Magnetic Definition and 1000 Threads

If the speed of light is ~300 m/s in a vacuum, can the electric and magnetic fields of the wave be condensed such that it travels faster? The idea being that an outside force condenses these fields and lenghtens the wavelenght with no loss of energy thus increasing the directional speed. The...

I don't know if this is the right place to put this, but I am very lost as of right now. I am doing my 11th grade physics project on magnetic levitation. From what I can understand, there are 2 "main" types of magnetic levitation, them being with superconductors and with electromagnets. For the...

Homework Statement Here is a link to the problem: https://imgur.com/a/0T9sF I am having trouble finding the time it takes the loop to leave the field in part a. Homework Equations ## emf=-\frac{d \Phi}{dt} ## ## \Sigma F=ma=mg-BIl ## ## \frac{dv}{dt}-\gamma v=g ## where ##...

Hi everyone, Lately I have been studying the Poynting Flux and I am familiar with the classic examples of how it can be used to describe the power being dissipated by a resistor and the energy flowing into a capacitor, but I have never come across a similar analog for how the Poynting flux...

Homework Statement A certain magnetic system contains n independent molecules per unit volume, each of which has four energy levels given by 0, ##Δ-gμ_B B##, ##\Delta##, ##\Delta +gμ_B B##. Write down the partition function, compute Helmholtz function and hence compute the magnetization ##M##...

The spin magnetic moment of a charged, spin-1/2 particle is $$g \frac e {2m} \frac \hbar 2$$ where g is the g-factor (2 for any particle in tree-level approximation, 2.00231930436182 for electron), e is charge m is mass ##\frac \hbar 2## is spin But with zero mass this expression does not make...

Homework Statement A force of 2.4N is exerted on a -1.8µC charge in a downward direction. What is the magnitude and direction of the magnetic field at this point? (The assignment sheet is called "Electrostatics Questions", hence the "Electrostatics?" in the title) Homework Equations Electric...

What is the difference between the Magnetic Field Lines of the Dipole and Circular Current Carrying Wire at the centre?

Homework Statement Two particles having mass m separated by a distance d is uniform magnetic field as shown in the figure . If v=qBd/m, at what instant does collision occur. The coulomb force between the particles is switched off. Homework Equations T=2πm/qB The Attempt at a Solution For the...

Homework Statement A current I flows along the surface of a hollow conducting cylinder. The radius of the cylinder section is r. By using Ampere's law, show that the magnetic field B outside the cylinder is B=\frac{\mu_0}{2 \pi} \frac{I}{r} Homework Equations Ampere's law...

Homework Statement A thick slab in the region 0 \leq z \leq a , and infinite in xy plane carries a current density \vec{J} = Jz\hat{x} . Find the magnetic field as a function of z, both inside and outside the slab. Homework Equations Ampere's Law: \oint \vec{B} \cdot d\vec{l} = \mu_0...

Hi, i'm finishing my final degree project, it's about a new type of pallet conveyor dragged by magnets. I know for a fact that magentic force is inversely proportional to the distance squared, and I've designed and built my prototype with that in mind. Now I'm writing my final report and i need...

School physics has always taught us that the big difference between a magnetised object and an electrostatically charged object is that the latter has on it an isolated positive or negative charge whereas the former cannot be an isolated N or S pole, ie. you cannot have a magnetic monopole on a...

If an AA battery were placed in some kind of ideal conducting 'ether': 1) Would current flow, and if so, what would the flow of electrons look like? 2) How would the magnetic field look? (I imagine that if there was an electric current flowing, that the magnetic field would look a little like...

Homework Statement If you were to gain a few electrons and go running in Vancouver, what would be the magnitude and direction of the magnetic force that you would experience? Homework EquationsThe Attempt at a Solution So I was able to determine the magnetic force but my only problem is...

Hi guys, Non engineer here trying to understand an engineering principle. I think I must be going wrong somewhere in my thought process. 1. Faraday tells us that the EMF generated in the secondary of a transformer is equal to the change in magnetic flux divided by the change in time. 2. The...

Homework Statement A single electron atom has the outer electron in a 4f1 excited state. Write down the orbital and spin angular momentum quantum numbers and the associated magnetic quantum numbers for this state. Homework Equations I don't think there is any relevant equations. I think it...

[Mod Note: Thread moved from Classical Physics, hence no formatting template] So today we performed an experiment to measure the Earth's magnetic field in three dimensions. For one of the dimensions we got 6.6x10^-5 i We were wondering if an imaginary magnetic field was possible and what it...

From wikipedia: "An electromagnetic wave such as light consists of a coupled oscillating electric field and magnetic field which are always perpendicular; by convention, the "polarization" of electromagnetic waves refers to the direction of the electric field." A polarizer is an object that...

So long story short, I'm trying to write a scientifically accurate short story/animation thing and it revolves around a mass driver: it's a giant and deep hole on Mars with a magnet on the bottom or sides or something and fires packets of objects to Earth at breathtaking speeds (4.66 million...

Homework Statement [/B] Consider the hydrogen atom in the 42F5/2 state. Take into account the effects of finestructure (spin-orbit coupling). (a) Write down the spectroscopic notation of the state that the 42F5/2 is degenerate with, in the absence of an external magnetic field. (b) Calculate...

I was just in a conversation with someone regarding the magnetic field resulting outside of a solid cylinder, with a current moving down the center of the cylinder, and then the resulting magnetic field after removing the current. Now I haven't thought about magnetic fields/magnets for a while...

Hello. I am reading a paper which says that only Earth (between the rocky planets) keep a strong magnetic field and it arose an question on this: Why does the magnetic field of the planets decrease with time in such planets? Why the magnetic field of the Earth is the only one which keeps strong?

I would like to fine the kinetic energy of a cone that rotates around its symmetry axis. I consider that the cone is formes by infinite cylinders with different radius and infinitesimal height. I end up with this result: K=1/4w^2R^2hM where w is the angular velocity R the radius h the height and...

As we know, work done by an outside agency in creating some current ''I" in an inductor 'L' is 1/2LI2. Now this result is derived by quasistatic approximation if I am not wrong. Now, I am assuming that in non quasistatic (real) scenarios, the work done by outside agency would be different(If you...

The sources I've looked at claim the magnetic field is present because there are still some electrons in the neutron star. Here is how I understand their reasoning: a star's radius significantly decreases when it collapses into a neutron star, ultimately decreasing its moment of inertia. In...

Homework Statement An infinitely long cylinder of radius R carries a "frozen-in" magnetization, parallel to the axis, ## \vec M = ks \hat z ##. There are no free currents. Find the magnetic field inside and outside the cylinder by two different methods: (a) Locate all the bound currents and...

Homework Statement Calculate the force of magnetic attraction between the northern and southern hemispheres of a uniformly charged spinning spherical shell, with radius R, angular velocity ω and surface charge density σ. Homework Equations Maxwell Tensor : Tm = [/B](1/μ) * ((B*n)B -...

How would you calculate the induced magnetic field B at some distance R from a bar magnet, given the magnetic moment of a magnet? (In general)

For the Image given, i have to calculate reluctances of air gap and core which depends on respective mean path lengths. For the left hand core, the mean path length calculated in the solution manual is 1.11 meter . However what I don't understand is that why is the length of the air gap included...

If you have uniform magnetic field, would something like a halbach array which has a non symmetrical magnetic field experience a net force? If not, is there any way to shield one side of a magnet so that it would experience a net force? On a similar note, if you wound a wire around a sphere in...

I am putting together a hands on activity for ninth graders, which will include testing different materials to determine whether they are attracted to a magnet. I have collected fasteners (screws, nails, bolts), and surprised that the fasteners I purchased labeled "zinc" are attracted to the...

Homework Statement A metal rod of mass M and length L is pivoted about a hinge at point O as shown in Figure P32.80 (I have attached this to this post) The axis of rotation passes through O into the page. Find the ratio of the maximum electric field inside the rod to the applied magnetic field...

Homework Statement [/B] A short current element dl⃗ = (0.500 mm)j^ carries a current of 5.20 A in the same direction as dl⃗ . Point P is located at r⃗ = ( -0.730 m)i^+ (0.390m)k^. Find the magnetic field at P produced by this current. So basically what they are asking me for is the x, y, and...

Homework Statement The Hamiltonian of a spin 1/2 particle is given by: $$H=g\overrightarrow { S }\cdot \overrightarrow { B } $$ where ##\overrightarrow { S }=\hbar \overrightarrow{\sigma }/2## is the spin operator and ##\overrightarrow { B }## is an external magnetic field. 1. Determine...

Homework Statement Homework EquationsThe Attempt at a Solution Velocity of particle at any time t is v = vxi + vyj Net Force on the particle F = (2qvyB)i + (2qvxB)j Net acceleration of the particle = F/m Magnitude of net acceleration = (2qvB)/m Particle has an initial velocity as well...

In a solenoid of N loops and uniform magnetic field B, the magnetic flux is B*N*A, where A represents the area surrounded by each loop. I see that the N comes from the fact that you have one A for each turn, and you have N turns, so the total "area" is NA, but why do we use this? Why isn't...

My physics teacher said that the northern lights are the product of charged particles coming from the sun and interactign with our atmosphere. I believe he said that these are deflected by Earth's magnetic field and directed towards the North and South poles. When I look at pictures on this...

Homework Statement Homework EquationsThe Attempt at a Solution As soon as switch S is closed , a current would flow in the circuit and the capacitor would act like a conducting wire . Force F =ilB towards right will act on the slider . There will be an acceleration but the velocity of the...

Any pure state of spin-1/2 particle can be represented by a superposition of spin up and spin-down relative to an arbitrarily direction. lw>=a l+> + b l-> where a^2+b^2=1 If there is no magnetic field, the measurement of the spin is random and we get 50-50 chance to be spin up and spin down...

Homework Statement Find the exact magnetic field a distance z above the center of a square loop of side w, carrying a current I. Verify that it reduces to the field of a dipole, with the appropriate dipole moment, when z >> w. Homework Equations (1) dB = μ0I/4πr2 dl × rhat (2) r =...

Homework Statement Homework EquationsThe Attempt at a Solution Hi! I got the magnitude using F=qvB using information from the top of the qs. But the direction is confusing me. I used the Fleming's left hand rule but it sort of isn't giving me the right answer

Homework Statement Homework Equations The right hand curl rule gave me the counterclockwise direction for the magnetic field but I am confused about how is it going to work for the particle. Thanks The Attempt at a Solution

Homework Statement Hi! A long, straight, current-carrying wire is placed between a pair of magnets as shown. What is the direction of the force on the wire? Homework Equations Fleming's hand rules The Attempt at a Solution I used the Flemings right hand rule but that gives me that the force...

Hello, I have a doubt about the Complete Set of commuting observables (CSCO) in the cases when there are a magnetic field ##B## in z. The statement is find the constant of motion and CSCO for a particle of mass m and spin 1/2, not necessary a electron or any atomic particle. I know that the...

Homework Statement Homework EquationsThe Attempt at a Solution In this problem as the rod moves towards right, magnetic force of magnitude ilB starts acting towards left on the rod.This decreases the speed of the rod .The EMF induced in the rod is Blv where v is the instantaneous speed of...

I'm reading about the theory behind MRI, specifically from Farr's Physics for Medical Imaging, 2nd Edition, by Allisy-Roberts and Williams. According to this book, the spins of the free protons in a sample line up, either parallel or antiparallel, with the externally applied magnetic field. In...

Homework Statement https://imgur.com/gallery/vCOZq Its question 26, and the figure can be seen at figure 30.26 Derive and expression for the magnetic field produced at point P due to the current carrying wire shown in figure 30.26. The curved parts of the wire are pieces of concentric...

Homework Statement A wire 1.0 mm in diameter carries 5.0 A distributed uniformly over its cross section. a) Find the field strength 0.10 mm from its axis. b) Find the field strength at the wire’s surface Homework EquationsThe Attempt at a Solution I've used the Biot-Savart Law for a wire for...

Homework Statement (a) What voltage will accelerate electrons to a speed of ##6.00 \times 10^{-7} m/s## ? (b) Find the radius of curvature of the path of a proton accelerated through this potential in a 0.500-T field and compare this with the radius of curvature of an electron accelerated...