Magnet Definition and 912 Threads

So I'm making a simulation to help me understand electromagnetics. Basically I have a stationary bar magnet, along with a moving electron. Each frame the electron has a force applied to it via the Lorentz force law, F = q(E+v cross B). Now E = 0, but how do I calculate B? The Biot-Savart...

Homework Statement I have a problem in my upper div. lab which uses a series of magnets to make a magnetic field. I need to explain the field in some way to show what we did mathmatically. The set up can basically be considered as a magnetic dipole with two mono poles due to insulators...

Hi. I'm doing an experiment and I'm kinda stuck. I know that a current produces a magnetic field. In this experiment there is a current carrying wire (copper) and a permanent magnet suspended above it. Deflection is being measured as the current is varied. I know that both magnetic...

Hello Everybody I heard about unlimited and free energy from magnet motors like perendev magnetic motor I believe that it work , Do I think true? I think perendev magnetic motor specification is: good Torque cheap GREEN Energy Easy to build My question is : " Why we don't use Magnet...

Does anyone know how to calculate the total energy of magnet? Thanks!

What would happen if you were two create something like in the photo. Lets just say that the magnets on the right are on the axle that's connected with motor. While the other magnets to right are on an axle. Would the magnets on the motor drive the other one?

If electricity possible to made only by using magnets (Lorence force) then how electricity was maded for creating with electromagnets the permanent magnets? Any history regards this? If magnets was taken from earth, then me bothering question how strong magnetic properties they have? And how...

Please help, if a magnet is displaced from its equilibrium position by a small angle (theta), show that it will oscillate with a period T given by T= 2*pi*sqrt(I/mB) I = moment of inertia of the bar magnet and equals M(L^2 + a^2)/12 B = Earth's horizontal component of magnetic field M is...

I know that accelerated charges give off electromagnetic radiation, but does an accelerated (spinning) magnet give off electromagnetic radiation as well? If so, what is the energy loss from the magnet's kinetic energy?

I've been trying to find the answer to a question i have online but haven't had much luck. Where did Stable or Pertinent magnets get their energy from? I've read plenty of people saying "magnets don't acquire or release energy" but that doesn't make sense to me. Let's use this scenario...

Hi, I am wondering what determines where these are on a magnetic object. For instance, on a sphere, why should there be a north pole and south pole at points rather than others. To make myself clearer, I am not asking why the south and north are opposite each other, but what determines those...

I was puzzling the Levitron today, and was trying to figure out what the magnets involved strength was, on the off chance that I may build a larger one for kicks. However, after some moderate googling, it doesn't seem like figuring out the strength of a magnet is a quick or 'easy' task...

Hi. I want to make an assembly in which when one clicks a switch, it lights an infrared LED for 1/30 of a second. Basically, instead of having a switch and a battery, i use a linear generator as a switch, giving current only when pressed to light LED. Like any linear generators, when one...

Homework Statement A permanent magnet synchronous generator (as used in the wind industry) develops 5MW of electricity at 12 RPM; What amount of mechanical torque would be required to turn this generator at 12 RPM.? These generators are said to be 95% efficient Homework Equations...

What makes a magnet, a magnet? Ok... I know about polarity and all that. I just don't get why certain elements and compounds aren't magnetic. For example, why isn't an apple magnetic? Thats a little extreme but I think you get the point :smile:

Homework Statement From Townsend "Modern Approach to Quantum Mechanics", problem 1.1: "Determine the field gradient of a 50-cm long Stern-Gerlach magnet that would produce a 1 mm separation at the detector between spin-up and spin-down silver atoms that are emitted from an oven at T=1500K...

Just a couple of simple questions. 1-Why does electricity kill? 2-What causes a magnet to be a magnet and certain things magnetic?

I know this may sound strange. Has anyone ever successfully created a working physical model of a magnet that exhibits the same properties ("flux" lines and attraction) without using magnetic materials or electrical influence? Thanks G

Do neodymium magnets polarized like this and with this same shape exist? http://upload.wikimedia.org/wikipedia/commons/d/d8/Bar_magnet.jpg

just wondering if its a sneaky answer or just as simple as put a magnet next to it?

Can you please tell me whether you think this magnet motor will work or not? If not then what is the reason why not. Most magnet motors seem to have a bad press, so I don't hold much hope for this one: http://www.flantoons.co.uk/magnet-motor001.jpg Thank you. Mike UK

Ok I have 2 questions about this. So I know that a current is induced when the magnetic field changes near the wire. So say I dropped the magnet North end up and South end down through this wire, the current would increase as it was nearing it, and decrease as it leaves it. 1) is this...

Greetings, The other day while working on my car I began thinking about solenoids and how they work, but I think I may have confused myself. It's been a while since I've studied magnetism, but I remember that the current through a wire loop, and thus a solenoid as well, is dependent on the...

I am trying to calculate how much forces is between two magnets, but the catch is they will be approaching each other at an angle. I have found plenty of information using the model of two magnets heading end to end, but am not sure if the formulas change when the magnets are not in that...

Hi all, I was wondering if anyone knew, or if anyone knows where I can find, the maximum magnetic field that a micro - electromagnet can put off... I am sure this depends on a lot, but I just need an estimation as I am running a simulation and need a typical value. I ran the simulation with...

I would like to know if anyone here has ever been involved in permanent magnet production, and more specifically, with the sintering process. What temperature must a NdFeB magnet be heated to for sintering and also, how do you determine the length of time you sinter for? What kind of density...

I am incorporating a solar chimney in my house build in Thailand, this will have a venturi to create the suction for removing warm air from the building and I intend to use this high air speed area to generate electricity. As air speed will be dependant on the Sun and not the more fickle wind...

What is the drag force on a magnet falling through a coil? I have found several sources online describing the drag force on a magnet falling through a conductive pipe. How might this vary if a coil is used in place of a pipe? Does the coil need to be connected to a circuit to create this force?

1. The problem statement, all given/known data A bar magnet is positioned at the mouth of a solenoid. The current indicated in the solenoid is then turned on. (Assume the solenoid is a lot bigger than the bar magnet.) Gravity and friction can be ignored. Describe what would happen, and...

Homework Statement "A light bulb is connected to a coil of wire. If a magnet is passed back and forth through the coil the bulb will light up. Why?"Homework Equations The Lenz Law isn't really an equation, but it states that: "The magnetic field of the induced current is in a direction to...

Hi, I am trying to design a simple water valve that opens a plug in a small water reservoir until its empty. So far I have a solenoid coil wound around a hollow core plastic pipe with a cylindrical rare Earth magnet inserted halfway into the pipe with a 'plug' attached to the top of the other...

Hi all Can you assist - I think that I am on the right track - but then I could be wrong.. Homework Statement Predict which direction the wire will move Homework Equations Right hand rule The Attempt at a Solution Current flows from positive to negative. Right hand...

Hello. I have problems with the Faraday and Lenz laws. Not problems with their definitions (they are OK), but with the usual assumptions and relation with conservation of energy: The definition of these two laws states: - Faraday law: The induced electromotive force or EMF in any closed...

I'm being asked to derive the equation for the magnetic field produced by a variable gap magnet. I've been given a few clues, but thus far have been unable to actually complete the derivation. The final equation should be: B_{ext}=\frac{mg}{lR}\left(\frac{d}{i}\right) I'm told I need to...

Maybe cut isn't the best word, but you get what I mean. Surely if all the negative polar molecules move to one side of the magnet and the positive polar molecules move to the other side, and you cut the magnet in the middle, you shouldn't get two more magnets? I'm still only doing high...

What happens, and why? (This isn't homework, just curiosity.) To be more precise, what would happen to the magnetic field of the magnet if we passed a current through it (assuming it is conductive). Will the current disrupt the magnetic domains? Will the magnetization disappear?

Let me first explain my situation here... I'm a math major and out of all the sciences, physics is my least favorite, but I have to take this science class that forces you to design your own experiments. Math is used in physics all the time, but I have a really hard time connecting math to...

Whether the magnetic field corotates with the magnet or not when a magnet rotates around its own magnetic axis is a problem which is known as unipolar induction and has been debated for a century. Someone thinks that the magnetic field can rotate together with the magnet, but the others don’t...

What is the answer? Should be B Please Explain the reason behind I don't understand how an induced Magnetic Field will cause the coil to move. (Not Homework)Source:tycphysics.org/TIPERs/TIPER%206_20_02_keys%20pdf/EMI%205a_Key_6_02.pdf thanks for helping

Homework Statement What is the magnitude of the normal force of the table on the lower magnet? (so there is a table with a magnet on top and below its surface) Homework Equations The Attempt at a Solution So i was wondering if someone could help me figure out all of the forces acting...

I have a question concerning magnets. Lets say i have 2 magnets each wieghing 1 gram each sitting on a scale. The scale reads 2 grams. What if i was able to stack the magnets by lining up the same poles so they repel each other and the magnet on top was floating over the magnet on the bottom...

I feel a little silly for posting this rather mundane question- but I really am at then end of my (limited) wits. I have an iPhone, and there is a rather strong magnet on my favorite purse (I believe it is a neodymium magnet, but don't know for sure). I have been researching this issue online...

http://www.geocities.com/sc_cannon/filxb.bmp A wire carrying a current I has a magnetic field from a permanent magnet crossing it at right angles. The force on the wire is equal to the cross product of Current Length with the Magnetic Field, B. What is the force experienced by the...

ur in a room with 2 iron bars one is a magnet and the other is not , they are the same shape and size , how do u tell which one is the magnet and all u have is the 2 bars to test this nothing else in the room.

I am working on a project, using magnets, and I am having trouble figuring out how to orient that magnets. I plan on lining a rotor and an armature with magnets. The magnets should repel off of each other and begin spinning, and before I hear this again, not that I don't appreciate you...

A moving electric charge (moving relative to another object) will create a magnetic field around it. So if this charge moves passed a permanent magnet, their fields will interact and cause a force (basic principle of the motor effect). However, if the electric charge is standing still in...

I posted this in general math, but then I saw that calculus and analysis was a more appropriate place for it. I am looking for a solution to this problem: When a magnet is dropped from rest near an iron wall, it accelerates downward due to gravity at constant acceleration. It also...

When a magnet is dropped from rest near an iron wall, it accelerates downward due to gravity at constant acceleration. It also accelerates toward the wall, and the closer it gets to the wall, the greater the acceleration. Can anyone refer me to a solution that would give the position of the...

When we magnetize a ferromagnetic material, we provide an input of energy. Is it possible to demagnetize a magnet, and convert a fraction of the energy to usable work? (Of course, this is not a useful way to generate work, and some fraction of the input energy is lost)

Is it possible, thematically or practically, to construct a hollow spherical magnet with inner surface and external surface of opposite polarity? How would the magnetic field looks like? Assuming it is possible, what would happened if I place a smaller hollow spherical magnet, but of the...