Magnetic Definition and 1000 Threads

A few simple questions which I am not sure about, it's about NMR. First sentence: "A magentic field B0 is applied on a sample, If the applied magnetic field B0 is stronger, the magnetisation of material is greater" . Would you say that sentence is correct? As I understood, magnetization is a...

I think the real magenetic field is sum of the magnetic fields calculated in each cross section of solenoid with various angle and same center axis when i apply Ampere's law. (Imagine the cross section contains a part of center line of the solenoid) Please let me know why we don't do like that. :)

Homework Statement Are longitudinal magnetic waves possible? Give reasons for your answer. Homework Equations Working with Maxwell's equations, Lorentz force, electrostatic and electromagnetic waves in plasma. The Attempt at a Solution No idea whatsoever. I believe it is possible based on...

Is it possible to make very low frequency EM waves, say 10 KHz, without an antenna the size of Texas? Something more human sized? Thanks.

My question is related to the chapter 10 of L.Sussknd's book on analytical mechanics named "The theoretical minimum". There he considers dynamics of a charged rotor in magnetic field using Hamiltonian formalism and poisson brackets. He also introduces a treatment of the same kind for a...

Homework Statement ok this is not a homework but i am confused by the derivation of ## f = \nabla (m . B)## both start out with ##\vec B(r) \approx \vec B_0 + (\vec r' . \nabla)\vec B|_0 ... \\ f = \iiint_{v'} \vec J( r') \times (\vec r' . \nabla)\vec B|_0 ## where prime is body coordinates and...

Hi, initially I have read that magnetic flux is conserved in iron core, also I know divergence of B is zero but this conservation implies that there is no flux at the interface of air and iron core surface. We still magnetic field even at the interface so there must be flux. Why do we exclude...

Homework Statement A particle of charge -q and mass m enterd magnetic field B at A with speed v1 at an angle alpha and leaves the field at C with v2 at angle beta.Then, a)alpha=beta b)v1=v2 c)particle remains in the field for time t=(2m(pi-alpha))/qB d)All of these Please see image below...

Hello everyone! I'm in my first year of my bachelor in physics and astrophysics at Leiden University, The Netherlands. We have to perform a small experiment were we use a transducer to measure a logarithmic correlation between two certain quantities. As an example our prof. said you could...

Here's a experiment. There is a magnetic field vertically downward and a charged particle is kept inside it. Simple. Does it experience a force? Now if we move a speed of 2m/s relative to the frame of rest charged particle. Then it must experience a force right?(Becuz now its velocity is not...

Homework Statement Consider a spiral of 20 turns with inner radius R and outer radius 2R. If the current is i, find magnetic field at the center of spiral Homework Equations From Biot-Savart law-dB=mu(idl)/4pi*x^2 The Attempt at a Solution Integration seems like a good option. x is...

Hello, For example, an electric field vector, such as the gradient of the potential, passes in the following way to any coordinate system:$$E = -\triangledown{}V = - \frac{{\partial V}}{{\partial x^i}}g^{ij}e_j$$ But what about a vector of a magnetic field? How would it be expressed in any...

I have been revising magnetic circuits concepts and I think I am missing something regarding H-field and mmf. If the 100-turn primary of a transformer is energized with 1A dc, its mmf will be 100A-T. And all the line integrals H.dl enclosing the primary coil will equal 100A. As per magnetic...

Hello community, I can't find an explanation for something and I thought I'd come and ask you. I'm studying for a test I have tomorrow and I came across a problem of a three legged steel core with 400 turns on the center leg, the magnetization curve is given, the first part of the problem asks...

If an electron is moving in a circle in a magnetic field, it produces a magnetic field in accordance to the right hand rule. If a proton is moving in a circle in a magnetic field, would it produce a magnetic field in accordance to the left hand equivalent to the right hand rule.

The reason this is in relativity is ( please correct if wrong )that magnetic fields are effects created by static electricity through length contractions. If a line of electrons move pass a parallel line of positive charges and a charged observer is outside this it would see electrons being...

Homework Statement I tried to understand the problem b) and c).[/B] Homework Equations Faraday's law: ∇xE = - ∂B/∂t emf ε = Bdv Force : F =ma, Lorenz's force F=q(vxB) ==> ma = IdB Power : power of battery = εI, mechanical power of the wire = Fv The Attempt at a Solution I think I solved...

Homework Statement Find the magnitude of the magnetic induction B of a magnetic field generated by a system of thin conductors along which a current i is flowing at a point A(O,R,O), that is the center of a circular conductor of radius R. The ring is in the yz plane. Homework Equations [/B]...

Hi, now I'm working on a project which involves a dc motor and high voltage. I'm developing a machine consists of a motor to rotate a platform disc and high voltage will be applied during the rotation. The problem is when I supply a positive high voltage at motor shaft during rotation, the motor...

Homework Statement You observe a molecular cloud core with the following properties: T = 5K R = 1pc M = 10 M⊙ n = 102 cm^-3 B = 1µG RΩ = 200 cms^-1 A. Assuming equipartition of B fields and turbulence, what is the turbulent velocity of the cloud? Homework Equations Emag=1/6((B^2R^3)/μo)...

After reading about Jupiter's magnetic field on ScienceAlert, I remembered another article about tree bark and magnetic anomalies (links below). I also remembered an article on birds being able to see magnetic fields as well. It got me thinking of how and if life is possible on anything other...

Homework Statement [/B] I am working on a experiment on finding the Earth's magnetic field strength in Denmark. Using a Galvanometer and a constant power source of 5.1V and slowly adjusting the resistance, I was able to find the changes in angle in relation to the changes of current. 2...

I was wondering if it was possible to create any shape of magnetic field. If yes, what would it take to do so?

Homework Statement In the figure, an electron of mass m, charge − e, and low (negligible) speed enters the region between two plates of potential difference V and plate separation d, initially headed directly toward the top plate. A uniform magnetic field of magnitude B is normal to the plane...

https://phys.org/news/2018-08-image-sun-magnetic-field.html#jCp These fields are generated by the solar wind? By the sun spinning does it generate another mag field? Is this a good example of how hot objects loose their coherent magnetic field by misaligned temperature generated ad hoc domains...

Consider the magnetic field B generated by a magnetic dipole. The intensity of B measured along the axis of the dipole, at a distance of 10 cm from the dipole itself, is 1.0 10-5 T. What is the size of the magnetic dipole moment? (μ0 =4π10-7 mkg/C2) a) 0.050 Am2 b) 5 10 -4 Am2 c) 0,1 Am2 d) 1 10...

Magnetic Lorentz force is the force experienced by any charged particle moving in a magnetic field.i want to clarify some doubts regarding this topic of Magnetic Lorentz force.some of them are: 1. Is it the Lorentz force that is actually responsible for the phenomenon of electromagnetic...

If I have a magnetic field describing a closed path it means that this closed path is surrounding a current, right? But if I have no current, is it the displacement current ? I'm thinking of a magnetic dipole, its magnetic field describes closed paths from its north to south pole, so is there a...

I was solving some problems from a textbook and I found this formula for the radial dependence of the sun's magnetic field, ##B(r) \approx B_{\odot} \Big(\frac{R_{\odot}}{r}\Big)^{1/2}##, where ##B_\odot \approx 0.001T## is the magnetic field strength in the photosphere. But how can this formula...

I'm trying to understand electric and magnetic transitions in gamma decay a bit more intuitively than i currently understand but I'm having a really hard time doing so When the nucleus is coupling to the electric field of the photon we call it an electric decay and the parity is: (-1)L When...

Homework Statement [/B] I'm stuck on part (b) and (c) of the following question Homework Equations The Attempt at a Solution The partition function was ##Z_N = 2 cosh(μBβ)## where ##β = \frac {1}{kT}##. From there I used ##U = - \frac {∂}{∂β} ln (Z_n)## to get ##U = -NμB tanh( \frac...

Homework Statement Homework EquationsThe Attempt at a Solution I know that, according to the right hand rule, the direction of the field lines for X and Z are anti-clockwise and Y is clockwise. What do I do next? Thank you!

I have a question regarding the interactions of electromagnetic fields. Say you have two superconducting electromagnets A and B. The properties of the magnets are known such that you can tell precisely how quickly it takes each one to produce it's full strength magnetic field and how long it...

<Moderator's note: advertisement link removed.> So I was making a research and would highly appreciate your help. I am making a research about car magnets as to how it is being made, materials, etc. any additional information from you would highly be appreciated...

Don't know if this is the right place to post this, but it seemed like the best place to start. I'm wondering how much stronger would the Earth's magnetic field need to be in order to make quantum levitation using Earth's magnetic field alone a possibility. Bonus: Effects the change in strength...

Homework Statement I am trying to solve a problem that I have invented. It consists of a metal stick of mass m, which falls by the action of gravity (g=constant) within a perpendicular constant magnetic field B. The direction of magnetic fiel is showed in the image. The stick makes electrical...

Hi all, Not a question about completing homework here, but I'm a teacher looking to create a realistic engineering question for an assignment. I have an engineering scenario I've set for the assignment which is a junior engineer working for a marine engineering company so all of the questions...

Homework Statement A proton is projected perpendicularly into a magnetic field that has a magnitude of 0.30 T. The field is then adjusted so that an electron will follow a circular path of the same radius when it is projected perpendicularly into the field with the same velocity that the proton...

Homework Statement One component of a magnetic field has a magnitude of 0.0431 T and points along the +x axis, while the other component has a magnitude of 0.0686 T and points along the -y axis. A particle carrying a charge of +1.70 × 10-5 C is moving along the +z axis at a speed of 4.24 × 103...

I cam across SMES (Superconducting Magnetic Energy Storage) while researching superconducting and had a few questions I'm hoping to have answered. 1. I have read that SMES devices are primary used in the event for short interruptions in power, and aiding in efficiency in the power grid. Can a...

Homework Statement Two straight rods 60 cm long and 2.0 mm apart in a current balance carry currents of 18 A each in opposite directions. What mass must be placed on the upper rod to balance the magnetic force of repulsion? ## \mu_0 = 4 \pi * 10^-7 ~\frac {T * M} {A}## ## g = 9.81 ~m/s ##...

I was looking at some works by the members of my university physics departament and I found this one <Mod edit> Besides this abstract, the paper is in Portuguese. <\Mod edit> http://lilith.fisica.ufmg.br/posgrad/Dissertacoes_Mestrado/decada2010/denis-oliveira/DenisDaMataOliveira-diss.pdf...

There is a solenoid of a certain radius, carrying a certain current. I draw an amperian loop of radius greater than the radius of the solenoid. If I calculate the total flux through this loop it should be, 1) Non zero for an ideal solenoid (where the field outside the core of the solenoid is...

What if an electromagnet's core is on the outside? How would it's magnetic field look? (The wire being wrapped in coils on the inside of a tube or pipe looking metal)

If your fingers of one hand curl around the axis of rotation of the accretion disc of a massive black hole and your fingers point in the direction of the flow is the direction of the central twisted poloidal magnetic field given by a right hand rule, a left hand rule, no rule? Is there a simple...

Very recently, Roger Penrose, along with Daniel An and Krzystztof Meissner, have submitted a new paper to PRL. In the new paper they present new empirical findings which support CCC. It doesn't seem to be out yet though, I can't find it anywhere, but I will place the link here when it is out...

Homework Statement A straight wire of length 0.20m moves at a steady speed of 3.0m/s at right angles to a magnetic filed of flux density 0.10T. Use Faraday's law to determine the e.m.f. induced across the ends of a wire. Homework Equations E= Nd Φ/dt but N=1 so E= dΦ/dt The Attempt at a...

Could anyone point me to the proper formula to calculate the magnetic field strength in the gap/hole(ID) of a diametrically magnatized ring magnet. https://www.skycraftsurplus.com/rp9291magnetdonut17odx08id-1.aspx

Hello! I am confused about the first EM problem on http://web.mit.edu/physics/current/graduate/exams/gen2_F00.pdf (page 4, with the cylinder in a magnetic field). The solution can be found http://web.mit.edu/physics/current/graduate/exams/gen2sol_F00.pdf. In part a the solution is...

What happens to the velocity? Say we have a piece of space debris in free fall. It has a particular velocity at a given time. Then say at some later time it's bombarded with ionic gas or something that causes it to become charged. Does the velocity change? My guess would be yes, because the...