Magnetism Definition and 974 Threads

Hello: Many many years ago I walked away from community college with an associates degree in physics, and despite my fondness for the subject, I had to put it aside for other things. I recently happened upon something that lead me to realize how much I had forgotten, and so I've decided to...

Homework Statement http://ploader.net/files/795e05b46860aa55fc17ce371c14eb99.PNG The Attempt at a Solution http://ploader.net/files/574a81d69c34f39fd049610251d0f0bd.GIF Ok so I got the first part of the question. The problem that I am having is the direction of the field lines, which...

Yes, yes I know about the template, but these questions are so basic that I don't really know what I can show as work... Sometimes all I need for help is the relevant equation itself -.- So please don't delete or hate. Thanks! 2. http://tinyimage.net/images/50136173150204648365.png The...

Homework Statement A force acts on a rectangular loop of wire, pulling it out of a magnetic field. Calculate the force required to pull the loop to the right at a constant speed of 4.42 m/s. B = 0.44 T l = 0.350 m v = 4.42 m/s R = 0.356 ohms Homework Equations Fmagnetic=I*l*B...

\langle\hat{S}^z\rangle=\hbar\frac{(S-P_S)(1+P_S)^{2S+1}+(1+S+P_S)P_S^{2S+1}}{(1+P_S)^{2S+1}-P_S^{2S+1}} Can you tell me something more about Callen result? And this function P_S? In book Nolting "Quantum theory of magnetism" this relation is get from diferential equation...

Homework Statement What is the Kinetic Energy of an electron that passes undeviated through perpendicular electric and magnetic fields if E = 4.0 kV/m and B = 8.0 mT? m_{e} = 9.1 \times 10^{-31} \textup{kg} q_{e} = 1.6 \times 10^{-19} \textup{C} Homework Equations I got stuck doing...

Hello everybody Basically as the topic states: How can you calculate "The spatial wavelength of a Halbach array" (symbol lambda)? Context: The reason I ask is that since I've got bored during my easter holidays I decided to try a wee science project and try and make a model of an...

I'm stumped on a problem about Gauss' Law for Magnetism because I don't know what "local form" is. From context, I suspect that local form refers to the expression of an equation with the del operator (i.e. del x E = (charge density/(E0)), but I'm not sure. I've been self-teaching with Tipler...

Homework Statement Heres the problem: Homework Equations F=BIL F=qvB The Attempt at a Solution I really don't know where to start. Can you guys give me a hand. Maybe a link to a web page explaining. I understand if it were convention current flowing through the 'pipe' it would experience a...

Homework Statement Iron is a metal that exhibits magnetic properties, but most pieces of iron are not magnetic. Why? Homework Equations none The Attempt at a Solution I have no idea. I am very confused.

If two attracted magnets are placed on a balance and weighed, would they weigh less if they were set to repel?

Quick question, that seems pretty obvious, but I wanted to check. Magnetic fields follow the rules of super-position similar to the way electric fields do, correct?

Here's what I don't understand. Start with two charges e1 and e2 on the plane of this screen, that are Y vector apart. e1 is moving at velocity V1 toward the top of the screen. e2, directly to the left, is moving at velocity V2 toward the right...

It would be appreciated if formulas that would directly or indirectly allow the following quantities in question to be calculated are posted in this thread. The questions are listed below: 1.) How strong would a magnetic field have to be to block a given amount of electric power in a given...

When discussing magnetism or magnetic systems, Do you apply an H-field? or apply a B-field? I suppose this is in the general situation where you apply a magnetic field to a material. In relation to B-H loop showing hysteresis, I notice that the "x-axis", typically dependent variable, is...

E & M Magnetism Relativity "Paradox" :confused:In theory the laws of magnetism are derivable from coulomb's law and special relativity. Right. While my physics homework group were doing a problem set, I came up with this seeming paradox. (This isn't a homework question). There are 2 senarios...

I have a bunch of conceptual questions on Earth's magnetism. The problem is I have not understood the elements there. I am not able to visualize the magnetic field ,horizontal component,declination,inclination. I don't know the directions of them too. My book hasn't given pictures of them...

What can reflect,block or neutralize magnetism and magnetic field of a magnet?

how or from where the magnetic force is coming? why some metals are magnetic?

Homework Statement An electron is moving in a uniform magnetic field of 0.25 T; its velocity components parallel and perpendicular to the field are both equal to 3.1*10^6 m/s a) What is the radius of the electron's spiral path? b) How far does it move along the field direction in the time it...

If I cut a magnet exactly where the border of its south and north pole is...does it mean I'm creating a one-sided magnet? Also, are one sided magnets naturally-occurring?

How much E&M is involved in a MechE degree? I'm a high school senior in AP Physics C: E&M and I hate it with a passion. I loved Mechanics, but E&M is terrible. Would I just need to take the one required class (Physics 2), or do I need to use multiple E&M concepts throughout undergrad? I am...

hi, Is it fair to say that magnetism rises from the fact that there are more up than down electrons or they also have to be at the Fermi level? I am a little bit confused about this Fermi level thing. I heard people saying that up/down electrons difference must be at the fermi level. Also...

I apologize, I wrote all of this out in a word processor before attempting to post it and I did not notice that there is a template for giving problems. I hope you forgive me, my posts tend to be wordy and take awhile to write; attempting to write it in the text box would result in the server...

i was wondering if it is possible that there is no such thing as gravity? i find the mysteries of coral castle , giza pyramid and stonehenge and such as astounding i don't know how true the claims are about the ancient people knowing how to do "anti-gravity" but apparently they thought...

Homework Statement The lines show the equipotential contours in the plane of three point charges, Q1, Q2, and Q3. The values of the potentials are in kV as indicated for the +5, 0, and -5 kV contours. The positions of the charges are indicated by the dots...

I would really appreciate any help understanding magnetism. First off, for all I know, no one can fully explain WHY moving charges create a magnetic field, but can tell you HOW they will behave and interact with each other. I'm hoping I'm wrong and that there is a reason...

1. How is magnetism propagated? The descriptions I have read of magnetism explain about spinning electrons and the effects of magnetic fields, but I can find no explanation how magnetic force is propagated. Gravity is explained via GR and the effects of mass/energy on space-time, but I don't...

Homework Statement The potential caused by an array of charges in a region of space can be described by the equation V(x,y,z)=2x+xy+y2-xz2 volts, where all distances are measured in metres. If a charge of 2 mC is moved from the position r1=(1,2,0)m to r2=(3,1,0), calculate the resulting change...

Anyone know of any good papers, research i can view on magnetism, also any equations for working out the force of one etc would be fantastic.

Does anyone know where I can purchase the hardcover 1985 Electricity and Magnetism? Some schools, such as Caltech and MIT, still use the book; however, Caltech does not have it in their online bookstore and MIT lists an 09 edition (which I assume is an ebook?). Some copies are floating...

Homework Statement 2 parallel long, straight conductors lie on a smooth plane surface. 2 other parallel conductors rest on them at right angles so as to form a square of side 'a' initially. A uniform magnetic field B exists at right angles to the plane containing the conductors. Now they start...

When current (DC) passed through a wire it creates a magnetic field around it, right? But if you placed magnets around that wire would they interact with the electricity flowing through the wire? If so, to what extent?

I'm taking E&M next semester, and the book we use is quite good at explaining concepts, but it only has 9-12 questions per chapter. I would like to do more practice problems. We used the same book for modern mechanics (it is a two-edition set, the first is mech and the second is E&M). Any...

hi ... i want to ask about domain theory of ferromagnetism... first of all , According to classical electromagnetism, two nearby magnetic dipoles will tend to align in opposite directions, so their magnetic fields will oppose one another and cancel out. how does this happen? after this ...

? I'm just curious. Also I'm having trouble with mechanics. I feel like i have no idea how to grasp fnet and calculating it. I also REALLY REALLY REALLY suck at drawing free body diagram. Math is a walk compared to physics which feels like a marathon. I'm actually not that great with math but...

A couple weeks ago, a friend tossed out 'what's the magnetic field of the Earth look like?' It's not the same I learned it was when I was in school. We have great studies to prove it's shape and characteristics. And then I began to wonder what else has been found out about this. I found the...

Is gravitational acceleration, g, at any given spot around the globe imparting sufficient velocity so that the interaction (interchangeable) between a ferromagnetic coil and a magnetic field may generate electricity?

¿How do modern physicists think about magnetism? Recently, I realized something really cool that made me re-evaluate the way I thought about magnetism. I'm not a physicist, I'm in the early process of becoming one (old cow trying out a whole new career). I had this "fieldy" notion about what...

In magnetism does a photon (or stream of) spin around a particle to create magnetic force? Or to ask this another way, are photons force carriers in such a way that since they spin around a particle so fast, their paths have become effectively a barrier, hence the force.

I'm taking gen. physics 2, which consists of electric fields, magnetism, stuff like that. Big difference from classical mechanics in physics 1. I remember in calc III, I learned nothing from my professor because he didn't know how to teach. I basically learned the entire course from Paul's...

What is the difference between static attraction or repelling, compared to magnetic. I understand the princips of static build up and why a charged positive and charged negative attract each other. I also understand how the atoms are arranged in a "metal-magnet". But why can't you attract a...

what would a magnetic field look like in 4+1D? In 3+1D the field lines simply rotate around the axis which points along the direction of motion of the electron. But in 4+1D this is not defined. But if magnetism is simply a result of relativity then there should be a way to make the equations...

Several years ago Tethered experiment demonstrated that current can be produced by a long wire moving in Earh orbit, due to Earth magnetism. Being Earth inside Sun magnetosphere, wouldn't it be possibile to accomplish same task in a long wire properly positioned on Earth surface? Possibly at...

Hi guys, I was answering some questions on my physics homework and I didn't understand why the answer was what it was... the first question was this: 1.) A hollow uncharged metal ball hangs from a silk thread. A glass rod has been charged by rubbing with rayon. When it is brought close to...

Hello, Been trying for more than a while to understand the idea of Diamagnetism and can't seem to grasp it (not that surprising since i know nothing of physics). If gravity and magnetism are two completely different forces which cases different reactions and are cased by different things...

Radiomagnetism or radioactive magnetism. Has any research been done on this phenomenon as a source of propulsion. Are we thinking too small? Can the various levels of radioactivity affect magnetic propulsion by increasing its magnitude. What would be required to observe this on a large scale...

Here are a few more questions on Magnetism. 1. I now know that Electricity is discharged when there is a "Potential Difference", but how does this charge come into place, how does it form. This is one of the times I am asking for you to be as specific as you can (remember, I am 13 here...

Some magnetism and Electricity questions. Remember, I am only 13, so don't answer me like your are talking to a Major in Physics, but please answer me with detail, as if you were talking to some one in high school, I want to understand the details of things, not the general idea. Question...

Sorry for the un-informative question, but I am new here and am only 13 years of age. What causes magnetism, and why is it that only certail substances can be Magnetized, and others cannot.