Magnets Definition and 562 Threads

Firstly, please note that I am talking about the period BEFORE electricity and magnetism were unified. So I am NOT seeking for answers based on Ampere atomic current model of magnets. I have read the following statement about the property of magnets at two different places. One from here: and...

When two magnets already sticked to each other being pulled apart, energy is applied, so I assume that the energy is stored like some sort of potential energy which will be turned back into kinetic energy when they accelerate towards each other to stick back together. So the magnet itself...

I have been experimenting with solenoids used to excite steel guitar strings electromagnetically. These can be found in a variety of infinite "sustainer" products such as the ebow. They generally consist of a pickup, an amplifier and a solenoid which form a simple electromagnetic feedback loop...

I was torn between Materials, Mechanical and Electrical Engineering but could not think which would be the best home for this question so I’ve put it here for now. I tore open an old exorcise bike that used a big fly wheel with magnets on a lever and a strip of copper around the rim. I could...

Hi All, My daughter did a science experiment on homopolar motors. The only variable was the number of magnets on each motor. We found out through the experiment that the more magnets we attached to the motor, the longer it spun before the battery died. I'm assuming it has to do with the...

I know that magnets produce magnetic fields (due to internal currents within the magnet). I also know that magnetic fields cannot do work on particles. Given that, here is an apparent paradox I cannot fully understand: Consider a strong magnet and let us imagine bringing a small iron object...

Hi, i have a question. I need to know how much Newton it takes to separate 2 magnets or a magnet from a from a piece of metal. I've bought a spring scale that measures max 50 gram, so very accurate. Now what if i attach the scale to the magnet and i pull it horizontally just enough to...

Im a bit of a physics newb so bare with me. I am designing a product that uses rare Earth magnets as a mounting solution for radar detectors and wanted to know if these magnets would somehow interfere with the performance of the radar detector? The magnets will not be mounted to the detector...

Can 2 bar magnets be stuck together to create a magnetic field about twice as strong?

I am currently working on my high school's upcoming production of Beauty and the Beast. In the musical, there is a rose which loses petals at specific moments in the script that represent the castle's inhabitants slowly becoming less human. I figured that one of the best ways to do this remotely...

The picture below shows an image of a bed from a 3d printer, which I intend to equip with an array of 15 x 3 mm Neodym magnets to hold down a steel plate. The steel plate itself is not and can not be equipped with magnets. Theres a heated aluminium bed between magnets and steel plate and the...

Can we predict the movement of a magnet in a uniform magnetic field using Maxwell's equations? What if the magnetic field is variable, for example if we have two magnets moving in a reference frame? Thank you for any answers and I wish you a Merry Christmas! :)

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...

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...

I recently watched this Varitasium video where he explains the magnetic field due to a current carrying wire. In the video he explains how what we see and describe as the magnetic field produced by a current carrying wire is actually just a electric force caused by the an imbalance of charges...

These are magnets which are programmed according to the motion that is there in gears( transmitting motion from one shaft to other). To improve effificiency of gear; these magnets are kept inside the gear tooth such that whatever may be the error or to achieve constant velocity ratio these are...

It is now a one month completed for my research on magnets all way around on internet. During this session, I got to know that domains don't lose their energy until they are completely destroyed. So I am very much keen on the question that can magnets produce force without losing any energy?

Hello, I wanted to know, if someone knows of a realistic option of, how to cut barrium ferrite magnets without using a rock saw and without demagnetizing the magnet obviously? Thanks in advance everyone.

Hi! I'm curious to know, whether it is possible to produce electricity by moving a piece of metal over a magnet (i.e a immobile magnet and a moving piece of metal close to the magnet), and how this would be done in practice.

Homework Statement Given 2 magnets of equal weight (w0) and each with a magnetic strength (t0) placed inside a straight hollow cylindrical tube. One of the magnets is attached to one end of the tube and the other magnet is free to move inside the tube. The other end of the tube is open to...

Is there any study involving real magnets behaviour shot through Stern-Gerlach gates? I've seen something using rather large magnets[1], but still the pattern showed two bulges. I if suppose using very small magnets the split-up would be much clearer. After all these magnets are not simply...

I just took physics 2. We learned how to calculate the force of a magnetic field on a current or moving charges. What we didn't learn is how to calculate the force of attraction of two bar magnets or electromagnets for that matter. I'm building a coilgun and having a set of equations for this...

My little home made air-core solenoid makes 1.5T, why is it that superconducting electromagnets often aren't stronger than one would expect. Take the japanese maglev train for example: http://www.supraconductivite.fr/en/index.php?p=applications-trains-maglev-more According to this article the...

so i am literally one step away from producing a floating skateboard powered by permanent magnets, so here's what i wanted to check, to make sure I haven't missed anything obvious vertical lift achieved by using vertical repelling fields rotational motion is controlled by counterbalancing the...

Hi folk Is there a method to calculate the magnetic energy stored in a permanent magnet ? Thanks for help

In a cyclotron, I understand that a uniform magnetic field is used, oriented perpendicular to the plane in which the particles accelerate. This field is created by two cylindrical permanent magnets whose opposite poles face each other,as I understand it. What formula(e) determine the strength...

Hi, I saw this video and I can't explain why the magnet is propelled to the end of the coil with such a huge force. Can someone explain it in clear terms. I also tried to use Flemings left hand (or right hand) rule but it did not give me a satisfactory answer. Thanks, SM

So I know why magnets repel, it is to do with the orbit of electrons and all that. I also know that you do not actually touch anything, there is an atom of gap between it or something like that, because the electrons have a negative charge. But when magnets attract, what is going on? And do they...

In my experiment I am performing a collision with two carts with magnets attached with photogates and a labquest on an air track. I pushed the carts together and made sure that the carts did not come into contact. Based on my knowledge of collisions, I believed that the collision would have been...

Settle a bet: A reasonable sized (believe it is 2HP) router will not have any permanent magnets inside it upon tear-down. Instead, it uses an electromagnet. Correct?

Hey everyone, I have been doing some research in regards to floating an object, and possibly have it rotate. I am thinking magnetism is the way to accomplish this, but if anyone else knows another method I would love to hear it. I created a simple diagram on what I am trying to accomplish...

If I have 2 dissimilar magnets and push their North (or South) poles towards each other, how do I calculate how much force they will repel with. Again, I'm asking for calculations since I'd like to know before I buy magnets. I'm guessing they are either additive or they only push with a force...

I am trying to calculate the forces (in Newtons) between a permanent magnet, and an electromagnet. All I can find is interactions between permanent magnets, electromagnets, but never both and it is getting really confusing for me to do the calculations. So basically, if I have a permanent...

First off, I am new here, so please don't tear me apart too hard if I miss or misinterpret something, I'll cotton on eventually :D As I understand it, when a permanent magnet repels an oppositely charged object, such as another oppositely charged permanent magnet, no energy is technically being...

Hi I'm thinking about making an instrument to show the force on a wire carrying electric current for students in lab. A normal wire which levitates from ground after it has current flowing in it. We have the following equations F = ILBsin(a) W = ALg 'A' being the mass of unit length of the...

What I mean is if I have 2 cylinder objects made out of a light wood for example with 6 or so magnets on either face spread evenly and another magnet behind it causing it to spin could it generate a good amount of torque to shoot a small projectile between the two cylinders. To give you a better...

To elaborate more on my question: Is it possible to send metal balls through a pipe with magnets arranged a certain way which could hit a target with force. I've seen something similar done before but I think the ball was also a magnet, is that the only way possible?

Homework Statement This question is from Birger Bergerson's textbook on Equilibrium Statistical mechanics. Derive the relations C_H-C_M = \frac{T}{\chi_T} \bigg(\frac{\partial M}{\partial T}\bigg)^2_H \chi_T-\chi_S= \frac{T}{C_H} \bigg( \frac{\partial M}{\partial T}\bigg)^2_H...

Hi, I'm trying to calculate the flux density of a magnet, I can get all but one of the values needed to calculate it. Does anyone know how/where to get the z(distance from a pole face on the symmetrical axis) value?

Hello I have magnetic sheets A4 sized that could be bent but not enrolled, having a thin thickness. I want to cut them in a circular shapes. The idea, is there any possibility to make one of them (or other material same physics) positively charged and second negatively charged; then have...

We often here replies to answers with Why? Why does spacetime curve? Why is a magnetic field what is is? The following excellent explanation by the late great Richard Feynman explains... enjoy...

Basically my question is: if an anion is placed by the negative poll of a magnet will it push on the particle?

Physicists often speak about permanent magnets as if there was a theory that explained why they exist, and this theory is often assumed to be the Ising model or something very much related to the Ising model. However, everybody knows that the Ising model has a severe issue with the artificial...

I need help find a electromagnet suitable for this http://imgur.com/a/vkm4T Each electromagnet (the 3 in the center) needs a repelling force of about 20 to 40lbf. I stupidly bought these from amazon http://a.co/aSftIat. Its a holding electromagnet so the N and S poles are essentially on the same...

Charles Link submitted a new PF Insights post Permanent Magnets Explained by Magnetic Surface Currents Continue reading the Original PF Insights Post.

We know that the attractive force between the opposing poles of identical permanent magnets is a product of their field strength and that the total force diminishes as the distance between them increases. If we assumed the magnets to be point entities, the formulation is the same as that for...

Hi I am confused about rotating magnet. Feynman lectures on physics 13–6 The relativity of magnetic and electric fields, http://www.feynmanlectures.caltech.edu/II_13.html , deals with two inertial frames. Wire is charged in some inertial frame. Can we apply it to tangential parts of curved...

I am having difficulty thinking through how a ferromagnetic substance is permanently magnetized. I think I understand that when for example a sample of iron is heated above it curie temperature and then exposed to an external magnetic field , the sample will become permanently magnetized. The...

Hello, I wanted to ask a few questions regarding magnets and batteries, and EM induction. First off, could I use batteries to replace a low voltage dc power supply, like say 2 V or so by connecting the ends of the battery in series to a circuit? As an extension, could I connect two batteries in...