Magnet Definition and 912 Threads

Ladies & Gents, Instead of applying current to a non-magnet to induce magnetism, is it possible to apply current only to temporarily de-magnetize a magnet (natural or man-made)? This would seem to use up less electricity, especially since the default mode for a desktop application I'm working...

Good day everyone. I have two magnets where if I rotate them 20° they disconnect. It has a 0.4 N* m force of torque. I want to make them move with a motor. However I need it as little as possible. So after doing research I found tiny motors that are around 4000 RPM. It doesn't mention the HP...

I have a question why a magnet's magnetic field or a coil's magnetic field will not oppose the Earth's magnetic field? Is it because the Earth's field is not strong enough or the magnet/coil doesn't cover enough square area? What formula's would I use to figure out what strength or area I...

If a static magnet attracts an object A, where does the kinetic energy that A acquires come from?

A bar magnet will have a definite magnetic dipole moment, irrespective of the presence of an external field. Why is the moment, then, always defined in relation to the torque it would feel in an external field? Is there any other definition for the same?

My 7 year old child asked me today about magnetism. His question was "Does the magnet pull in the paper clip, or does the paper clip pull the magnet" . He then said to me "If i tie a rope to a tree and pull on the rope with enough force I will be dragged to the tree, so how do you know which...

Hello and good day. I am currently involved in research that seeks to utilized a Walker Scientific power supply and magnetic. The system is old but functional. We seek to utilize the magnet in order to conduct some low temperature experiments. We need information on this power supply, of which...

Homework Statement There is a magnet that approaches the loop as in the figure. There is already a counterclockwise current in the loop. What happens to the current in the loop? Is my reasoning correct? Homework Equations The Attempt at a Solution Since the flux is increasing in the loop...

Dear helpers, I working on an projekt for the University and for that I have to calculate forces between different magnets. The question that I have is: "Is there a way to calculate the force between two magnets if one is completely known and the other unkown. But you know the B-field of the...

I formulated a statement about the repulsion between a permanent magnet and an air core coil (electromagnets without a ferromagnetic or ferrimagnetic core), and I believe this statement is true, but I would like to seek the opinion of others about it: "In a system where an electromagnet made...

I have the first and second orders that I use in a magnetic simulator, but i need the thirth also to do also with magnetic cylinders accordingly paper: Do anybody have it in any code? I should pass to C++

Lets assume we have a 1 foot square bar of Iron. I realize that unpaired valence shell electrons in an atom of a substance like Iron, all with the same electron spin---either +1/2 or -1/2---are consistent within the same atom, as indicated from the aufbau principle and experiments. So for an...

I wonder if there is a way to calculate induced EMF in closed loops around bar magnet, which is traveling with constant velocity v to the right as depicted?

I'm sorry if this question is a little abstract, but would appreciate any guidance! It's for a DIY project I am considering. Suppose you have a flat panel mounted on a wall, and a very strong magnet that will move in any direction on the plane of the flat panel. Through any possible arrangement...

Homework Statement A magnet is moving with constant velocity vector ##\vec V##. A charged particle fly through it. At first, the objects are place very far from each other, and the charged particle velocity vector is ##\vec V0##, after the charged particle cross over and fly away from the...

The setup for one magnet Introduce a magnet: Inertial Frame 1 (or lab frame) A frame where a magnet is seen to move with uniform velocity v and carries a uniform polarization P while a point charge Q is seen to be stationary at time t=0. Inertial Frame 2 (or material frame) A frame where a...

Can you charge a capacitor with magnet and wire? Can a wire attached to a capacitor be given amperage by a stationary magnet? Can the wire be made to a short length so that the magnetic field creating the current causes the current to reach the capacitor to charge it? I imagine this doesn't...

Me and my friend want to make a strong as possible (made from permanent magnets) homemade metal separator for seeds. We are not good in the physics of such level, so we need consultation. We want to try neodymium magnets for our separator. We learned that magnetic flux density could be reached...

I was wondering if it was possible to create any shape of magnetic field. If yes, what would it take to do so?

In a DC motor as I understand it, a current is passed through a coil of wire within a magnetic field. The magnetic field exerts a force on the current perpendicular to the direction of the current. This force causes the coil to spin. Is the coil is between the north and south poles of 2 magnets...

General Information: A coil that is wound on a magnetic core is placed in between two permanent magnets as depicted below. The coil is fixed and the magnets are affixed to a shaft and can rotate freely. Assume that there is 0 friction for the purpose of the following questions Note: arrows on...

greetings. I designed a system on simulink. it is missing a pmsm. I found a block on simpowersystems in simulink nde matlab. I hope that this engine provides a nominal power of 96kw and maximum of 100kw. so how to test it? to verify that this engine can deliver these two powers? cordially. said.

Could anyone point me to the proper formula to calculate the magnetic field strength in the gap/hole(ID) of a diametrically magnatized ring magnet. https://www.skycraftsurplus.com/rp9291magnetdonut17odx08id-1.aspx

Hello, I have a question. I would like to create an electromagnet that is generally stronger than a standard fridge magnet... Right now I have this set up, (please tell me if what I am doing is wrong or unpractical). I have 10 AA batteries ligned in parallel to a 3 inch iron nail. I spliced a...

Homework Statement Homework EquationsThe Attempt at a Solution As the magnet moves in and out of the coil , flux linked with the coil changes , as a result an EMF is induced in the coil . A current flows in the coil . The current depends on how fast the magnet is moved . Current will vary in...

Homework Statement Homework EquationsThe Attempt at a Solution The magnetic field lines due to the infinite wire will be clockwise .When P is the midpoint of the magnet , Magnetic field at the South Pole will have a component upwards and a component towards right .This means S will...

I would like to receive some input about this "equation" formulated by me, a=f(i), regarding a system with a permanent magnet and an air core coil acting as an electromagnet, as described in the image: I understand that the acceleration provided to the toy car will be a function of the...

Hi, I am looking for the formula of the magneti field along the axis of a axially magnetized cylindrical magnet. Unfortunately, there are quite different answers on Internet. Is the uploaded formula (where R is the magnet radius and L its length) correct?

Homework Statement You have a circular coil, and two metal plates a and b. The north pole of a bar magnet is moved away from the coil at a constant velocity(assume the bar magnet and the coil lies along the x axis). On which plate will the excess positive charge appear? Homework EquationsThe...

I saw a post where someone was granted access to a 1.5 Tesla MRI. After some research I discovered a 3 Tesla MRI. How strong is this magnet?

Hi, I was pondering a question after seeing a video about chaotic magnetic pendulums. If you were to suspend a magnet on a pendulum above a repelling magnet, would it stop moving or would you get perpetual motion? My guess is it would stop moving but I can't think of how. Gravity would try to...

Hello. I have an assignment to submit and I really want to get full marks/know where I went wrong If anyone has a tiny bit of free time would you mind please checking my homework? Even if you just check 1 page I will be so grateful. Thanks again https://imgur.com/a/rHVdjzn

Hello, I am considering an attempt at building or modifying a device inspired by the following, as well as others: I don't know how I would make a driver for such a thing. Would it need to be software driven for example? Any input to point me in the right direction would be very helpful to me...

Hello, I have four questions. As it stands now, I don't have the necessary materials to test this myself, which is how I'd prefer to learn the answer. I still plan on doing this experiment for fun once I can acquire the necessary components. This deals with Lenz's Law. My goal is to maximize...

Homework Statement Homework Equations Emf=B l V V is (velocity) F=QVB The Attempt at a Solution Emf=BLV Work=QBLV Force=BLV how come V=Q/m. its not possible or is it?

Homework Statement [/B] Hey, I'm having some difficulties with my physics project and I hoped someone could help me out. We have to calculate the magnetic field, but first we need to know the flux. This is the setup we got: We have to let a magnet fall through a PVC tube. The tube has a coil...

I have a 28x15x7 stainless steel bearing mounted close to a powerful magnet and the magnet courses some drag when the bearings turns. This is no problem in this design, it’s a hand operated lever so very low rpm and I was even thinking that a magnet might me a good way to add some dampening to...

Homework Statement 1. Circuit moves downward while cylinder magnet is fixed. 2. Cylinder magnet moves upward while circuit is fixed. Gain emf in circuit. Homework Equations All those maxwell equations... F=v x B The Attempt at a Solution [/B] So first question is not that hard...

I have been researching for quite a while about this subject and I only got more confused. I want to evaluate the repulsive force between a magnet of 52 MGOe and an electromagnet. The goal is to generate a repulsive force of say 75 Newtons. So I am using a neodymium magnet N52 how can I figure...

Is it possible for a horseshoe magnet to have only one pole? For example, if i take a horseshoe shaped iron core and wind a conductor such that both the ends of the horseshoe have current flowing in the clockwise direction, then both ends are south poles. Is this possible? In that case how are...

I am currently designing a three phase permanent magnet axial flux generator, but have a question regarding the voltage induced in the copper coils. Faraday's law defines this voltage as the number of turns in the coil, times the change in flux (external magnetic field times area of coil) over...

I am looking to try some design ideas using PMs for alternator design. I am a retired EE so I do not have corporate capital for simulation software. Does anyone know of low to medium cost simulation software that might be workable for basic flux/emf/etc calculations and modeling? Or other...

Hello, I am wondering if one can create a magnetic field which can be seen by a human eye? I have learned that light is nothing else but electromagnetic field with a wavelength between 400-800 nm. Colours correspond to different wavelength within the above spectrum. So isn't it theoretically...

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! :)

How can the "end effect " be reduced on a long Bar magnet where the (for example) North pole is along the length of the top side. For example a 0.5 cm square bar say 5" long is stuck (South) onto a metal backing. The center length of 4" has a linear field effect but the ends have a bloom...

As the permanent magnet is magnetized by donut shape coil, thus field B = 0 outside. How can I know if seller screwed me or not?

Homework Statement A small but very powerful bar magnet falls from rest under gravity through the center of a horizontal ring of conducting wire, as shown in the figure below (on the left). The speed-versus-time graph, in arbitrary units, of the magnet will correspond most closely to which of...

Hi, i'm finishing my final degree project, it's about a new type of pallet conveyor dragged by magnets. I know for a fact that magentic force is inversely proportional to the distance squared, and I've designed and built my prototype with that in mind. Now I'm writing my final report and i need...

Alright, I'm trying to calculate the power requirements for a 30 Weber =( 30 Tesla/m2) Strong magnet According to this document it would require about 88 MW using a steady-state copper coil magnet The question is, how much power is required to do the same using cryogenicly cooled...

If an AA battery were placed in some kind of ideal conducting 'ether': 1) Would current flow, and if so, what would the flow of electrons look like? 2) How would the magnetic field look? (I imagine that if there was an electric current flowing, that the magnetic field would look a little like...