Magnetism Definition and 952 Threads

1. I would like to test myself on how well I know my information about certain metals, some of them get me a bit puzzled. How would you rate the electrical conductivity of cast iron? Poor, good, excellent or best? Also the thermal conductivity of 304 stainless steel? Poor, good, excellent or...

I would like to test myself on how well I know my information about certain metals, some of them get me a bit puzzled. How would you rate the electrical conductivity of cast iron? Poor, good, excellent or best? Also the thermal conductivity of 304 stainless steel? Poor, good, excellent...

Thirty years after learning E&M from the wonderful book by Purcell, I noticed that the copyright page of my dog-eared copy of the 1965 edition includes a notice stating that it is available for use by authors and publishers on a royalty-free basis after 1970. The book has gone through two more...

I am a computer science major and we are required to take two semesters of physics. First semester is based on mechanics and the second semester is focused on electricity and magnetism. I was wondering how these topics are used in computer science and in what specific area? I have tried looking...

Homework Statement in the topic related to magnetic dipole moment. The result is derived that m/l = q/2M m= Magnetic Dipole moment of the substance[of mass M whose angular momenta=L] with a charge q Homework Equations Now my question to you is whether this "result"...

Homework Statement A force eld E has the spherical components Er = (2Dcosθ)/r3 Eθ = (Dsinθ)/r3 E\phi = 0: (a) Evaluate by line integration the work it does in taking a point (parti- cle) from point A in the diagram to point B via the quarter circle r = a; 0 <...

If we have a solenoid and a magnetic passes through it , it will produce a dc voltage in the wire . If we want to calculate the power , we find out the current using ohms law then we use P=VI . I know there is power loss due to the resistance ( joule effect) . But what about the opposing...

So I'm a physics major in my second semester of undergrad physics and have been completely blown away by electricity and magnetism. The stuff just amazes me. So I was wondering what the current hot topics of E&M are. What are the unanswered questions? What kind of things would I be...

Consider a wire with charges moving with speed 'v'and '-v' in frame F (with charge q at distance s away moving at speed u). In frame F', the charge q is stationary, and so the speeds of the charges in the wire are v+ and v-, where v- > v+ Hi guys, I have trouble following through the proof in...

Hello, I have started reading a beginners book (from the "stop faking it" series) on electricity and magnetism. Its supplied with funny little experiments to help me understand the topic. But I have trouble understanding the intimate relationship between electricity and magnetism. I believe I...

Whenever people begin to explain the nuclear strong force, they relate it to electricity. I was wondering if color charges, besides also interacting with one another in a way that's analogous to electricity, can also interact in a way that's analogous to magnetism. I have asked some professors...

Homework Statement In the ATTACHMENT is the given circuit. Which contains two resistance R1 and R2 in form of circle of radius r = 1 m with a battery having e.m.f. V = 10∏ volt. Upper resistance is having resistivity = 4Ω-m & lower resistance having resistivity = 2Ω-m. Angle between two...

My answer key claims it's answer E. I don't think it's right; I think it's cobalt with three unpaired electrons. Not four. A 3d7 configuration, through the Aufbau principle, would fill two of the five d electron pairs completely and leave three half filled. This works mean it's also para...

hey everyone, I have a questions, that is very general, and perhaps, silly... but why are coils so significant in terms of electricity and magnetic fields? why is it when you push a magnet through a coil, you get a charge, but not when you touch it to a straight copper pipe? Or when you see...

Homework Statement 1). Magnetic Field lines begin and end at magnetic charges. (True or False) 2). Magnetic field lines are "lines of force" for charged particles. (For example, a charge will follow the magnetic field lines.) Homework Equations The Attempt at a Solution I...

Hi, inductance is the property of a conductor by which a change in current in the conductor "induces" (creates) a voltage (electromotive force) in both the conductor itself (self-inductance). --wikipedia From what I understand, the inducing happens due to the resulting change in magnetic field...

If i put something from space to Earth it accelerates at a rate of 9.8m/s2, why is it so? Does acceleration happens in attraction between two magnetic poles? If so what is its rate?

i am very confused by the idea of magnets how do magnets attract things ? and if they do attract things , then what is the importance of flux lines ? i mean , shouldn't magnets just align things to the flux lines in the direction of the north pole ? i want to know how magnets work in...

If, -There is an iron rod.(It does not have magnetic potential energy at this time) -I made an electromagnet in a far away place. -When I bring the magnet closer to the iron rod,the iron rod suddenly gets kinetic energy.Why? As energy cannot be created,from where does the kinetic energy...

Can someone recommend a physics book on electricity and magnetism? The book that I just finished reading for my class was https://www.amazon.com/dp/0971313458/?tag=pfamazon01-20 The book above hardley mentioned vectors and I am looking for a book that explains all the concepts in terms of...

Hi, I am 15 and I got interested in this question. My question is not how magnetism exists, it is WHY magnetism exists? Thanks

I'm studying magnetism from my textbook, and I have several doubts. 1. Magnetic flux in my textbook is defined as the number of magnetic field lines passing through a surface held perpendicular to the lines. However, the unit given is Weber- N.m/A How do 'no. of magnetic field lines' connect...

I am a little confused about the Mermin-Wagner theorem, and the assumptions it makes, and I would like to better understand the 'exceptions' to the rule that occur in practical (non-ideal) scenarios. As is my understanding, The Mermin-Wagner theorem states that there cannot be spontaneous...

Homework Statement Please see attachments. Homework Equations F=ILB The Attempt at a Solution F1 - F2 = FT = 5*10^-5 Second one no clue.

In basic but precise terms, can someone please explain to me the fundamentals on how/why these things operate? I've been reading about how these things work but I really want a good understanding on why these works too. Thanks :)

Natural Magnets: How do they work? I'd prefer a technical answer on a subatomic level. Electromagnets: Say you have a copper wire hooked up to a negative terminal and on the other end of the wire a positive terminal. Due to a potential difference, electrons flow from the negative to the...

If a prerequisite for E&M is Multivariable calculus, why is it offered in high school (without that pre-req)? Is the High School E&M equivalent to physics 2 in college, and if that is so, Physics 2 is still offered before Multivariate calculus. Can someone clear this up for me. Am I getting two...

Homework Statement A square loop of wire of side length L lies in the xy-plane, with its center at the origin and its sides parallel to the x- and y- axes. It carries a current i, in a counterclockwise direction, as viewed looking down the z-axis from the positive direction. The loop is in...

I'm sorry if I may be asking an unanswerable question here, but I've looked all through the forums and the internet to find a satisfying answer to why moving electric charges create a magnetic field. I'm not trying to ask why electrical attraction/repulsion exists, as I take that as a...

1 - How does an electron's spin generate its own magnetic field? 2 - Why are only the orientations of electrons taken into account in statements such as "permanent magnets are created when the orientations of the spin of the electrons are orientated in the same direction" when protons also have...

Magnetic effects on the brain are well known, as are magnetic brain scans, but I'm having difficulty finding anything to say magnetism has a function within the brain. I can find electrical communication, but not magnetic. Am I missing something ? Folk, do say if so.

So I am taking Physics II this fall semester. I am an engineering major, and I am currently split between mechanical, and civil. My questions is how hard will the class be for me? I have already done the three semesters of calculus including a vector calculus extension. I got an A in calc III...

Hey yall: So I ran across this confusing question and was wondering if you guys could help me out. Consider the fact that you have a positive particle (which would be q=1.6E-19) that is traveling at 1.9E4 m/s perpendicular to a 1.0 x 10-3 T magnetic field. If the radius is .40m what is the...

I've been introduced to ligand-field theory lately and was then wondering what roles f orbitals play in the magnetic properties of elements and alloys. Apparently f orbitals behave oddly in that they hybridize in weird ways because they're so large and that the crystal field actually affects the...

Homework Statement The figure shows the path of a positive ion moving in the xy plane. There is a uniform magnetic field of 6000 gauss in the z direction. Each period of the ion's cycloidal motion is completed in 1 microsecond. What is the magnitude and the direction of the electric field that...

Homework Statement http://upload.lsforum.net/users/public/c7843Untitleda235.jpg when the switch is closed what happen to the golden ring when the switch is closed? explain the switch remains closed. what happen to the ring if the slide contact of the rheostat i) is kept at A ii) moves from A...

Magnetism of a bar magnet -- maximum rate of change? If a bar magnet is placed along the x-axis with (0,0) at its center, along which axis does the magnetic field fall off faster and why?

Homework Statement 1. Determine the magnetic force acting on an proton (m = 1.67 x 10-27 kg) moving at 2.9 x 106 m/s in a magnetic field of 6.8 T. The proton is moving south. The magnetic field points straight down. 2. A 6.0 m long wire with 7.0A of current flowing through it experiences a...

The path of electrons emerging grom an accelerator must be bent by 90° by a 'bending magnet' so as not to strike a barrier in their path a distance d from their exit hole in the accelerator. Show that the field B in de bending magnet, which we assume is uniform and can extend over an area d*d...

I was reading here https://www.physicsforums.com/library.php?do=view_item&itemid=294 gauss law's for magnetism says ∮B⋅dA = 0 but then faraday's law has d/dt ∮B⋅dA in it. Well if its 0 then d/dt of 0 is 0.

Homework Statement Question: An electron is located on the Earth's magnetic equator at an altitude of 1000m. In which diretion will it be deflected when it is projeted upward? Homework Equations Not sure The Attempt at a Solution I'm trying to study for an electromagnetism exam trying...

Maybe a stupid question, but I'm trying to get my brain around the concept of magnetism, specifically for static magnets, not electromagnets. I understand that the magnetic field is a result of all the moments in the atoms being aligned. The spin of the electrons around the atoms is the current...

https://www.dropbox.com/s/gvml20bk7435zoa/a.gif I need to calculate the equivalent capacitance of this circuit, but I cannot tell which of the capacitors are in series or in parallel. Can someone explain to me how can we figure this out?

Homework Statement An ion of mass m and charge q is accelerated from rest through a voltage of ΔV. It then enters a magnetic field. Determine the mass of the ion in terms of the measurable quantities: q, ΔV, (B^→) , and x. Homework Equations The Attempt at a Solution m =...

Do any celestial bodies not have magnetic fields? Why? I'm having a difficult time finding good resources for dynamo theory a question about that... So first what I know: 1 - The Sun has a nonmetal hydrogen/helium plasma interior which is generating a magnetic field 2 - the Earth has a...

Do any celestial bodies not have magnetic fields? Why? I'm having a difficult time finding good resources for dynamo theory a question about that... So first what I know: 1 - The Sun has a nonmetal hydrogen/helium plasma interior which is generating a magnetic field 2 - the Earth has a...

This may seem really elementary or just based on total misconception but can you not explain any pulling force at distances in terms of relative space and time coordinates instead? Gravity before Einstein: property intrinsic to mass; masses pull each other. ...after Einstein: property...

Hello there! I have a question regarding the behavior of test particles inside a slowly rotating thin spherical shell of matter under the influence of the gravito - magnetic "lorentz force" (this is all in the weak field slow motion approximation). I want to see just how analogous I can claim...

My physics sucks but does gravity affect electical charges inside devices... Does it affect magnetism in coils... I thought it has an affect on anything regardless of how small it is.. right?

Hello all. I was wondering if anyone know of a website where I can learn more about magnetism? Nothing in particular, I just wanted to know as much as I can on the topic. I have a huge interest in this topic and hate spending so much time looking online only to find bits and pieces. Please...