Magnets Definition and 538 Threads

It seems like magnets have an enormous supply of energy. Where does a magnets energy come from? It almost seems like it has a never ending supply of it. Think of this thought experiment. A permanent magnet is suspended 1m away from the floor. A steel ball is placed onto the floor under the...

Neodymium-Iron-Boron magnets have a relative magnetic permeability of 1.05. According to the formula: B = μ0 * (H + M) Both the magnetizing field H and the magnetization M contribute to the magnetic field B. The magnetization M has sources and sinks, so therefore it follows from Maxwell's...

Hi, I study physics and I know what the concept self-inductance means, and in one of my study books, a figure like this was used to explain the self inductance in a coil As shown in the figure, two electromagnets are connected together and the current is passing through them and would produce a...

Hi, I was doing an experiment with Neodymium magnets and a long copper pipe (3cm internal diameter) to see Lenz's Law in action. At first I used a long bar magnet (about 15cm long) and there was little resistance to the magnet falling through the pipe. It was only slightly slower than a...

Hello I am a a grade 11 learner and I am trying by all means to calculate force between magnets. I know that the strength of a magnetic field is determined by the size of the magnet.

Hi, I have been asked how many times a magnet can magnetize a magnetic material before itself get demagnitized. The example in hand was the question about a strong neodymium magnet that accidently ruined a ferrite magnet. The next question was then why this neodymium magnet appears to not lose...

I am wondering if it is at all possible to create a magnetic board which is capable of repelling magnets. I am looking up magnetic levitation and would like to make a DIY version at home. Any tips/tricks to make this. Thanks in advance!

If you want 2 magnets to touch when the poles are the same . Would it matter how you do it,moving them vertically towards each other or horizontally?Does it mater how you get them together and separate them? Would it use the same energy to join them horizontally as they would make repealing...

Say I place a magnet on a table, and I have a metal in close proximity. Will its magnetic field change due to the presence of this metal, however minute? What if I had another magnet or the table itself is made of materials the magnet is slightly attracted to? Does this phenomenon even exist?

Hello PF! I am writing a scientific report about magnets, but have really no clue how magnets actually work? Research has yielded a few ideas, specifically from here and here. However, sometimes (in iron, nickel, and cobalt for example) you’ll have one or more un-paired electrons. The...

Hi, hopefully someone here can help me! I'm interested in Halbach Arrays and specifically I want to make a circular array in which the field is amplified away from the array (as in above or below it), not to its inner diameter (or exterior circumference). Is this possible? On the web I've seen...

Hello PF! I am about to conduct a physics experiment to write my high school level paper on. I initially was going to investigate the Gaussian Gun, but my physics teacher has said that I need to have real life, practical applications of the model, and to also have a variable I can change and...

Hi everyone! My knowledge of physics is very very basic, so I just found this great forum and I think it would be great to have a feedback from people who know. I am in development of a project that involves a laptop sleeve and some magnets. I've already done my research and found that they...

Please excuse my ignorance, I am 11years old. I have been wondering will magnets work in a vacuum A.K.A SPACE. Thank you for any and all answers.

I've done some research on Google but have found no of relevant information. I basically want to create a rope effect using magnetism. The objects will ideally maintain a certain distance from one another - the distance can vary to some degree - but must not be attracted too closely nor...

I'm back in school after decades away and taking alternative energy .. just because it was interesting. In the wind power class we talked about Hugh Piggot and the home brew HAWTs he makes and teaches. That gave me the bug to see if I can do it. I'm pretty sure I can buy a used turbine on EBay...

I am trying to calculate the forces between a simple sphere neodymium magnet on other iron surfaces and magnets. I did a lot of research but still not sure what equation to use or how to apply them. I found the following equations here (https://en.wikipedia.org/wiki/Force_between_magnets) F =...

I'm talking about how like the atoms expand and the electrons get farther away from the nucleus. This might be a stupid question but how does that make it less magnetic? Like what do the electrons being farther away have to do with how strong the magnet is?

I am Telecommunication student but interested in motors.Especially, power generators.I was wondering why permanent magnets are not used in synchronous motor's stator or rotor? Is induction motor more efficient than permanent magnet used motor? What about in power plant generators, do they use...

My dad is working on a project where he intends to convert mechanical into electrical energy, and he was wondering if a particular magnet and coil configuration works for electricity generation. And if it does, how are the voltage and current calculated. Lets say: The coils have a diameter of...

Say you have a coil connected in a closed circuit. You then move a magnet inside of the coil and it remains stationary inside of the coil. Is the magnet, even though it is stationary, still inducing an emf in the coil or is it not? I'm guessing it doesn't induce an emf in the coil because...

Hi, i am an student of civil engineering and i am doing my graduate thesis. so sorry if i misspell, english is not my native languaje. so, here we go :D Homework Statement Before entering in details you (whoever you are) most know: The system is scaled for obvious reasons. The system consists...

I'm doing an experiment regarding Nickel's time for a Curie point. The nickel will be connected to a wire on a pendulum and will be attracted to a neodymium magnet, but it will not be touching it. A candle will be placed in front of the magnet so that when the nickel moves toward the magnet as...

Hi! This might be a dum idea but here goes. Say you have 3 items. One weak magnet and two ferromagnetic materials of different susceptability. The magnet is strong enough to saturate the first material bot not the second. But since the saturated field in the first material is larger than that...

Thanks to anyone kind enough to help check my logic. Using 13 gauge copper wire and a magnet I can generate .05 watt every time the magnet passes the coil (according to the voltmeter). Am I correct in assuming that if the magnet passes the coil 60 times a minute, then (.05 watts X 60rpm X 60...

Homework Statement Homework Equations no equations required The Attempt at a Solution so here are my answers, i just want to know if they are correct. also, I am really confused about the function of the commutator in the DC motor, the answer i wrote for part b) was based on research off...

So I was thinking about something quickly in science while my Science teacher told me about electromagnets creating electricity and stuff. Then I thought, what if there was 2 big magnets both negative together creating friction in the middle?(idk) Then a nice big pole which transfers Friction...

I am curious about the possibility of building a large permanent magnet that could exert a huge pushing/pulling force of about 135 million Newtons. In answering the questions, I wanted to have these following points addressed: 1. The magnet is 30m wide by 30m long...would have to push a...

Two magnets, like poles facing, will "levitate". And they seem happy to do that forever. In common experience, it takes energy to jump, an airplane to generate thrust to convert to lift, or a helicopter to hover. "Hovering" for the local TV newscopter, or a SpaceX rocket is an energy...

Can a magnetic Halbach array have less than three (i.e. two) magnets in the array? I can't seem to figure this out quickly with google. TIA!

Homework Statement A bar magnet floats above another bar magnet. The first has mass u1 and magnetic moment m1=m1k^ and is on the ground. The second has mass u2 and mag. moment m2=-m2k^ and is a distance z above the ground, find z 2. Homework Equations I assume I need to calculate the magnetic...

Hi, today i had exams in Physics and my Professor as an extra points question was asking the following question. We have 2 magnets, one is named Alpha with dimensions 100 cm length, 70 cm width and 2 cm thickness (100x70x2) and the other one is named Omega (200x100x5). Alpha is moving...

well i came on here doing some research on a home project. i would like to know the what the energy output a turbine has and if there is an electromagnet capable of turning off and on quickly while repelinng other magnets, and the amount of energy it would use

When two permanent magnets attract, their magnetic fields reinforce each other, whether they are stacked on their ends, in which case they are pointing the same direction, or whether they are stuck on their sides, in which case the two magnets are pointing in opposite directions. Everyone here...

Hi, I'm working with a magnetic levitron project and I've borrowed a professional levitron to see how it works. When I remove the back cap, unexpectedly I saw a square shaped magnet instead of ring magnet. But it acts like almost a ring magnet. I'll explain the difference with images below. At...

I recall that the energy stored in a magnetic field is half the volume integral of the dot product of magnetic field and flux density vectors (H and B). When you place a piece of iron near a magnet, it does a work by attracting it. If H is 0 (I think there is only the magnetic moment vector M...

Is it possible to partly demagnetize neodymium magnets in the flame of a candle? Those magnets are made up of Neodymium, Iron and Borium. They have a Nickel-Copper-Nickel coating. The Curie temperature for Neodymium magnets is 310-400°C. Neodymium (magnetic powder) burns but does the coating...

The pole method of magnetostatics is presented in many E&M textbooks, particularly the older ones, to do computations in magnetostatics and even to try to explain permanent magnets. An equation that arises in the pole method is B=H+4*pi*M (c.g.s. units), where H consists of contributions...

I bought a couple of bar magnets at the local hardware store. They were acting so strangely. I couldn't figure out where the poles were. Finally I realized each magnet had four poles! They weren't quadropolar, rather half of each bar was magnetized one way and the other half the other way...

I understand that a cathode ray will be attracted to one pole of a magnet, while being repelled away by the other. The cathode ray, being electrons and thus negatively charged, must definitely be attracted by the positive pole of the magnet, while being repelled by the negative pole of the...

In the below video it is shown that rpm is increasing by using external magnetic field . can i know on which principle it is based on?

generally in the pmdc motor the armature will rotate.As it works with the help of magnets ,if i provide external magnets to motor ,there will be any change in the rotation of armature?

Hi everyone, I have a little magnets project for school i need to accomplish and I'm a little stuck.. hoping someone with the right knowledge of magnets could assist me here :) I need to build a small magnetic gate which can push forward a steel ball (but not too far away). the idea is to...

How can you make something move forward or backwards with magnets. I didn't got it in here : Minute : 5:00 forward It said how the train move but i don't understand why it moves. It makes no sense for me because it is the same force that keeps the train floating?

Hi all =) I am interested to find the forces and torques between two (diametrically magnetized) cylindrical permanent magnets (PMs) placed within a vicinity, as shown below: The NdFeB PMs placed beside one another with a distance, d. Both are rotated by independent external sources (I have...

if I had a motor with a pendulum and a magnet at the end of it, and attached to this motor was a frame holding a another magnet that is close enough to the pendulum to exert force on it when it is horizontally positioned would that force make friction with the inside of the motor creating thrust...

Hi, I have been reading this fascinating paper here: http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4484.html I'm struggling with some of the biophysics, and it would be great to get a discussion going. In particular, I was struggling with the statements where it says "The two...

1. The magnetic field at point P due to a magnetic source S1 is represented by ==>. Can a bar magnet S2 be brought close to P so that the total magnetic field at P due to S1 and S2 is zero? Explain your answer.2. None3. Yes, this is possible if both fields at point P have the same magnitude but...

Homework Statement Two small bar magnets X and Y are released from rest at the same height above the ground. X falls directly to the ground, but Y passes through a metal right which is fixed with its plane horizontal. Does X reach the ground: (A) at the same time as Y, (B) before Y, (C) after...

From my little understanding of magnetism and the magnetization process, in order to magnetize a magnet it is better to have a closed magnetic circuit. But how does an air gap affects the magnetization "strength"?Example: Assume that we have a unmagnetized horsehoe magnet with a coil around it...