Magnet Definition and 912 Threads

Homework Statement A bar magnet is held stationary (with respect to the loop of wire) at the centre of the loop with the North pole sticking out one end and the South pole sticking out the other. What happens to the size of any EMF induced in the loop once the magnet has been replaced by a...

Researches from the University of Georgia, Princeton University and Oxford University report a new method for nanofiber production using a permanent magnet and ferrofluid – magnetospinning. Results of this research are published in Advanced Materials journal -...

Homework Statement As the bar magnet (see attached diagram) leaves the loop of wire, it experiences a force opposing its exit. I understand why, according to Lenz's law, a force would oppose the bar magnet's exit. I don't understand, however, what causes the force. In this case, the force is...

Assume a strong permanent magnet is suspended by a string over a metallic object. The magnet is slowly lowered until the object is attracted to the magnet. For this to occur the object acquired both kinetic and potential energy. Since the object comes to rest upon hitting the magnet, I assume...

1. So, during one of my classes, the teacher showed us a small experiment, and asked us to explain how it works. The experimented consisted of a tube, closed on both ends, and attached to said tube is what I think is a magnet. Now, everytime he rotated the tube, the magnet rised to the top with...

Based on what I have gathered so far, I don't see why a micro-scale generator wouldn't work, but then again I am a geographer with modest calculus skills. My biggest problem is not knowing how much I don't know, and I am hoping some kind and wise soul on PF can cure my ignorance. Let's say I...

Let's say we built a tunnel through the (arbitrary) center of the moon, and lined the surfaces of the walls with millions of loops of copper wire. If we dropped a massive magnet in through the moon, would it produce a substantial amount of current due to the magnetic field passing through the...

Hi, I'll give some background, say you've got a planar structure of thickness 'd', lying on the z plane. Also say the upper and lower surfaces are y = 0 and y = -d, respectively. The structure has scalar potentials inside it as so: As you can see the vector fields cancel out on one side, As it...

Assuming the stator and windings won't burn out, how fast can a magnet rotate before it structurally fails?

If the magnetic field strength is measured to be X Tesla on a large flat permanent magnet is there a standard formula for determining the force the magnet will supply as a function of distance from a piece of metal with well defined properties. I see the problem of different metals are going to...

Hi all, I have two identical magnet which measures 0.6T when I put my gauss meter on the top surface. I configured the magnets as below: I would like to know what should I expect if I measure the strength(Tesla)at the red round dot position? Would it be 1.2 tesla? Please advise. Thank you...

I want to know what methods there are for calculating forces by a current-carrying coil on a permanent magnet (the application I have in mind is electrical motors). I.e. given a geometry (like a CAD model of the magnet), the magnet type (e.g neodymium), and wire coil geometry, how are the forces...

i want to build an electromagnet which can attract small iron pieces(2-3 mm long) at a distance of 10 cm from the magnet.I am using 24 awg. magnet wire.Please help .answer these questions - 1) How long magnet wire (24 awg) do i need? 2)How much current 3) what shud be least radius of solenoid 4)...

Hi everyone! I posted this in the ME section as well but thought this would be a good section as well. I am working on a thesis project and have a question for anyone who feels they can answer it. I am trying to find the resistive force created when a magnet moves along a coil of wire. I have...

Hi everyone! I am working on a thesis project and have a question for anyone who feels they can answer it. I am trying to find the resistive force created when a magnet moves along a coil of wire. I have put pictures below but here is the short explanation: The pendulum, which is fixed at a...

1. I have heard that if you take 4 batteries and 2 non-coated wires, and run the wires + to -, with current flowing in opposing directions, with the wires in close proximity, that a magnetic field will be created between the 2 wires. Is this true? 2. Since photons have no charge, is there...

I'm messing around with Faraday's Law of Induction, and I will be using two magnets attached either side to a small bar inside two coils of copper wire, which I spin to induce a current. The design is basically this: http://amasci.com/amateur/coilgen.html My question is, what shape for the...

Hi Is there any fluid that is a permanent magnet at room temperature? (Ferrofluids do not retain their magnetic effect hence temporary). Thanks

I have a question about magnetic repulsion. Suppose I have a permanent magnet (axially magnetized) placed on top of the iron core of an electromagnet. I want to switch on the elctromagnet to repel the permanent magnet. (Please assume the permanent magnet is contained in some kind of tube that...

Hi Guys, I am going to restart the discussion in the following thread https://www.physicsforums.com/threads/calculate-pull-force-of-magnet.162157/ I working on similar system where i am interesting to calculate the pull force of permanent magnet on nanoparticles in water suspension. I am not...

1. Homework Statement This is for a physics lab I am working on. A flowing current causes the wire to deflect towards the right a certain amount that varies depending on the current strength. I need to derive the equation d=(L/mg)F where -- L is the distance between contact 1 and 2 both of...

For certain system i have to control two magnets , to catch up when they are " on " , and the opposite , how i can do that ??

Hello all, I'm working on a little side project to build something close to a Mag-lev system. I've researched loads around the magnets and have the info' on what conditions I need, current, Field strength, etc. But I'm having issues in finding how that relates to the movement of an external...

If a neodymium magnet sticks over a steel plate and you want to separate them, it is advised to apply force such that the magnet slips over steel plate. So I was just wondering what would be the quantified decrement of this force as compared to the case when force is applied axially to separate...

Dear Friends, The great problem lies in here : I have calculated the power requirement of an electromagnet. That Its huge . To minimize this power requirement I would like to see if its possible with super conducting magnet, but I am having a problem, because the power requirement are so low...

The equations are incredibly difficult, so I'm just after a general idea of how the force on a magnet bellow a coil changes with the distance to the coil. Shown bellow: Axial symmetry: o x o x cross section of coil o x o...

Hey! Not sure if this is a stupid question or not but I was wondering if a moving magnetic field could generate a current in a wire. I know that moving a wire through a magnetic field creates a current but what if you move around a magnet underneath a circular wire. Does that generate a current?

I have a problem in modelling a magnetic field of permanent magnet on ansys and comsol .I'm very thankful to you if you guide me or provide me a tutorial .thank...

Hey, guys, I find a interesting phenomenon. When an external magnetic field is applied on a current loop, the net torque will try to align the loop's dipole moment with the magnetic field. And considering that electrical loops could be regarded as electromagnet, we change the current loop into a...

HELP! Is it possible to create an electromagnet with one continuous wire with 2 like poles (i.e. both ends either north or south)?. Visualising it with the right hand screw rule for current carrying coils, it will be like the picture below, but one end of the coil will be as shown, while the...

So, I recorded the result of a LabQuest 2 Vernier Magnetic Field Sensor on different points of a plane, with a solenoid in middle with a 5 amp current running through. I want to compare my results with theory, but have no idea what equation I'm supposed to be using. I assumed it was B = μ0ηI/r3...

For diamagnetic materials, when an external magnetic field is applied, the electrons having orbital magnetic moment in opposite directions spped up. how does this happen? The direction of magnetic momwnt is given by right hand thum rule. If there is an electron revolving in anticlockwise...

Hi! I was wondering how I would go about solving a problem like this: (I have experience with up to multi-variable calculus and moderate level physics) So I'm trying to see if it's plausible to create electromagnets, which fit into gloves and/or boots, that would allow a person to climb around...

The field lines inside of a solenoid all go in one direction, right? So why doesn't a magnet that's placed in the solenoid simply get forced one way or another. I tried this at home by placing a magnet in the solenoid(near the outside of the coil so that it stuck out a bit), and when I turned on...

I have found an equation which gives the EMF generated in a coil when a magnet is spun near it, the equation is given as: E = FNAω × 10-8 volts. Where F is the field of the sample perpendicular to the axis of roation, N is the number of turns, A is the effective area of the coil and ω is the...

Hello, I want to create a motion using electricity, using the cheapest means possible (DIY). Basically I'm trying to rotate an object 90degrees when the current is on, and back to its original position when the current is off. The questions are: 1) Is this possible? 2) Can this be done using...

Hey all, I'm new here and hoping to enjoy glorious physics with you all! I have a problem and a question; the problem is I don't know much about electromagnets and want to build something rather involved using an electromagnet. XD The question shall be explained.. General Concept: I'm going...

Hey guys, I am building a superconducting magnet. The wire I have is extremely thin, and is flat. To put it more into perceptive it has a width and height. When I wind it into a magnet, it is more like a disk coil, or racetrack coil. Because it has a different geometry than most other...

Some 30 years ago I learned in the elementary school, that if I move a permanent magnet in a coil which ends are somehow electrically closed, than I need to apply force on the magnet, because the generated current creates a magnetic field which is against the magnet's field. However if the...

I am looking to open a series of valves in a chamber under 10" of lift(water) ~.36psi which are normally held closed by a very light spring and the constant air pressure. The valves are very light weight and range in surface size from approx 2 to 6 sq inches, or approx .72 to 2.16 lb of initial...

Ive had a look through the forums regarding this subject but I've found more questions than answers to issues that i would like to know firstly I am planning on building a perminant magnet hoverboard that floats on a perminant magnet floor slightly crazy i know the board is a skateboard in size...

Hi everybody. This is my first thread ever on this forum :S I'm in a first year physics class, and the other day we did a lab involving a c.c.c (current carrying conductor) and a magnet on a balance. The c.c.c was a wire which completed a circuit. One had a magnet assembly which was placed on...

Dear Friends Could anyone tell me whether we can stich (or) Join Magnets with Non Magnetic Materials? Is there any Possibilities? Thanks for Your Replies in Advance

Does an emf create across the body of a magnet when the magnet is linearly moving across its own field. If ABCD is a rectangular magnet of thickness t, AB is the north pole and CD is the south pole. If the magnet moves in the direction of t, that is perpendicular to ABCD plane, will there be an...

Hello everyone! I am a high school physics teacher, and I am witnessing something with a piece of classroom equipment I can't quite explain: I have a bar magnet with three poles. There's a North pole on the top AND bottom, and a south pole in the middle. This would make sense if two magnets had...

Say if I magnetize a hollow cylindrical ring magnet by placing a staight current carrying wire along its axis. It will be magnetized with magnetic field lines running inside the cylinder clockwise or anticlockwise! So there will be no magnetic field lines outside the iron body? If I have a...

Can I get the voltage generated by a vibrating coil around a magnet as a function of the frequency and amplitude of the vibration (given all necessary informations about the coil and magnet)? What would that function be? Also, what information about the coil and magnet would be sufficient and...

Hello! I am trying to understand a few properties of the ferromagnetic powder.I could not get the answers to these questions on the web, since any kind of phrasing i used, popped up search results that related to iron powder or ferromagnetic powder, which are manipulated and shape-shift using...

Hey, I have only a little experience with electronics, and I'm looking for a simple sensor for a magnetometer sensitive enough to detect about a gauss and accelerometer for detecting when something is picked up. As long as I can get a good explanation (data sheets can sometimes be cryptic) I'd...

Evening, gentlemen! Just a quick question for you guys... maybe more, if anyone's seriously interested. I've got a project going on at the university that I hope to get funding for in the future, which is the construction of a relatively small Bitter electromagnet. I say 'relatively' because...