Magnetic field Definition and 1000 Threads

Homework Statement 3. A spherical conducting shell is placed in a time-varying magnetic field. Is there an induced current along the equator? Homework EquationsThe Attempt at a Solution I don't know what is the right answer. I mean...why not? Is the magnetic field is changing, there should be...

Homework Statement A DC current is flowing between two electrodes through a iron disk medium. Positive is attached to the copper shaft of the disc and the negative is attached to the outer brass periphery of the disk. The radius of the disk is 2,54mm (1 inch) and the height of the disk is 1cm...

So I was trying to see what the result for the spin precession would be if the magnetic field pointed in the y-direction instead of z. I feel like either something with what I'm doing is wrong or, I'm just overlooking something because I keep getting complex energy eigenvalues. So what I'm doing...

Homework Statement A wire carrying a current I in the positive x direction is located along the x axis. The wire is of finite length and is located between x = -L and x = L. Find the magnetic field at a field point located a distance a away from the wire. Homework Equations Biot-Savart law...

Hello, could someone help answer this question for me: How would the path of a conducting sphere (i.e. AL) be affected as it passes through a strong uniform magnetic field orthogonal to the direction of motion. I believe the Lenz effect/Eddy currents will create a magnetic field opposing the...

I know, geologicaly speaking, that "suddenly" is a relative term. So when they say that Earths magnetic field suddenly switches, how long are we talking about. Days, hours, centuries?

When a nucleus is placed inside an external magnetic field, it aligns itself parallel to the field, as that is the most stable position for it to be in. In more technical terms: it acquires an alpha spin. When you shine radio waves at this nucleus, it absorbs energy and flips over anti-parallel...

Homework Statement Hello all, not really sure what to title this. Heres the question: Ceicil sets a trap. According to ceicil, all she has to do is somehow attach a conductive bar with resistance 1Ω to the turkey and then get it to walk along a wire loop in a region of 100T magnetic field (as...

Homework Statement A metal strip 6.5cm long, 0.88cm wide, and 0.76cm thick moves with constant velocity, magnitude v along positive y-axis, through a magnetic field, B=1.2mT along positive z-axis. A potential difference of 3.9x10^-6V is measured between points x1 and x2 (as shown in...

Greg Bernhardt submitted a new blog post Are Magnetic Field Lines Real? Continue reading the Original Blog Post.

The Earth's magnetic field is cylindrically symmetric and can be described using cylindrical coordinates, (ρ,z,φ). The components of the magnetic field are given by: (B_φ) = 0 (B_ρ) = −∂A/∂z, (B_z) =(1/ρ) * ∂(ρA)/∂ρ. The vector potential for a dipole field is given by (A_φ) = (B_e)(ρ) *...

Dear all. I would like to know the general expression of the ratio of the electric field strength E to the magnetic flux density B. I know E/B = c, where c is the speed of light, for a vacuum, but I want to know if this is stil valid for any material where the electric and magnetic fields are...

Homework Statement Find the magnetic field at point P. (P is at the centre of two infinitely long wires, carrying current in opposite direction. Homework EquationsThe Attempt at a Solution My guess is that since the current direction is opposite and distance between the point and the wires is...

Homework Statement In the figures below, a copper wire of circular cross section, A, has been bent into a square loop of side length, c, and arc welded at the seam for electrical continuity. Assume that the resulting square loop has a resistance, R, and a mass, M. The loop is originally held...

Homework Statement A deuteron nucleus (consisting of one proton and one neutron) has a mass of 3.34x10-27kg and a charge of 1.602x10-19C. The deuteron nucleus travels in a circular path of radius, 6.6mm, in a magnetic field with magnitude of 2.1T. A) Find the speed of the deuteron nucleus B)...

I tried to calculted the rotating speed fro a proton from the clasical point of view by using its magnetic moment and the moment of a rotating sphere uniformly charged as example here: https://ocw.mit.edu/courses/physics/8-07-electromagnetism-ii-fall-2012/exams/MIT8_07F12_quizsol2.pdf It is said...

Today I came across an article (not from a authoritative journal) about "Quantum Navigation". https://www.wired.com/story/quantum-physicists-found-a-new-safer-way-to-navigate/ It is about a method to do navigation by detecting anomalies in Earth's magnetic field. I tried (and failed) to find a...

I have a thin copper tube of 4.4mm inner diameter (inside a long ionizer plasma cannon) and I want to fill in with hydrogen plasma fully ionized at low temperature (100eV), what is recommended magnetic field to have the ions there without touching tha walls? The plasma life is about 0.5 seconds

Homework Statement The figure below shows a small circular loop of wire in the plane of a long, straight wire that carries a steady current I upward. If the loop is moved from distance x_2 to distance x_1 from the straight wire, what will be the direction of the induced current in the loop and...

Homework Statement A rod with mass of m runs on rails in a magnetic field. The rails are connected with a wire at x = 0 so that the rod and the rails together with this wire form a closed circuit. The distance between the rails is L, and the resistance in the rod is R. We assume that the...

I am trying to find a way to decrease the force between two magnets by putting a physical barrier in the middle of them. I’ve reasearched and found that Mu metals redirect the flux of the magnetic fields so those two magnets shouldn’t have any noticeable attraction between them. Of course...

Can someone help me to understand some of these steps? Why can we write ##\frac{1}{R} = \frac{sin(\phi)}{R}## and ##y = - cot(g\phi)##?

I have the first and second orders that I use in a magnetic simulator, but i need the thirth also to do also with magnetic cylinders accordingly paper: Do anybody have it in any code? I should pass to C++

I do not understand the theory of moment of nuclei I read here: http://www.sjsu.edu/faculty/watkins/nuclearmoment3.htm that the magnetic moment of Hydrogen is 2.79284734 magnetons = 2.79284734*9.274009994e-24 joules/tesla =2.59e-23 joules/tesla So if I make to rotate a proton using 150 keV...

I used the following links: C++ software using elliptics integral at: https://tiggerntatie.github.io/emagnet/offaxis/elliptic_c.htm And the calculator here: https://tiggerntatie.github.io/emagnet/offaxis/iloopcalculator.htm I placed some values and obtained Br smaller than Bx, so I do not know...

Homework Statement What causes electric field? What causes magnetic field? (I) stationary electric fields (II) moving electric charges (III) a changing magnetic field IV) a current-carrying wire Homework Equations E=F/q B=μI/2πr E electric field F elecric force Q charge B magnetic field I...

Homework Statement An electron moving in the -z direction enters a region that has a uniform magnetic field in the +y direction. When the electron enters this region, what direction will it be deflected in? Homework Equations F=qv X B The Attempt at a Solution I tried answering this question...

Hi all. I am alluding to the Moving Charge in a Magnetic field problem by quoting an MIT lecture below. Scott Huges – Lecture http://web.mit.edu/sahughes/www/8.022/lec10.pdf Suppose we now examine this situation from the point of view of the charge (the “charge frame”). From the charge’s point...

Hi Please help me in understanding the kind the magnetic field used in an AC generator. Most of the figures (one shown in attached file) are shown with concave poles. Hence the field has to be radial. In such a field the angle between plane of coil and the magnetic field remains zero all the...

Hi all. I was wondering if time is dilated whilst traveling in a stable magnetic field that is generated by the object travelling, and if so, does this vary if you reduce or intensify the magnetic field? Also, what happens if the object is generating two opposing magnetic fields, would...

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. :)

Hello all It's been a while ,as I read the almost daily news on climate change , some question come up to my mind , dose the ionosphere has any effect on climate change , as we all know now the Earth magnetic field is weakening ,and the temperature is rising ,dose this two variables related to...

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 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...

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.

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]...

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...

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...

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!