the Lorentz force in relation to the frame of reference. There are many questions about that here, but I still don't get it. I've tried to break it down to the most basic example. ...
0
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1answer
41 views

When to apply $\frac{mv^2}{r} = q .v .B$

A charged particle of mass $m$ is moving with a speed $u$ in a circle of radius $r$ . If the magnetic field induction at the centre is $B$ and the charge on particle is $q$. I want to know why I can't ...
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0answers
13 views

Will non-ferrous materials like Gold that have been magnetised by a slight electric current become attracted to much more powerful permanent magnets?

If a magnet interacts with Gold it will magnetise it to a very slight degree but if the gold is in turn magnetised by passing a generally weak current through it will the gold more easily attract ...
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1answer
24 views

Mag.-flux build up…hate it

"An old bell ringer". After a few minutes of running, the steel pole of transformer, slowely becomes magnitized. Are there any unique metals that would prevent the mag.-flux build up, in the steel ...
3
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1answer
43 views

Electron traveling through gravitational and magnetic field

When an electron travels through a magnetic field it experiences the Lorentz force. The force acting on the electron causes an acceleration and therefore Cyclotron radiation is emitted. After reading ...
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2answers
40 views

How strong is Earth's magnetic field in space?

I've been searching around Google and Youtube about the strength of Earth's magnetic field. By the help of wikipedia, I have found out that it's magnitude is 25 to 65 microtesla or 0.25 to 0.65 Gauss ...
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2answers
31 views

How to prevent magnetic field from generating in current carrying conductor?

Is there anyway to prevent generating magnet field or nullify it.
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0answers
24 views

superposition of two magnets

If I have two magnetic particles at x and y axis with strengths* $\mu_{x}$ and $\mu_{y}$; and another magnetic particle in x-y plane with strength $\mu=\vec{\mu}_{x} + \vec{\mu}_{y}$,then will the ...
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2answers
35 views

Instantaneous transfer of information?

If suppose there is some charge which is not under influence of any other thing. Let us for observation surround this charge with circles of pointers pointing in the direction of its field. If I move ...
6
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1answer
135 views

What force causes the induced EMF of a loop? And, the difference between a loop EMF to motional EMF?

If a loop of wire is placed perpendicular to a changing magnetic field, there is an induced EMF such that the induced current is flowing in a direction to create an opposing magnetic field like this ...
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3answers
42 views

Is the South Pole of an electromagnet always at the end where current is drawn into it?

I'm trying to determine in which direction a magnetic field will be produced in regards to the direction of current in an electromagnet. Will the end of the electromagnet from which current is drawn ...
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0answers
40 views

Why human body is not affected on magnetic field?

Electric-current easily cause shock to human body. But magnetic fluxs through human body do-not cause any perceptible change, as-well no invisible-impacts/ health impacts are well-known. We, when hold-...
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0answers
11 views

Determining pole strength experimentally

Could anyone give me a quick explanation of what magnetic pole strength is or a website that does so? Also, how can i determine this value experimentally? Thanks in advance
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0answers
25 views

Bowl Shaped magnetic fields responsible to keep galaxies together?

David LaPoint released some videos on youtube. In part 2 he claims that because galaxies look similar to the shape of plasma created in his experiment they must be shaped also by external magnetic ...
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2answers
19 views

Can we isolate the iron ions in a solution?

I was wondering if it was possible to isolate the iron ions in a soltion without adding anything (to precipitate for example). Maybe using a magnetic field? Thanks
0
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1answer
20 views

Differences between a field, its field strength, and the force an object experiences within this field

My question is what are the conceptual and intuitive differences between these things. For example, the magnetic field B = F/(|q|v). In this case, B IS the field, and when a charged particle is ...
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0answers
15 views

Magnetism loss in temporary magnets

There are many types of methods and materials to create a temporary magnet out of a non-magnetic piece of metal such as iron,nickel ect..but what makes them temporary? Heat,a high velocity impact to ...
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0answers
18 views

Magnitude of the Magnetic Force between magnet and metal

How does one calculate the force with wich a magnet (or magnetic field) attracts a feromagnetic object? Is there an equation i can use? Thanks
4
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1answer
111 views

Why didn't Newton study electricity and magnetism?

This is a soft question about the history of physics. In Newton's time, electrical and magnetic phenomena (such as amber attracting things or the alignment of compass needles) were well known. Yet I ...
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0answers
12 views

Finding torque on a current carrying loop with respect to different points?

So how does the torque varies wrt different positions. Like if I'm trying to solve a question with a rod hanging with wires and a current carrying loop in between, how do i write the torque with ...
0
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1answer
23 views

Neutron in a magnetic field (Schrödinger Equation, Eigenstates, Eigenvalues).

Consider the spin of a neutron in a magnetic field $\vec{B}$. A neutron is a neutral particle with the mass of a proton and the spin $\frac{1}{2}$. The Hamiltonian is $H=\mu_n\vec{S}\cdot\vec{B}$...
3
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1answer
78 views

Can Non-Magnetic Dust Particles become magnetic if their particle size is decreased (by grinding them probably)?

Problem: Take some dust particles whose size is big. Bring a magnet near them. They do not get attracted to the magnet and thus we conclude that they are non-magnetic. However, when you grind the ...
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0answers
13 views

Create spinning / modulating plasma effect without spinning the whole appartus

I'm trying to create a variable spinning / modulating plasma effect without turning the whole apparatus as seen in the video. https://www.youtube.com/watch?v=Wis_HEa3X84 Is it possible to just use ...
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0answers
15 views

Plasma generated with gas and how far does it penetrate the skin

I know Far Infrared can penetrate the body’s tissues 1.5 inches (almost 4 cm) beneath the skin. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699878/ But how far will a plasma field generated with ...
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0answers
21 views

How can I deposit NdFeB film on aluminium?

I want to coat a permanent magnetic material(NdFeB film) on a aluminium beam by means of sputtering or evaporation method. Is it possible? Any related journals pls attach.. Thanks in advance.
1
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1answer
63 views

Can we derive Biot Savart law from Coulomb's law?

Can we derive Biot Savart law from Coulomb's law by setting a current source at an instant in place of one of the charges? Let's say $dl$ is the length of the conductor having $dQ$ charge which ...
3
votes
2answers
58 views

Moving of spin up and spin down electrons in a magnetic field [closed]

Suppose we have an electron in a conducting space, and now we apply a magnetic field. Now according to the right hand rule, the electron will have a circular motion in the plane perpendicular to the ...
0
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1answer
37 views

How can a sinusoid be a steady current? [duplicate]

As far as I understand it, a steady/stationary/constant current is defined to have $dJ/dt=0$ (i.e., no explicit time dependence). So I would say that sinusoids cannot produce steady currents, yet ...
1
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1answer
48 views

Quantum state after change of magnetic field

I have the following conditions: $\lvert\psi(0)\rangle=\lvert+\rangle_x=\frac{1}{\sqrt{2}}\lvert+\rangle+\frac{1}{\sqrt{2}}\lvert-\rangle$. So the state at $t=T$ is $\lvert\psi(t)\rangle=\frac{1}{\...
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0answers
27 views

What difference does it make if the turns in a tesla coil overlap?

Would a tesla coil in which the primary coil is made by overlapping the turns of the wire work?
4
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1answer
53 views

Why do the magnetic poles of the Earth get reversed?

It has been confirmed that the magnetic poles of the Earth get reversed , but why should they get reversed in the first place ? Also, why is their pattern of reversal so arbitrary ? Geomagnetic ...
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2answers
64 views

Energy of electric field and magnetic field

I am studying about inductors and capacitors. They store their energy in the form of electric field and magnetic field.Energy is required to create fields.But if we take an isolated charge and nothing ...
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1answer
38 views

How to create a strong magnetic field using permanent magnets

I would like to build a strong magnet using 100 6"x4"x1" permanent magnet blocks. What is the best way to place them so I get the strongest magnetic field? (Should I stack 2 row of 50 blocks and put ...