Magnet Definition and 868 Threads

A really basic question: since room temperature (300K) is much lower than the Curie point of iron (1043K), the spins in an iron bar at room temperature should be lined up even when the external magnetic field B=0 Then why can't we use any iron bar as magnet? Instead we have to rub the iron bar...

Hey guys its Saturday and the beer has been on menu. So the topic was " drones using magnet" and little magnets would be placed on propellers and thus they would circulate. Power generated from that could be used in micro controllers to control the movement of drone. Can someone tell me how to...

I'm trying to make my own simple magnet generator project Like these: http://amasci.com/amateur/coilgen.html http://www.wikihow.com/Make-a-Simple-Electric-Generator with the following materials: 2 1.5X1.5X1/8" square magnets https://www.amazon.com/gp/product/B011FNB7WK/?tag=pfamazon01-20...

I'm a high school physics student. I want to do an experiment to see what happens when a high frequency alternating current goes through a magnet. To create the high frequency alternating current could a photo resistor do that for me? Does the photo-resistor create an alternating current with a...

Hello, i've recently found the post "How to calculate the force acting on a magnet placed in a magnetic field?" at http://physics.stackexchange.com/questions/20258/how-to-calculate-the-force-acting-on-a-magnet-placed-in-a-magnetic-field in another Forum and the answer said smth about an...

I've been looking for that question for months but no luck. According to the classical electrodynamics the attraction between two magnets is due to the inhomogeneous magnetic field acting on the atomic loop currents (through Lorenz forces). The homogenous field does not produce any attraction...

I thought i would do some digging into the wonderful world of magnets, and I found some things that... well are real head scratchers... I was wondering if anyone here could help me wrap my brain around non uniform acceleration. I'm trying to calculate velocity using distance and varying...

Homework Statement If we have a system that is shown in the picture, the upper piece is magnet, and if we know the following data: S = 1cm2 which is area of material, S0 = 1.2cm2 which is the area of fissure. To bring these tow pieces of this system magnetic induction in the fissure should be...

Check out the following video of a magnet falling through a copper pipe. http://www.sciencealert.com/watch-what-happens-when-a-magnet-is-dropped-through-a-copper-pipe

Hi, I've been doing reading on Halbach Arrays moving over surfaces and generating repulsive forces. From my understanding, the moving magnet induces a circular electric current in the metal track, which gives rise to a magnetic field. However, I'm having trouble understanding why this field...

Hello, I have been looking at superconductors lately and was wondering if there was anywhere I could get a small superconductor online. I realize for it to actually conduct it must be incredibly cold, but I was wondering where I could get a metal that allows for superconduction.

I've always been taught: North poles attract south poles. Yesterday after studying electromagnetism, I've a question to ask. Here's a diagram: In circuits like these, this is how the north and south poles of these electromagnets are defined. Now my question is, is the reason that the South pole...

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...

Can someone tell me if the parts of what I've done are right, and explain the questions I've missed. We have just done a lab on split-ring commutators and I'm currently doing a lab report. "Explain what is meant by the torque of an electric motor. Use a diagram" I've said that 'The torque of an...

Hello guys, I am trying to build a permanent magnet generator, I have 48 magnets and 18 coils, and I am hesitating betwen 2 configurations. Configuration A: 2 huge steel plates with 24 magnets on each and an 18 coil stator between them or Configuration B: 4 smaller plates stacked to sandwich 3...

I found this formula to approximate the inductance of a coil of wire. But what if a solenoid were composed of N separate loops, where each loop of the solenoid is connected to its own battery? That is, what if the solenoid had the same number of loops and the same geometry, except that each loop...

Hello Everyone: Take a look at the following diagram Assuming the coil build above. How would you determine the force pushing-pulling the Neodymium Magnet in the center of the plastic pipe. I know the number of turns, length, amperage are in effect.

Homework Statement A electron cyclotron has a frequency of 2450 Hz and a magnetic field strength of 50T.? a) what's the speed of the electron? b) what was the voltage on the electron gun which projected the electron into the cyclotron? Homework Equations Givens: r=.4m B=50T f=2450Hz...

Heat seems like the easy answer, but interparticle collisions should decrease as the ball slows.

Hi, I would like to evaluate the required work to create a 1 T field with a permanent magnet. I saw a few formulas on the internet, but I don't know how to use them correctly. The main one are B={{\mu }_{0}}\left( H+M \right) {{W}_{mag}}=\frac{{{B}^{2}}}{2{{\mu }_{0}}}Vol Let's say I know all...

When you switch on an electromagnet (who's north pole is pointing to the left), is it the same thing as if you had pushed a permanent magnet to the left? Or to the right? I believe it's to the left. But apparently my textbook thinks it's to the right. Who's correct? Why I'm asking:I've attached...

Hi. Can somebody make a calculation for me? how strong do a magnet need to be to lift a mass of 75 kg iron 1 meter straigth up in 1 second. Best Regards morten

How to control magnetic field produced by a permanent magnet which is being induced on to a coil ?

My fundamental question is, do opposing magnetic fields eventually degrade each other over time? If they do, is there a way to mitigate or eliminate their ability to degrade one another? If I had one permanent magnet facing up and another permanent magnet facing down hovering over it (with the...

Hello everyone. I am glad I came across this science oriented Forum site. I actually get there from Google and what I am deeply curious to know about is the amount of Maximum Voltage my 3.5kg Air Core Electromagnet can bear. The Core of the Solenoid is 120mm in height and 13inches in...

Hi Everyone , Can anyone explain why I am getting negative result with a large Neodymium N35 ring Magnet ? Br: Remanence field, independent of the magnet's geometry z: Distance from a pole face on the symmetry axis D: Thickness (or height) of the ring Ra: Outside radius of the ring Ri...

I'm doing an experiment on the effect of the speed of rotation of a rare Earth magnet on the voltage generated in a solenoid coil. I was wondering, how does rotating the magnet affect the magnetic field? The experiment setup is similar to the one below:

there is a toroidal coil , a magnet rotates in the middle of the coil , I wonder what happens when first the magnet that rotates is a permanent magnet , second case if the magnet that rotates is a electromagnet supplied with a certain frequency AC current? I wonder what kind of output we see on...

I have a project I'm working on where I need to have a model train be able to have an electromagnet hold its wheels to the track -- so that it can go "upsides down" and resist derailment. I'm making the wheels and the track -- so all options are on the table. If I used a steel track (say...

Here is my misunderstanding , for the example let's ignore resistance losses , say i have a infinite length of coil , and an infinite strip of magnets passing through that coil, each magnet separated by some distance from the next one , the strip of magnets move through the middle of the coil ...

Hi. Is it posible to make an equation to solve this: How many horsepower does it takes to remove a magnet with the force of 1 tesla, from a piece of metal. ? The surface of the magnet and the surface of metal is the same size. I gues the angel of witch the magnet is being pulled affects the...

Hi Just wanted to know, If I have two magnets of the same size with a pull force of say 30kg and use them to repel each other, the top magnet at a position close to the surface of the bottom magnet would be able to support around 30kg (I know repel force is not measured in kg). If I then...

Hi Just wanted to know, If I have two magnets of the same size with a pull force of say 30kg and use them to repel each other, the top magnet at a position close to the surface of the bottom magnet would be able to support around 30kg (I know repel force is not measured in kg). If I then...

I am looking to find the magnetic flux of a cylindrical magnet as it passes through a coil. I am aware of the complexity of magnetism, however, i am only looking for a conservative approximation of the magnetic flux. I found the formula ΦB = B · A, but is my understanding that the magnetic...

If I have a magnetic setup in frictionless, etc. area as follows: N / / / ---------------------S Will the "south" pole rotate up to the "north" pole, causing the system as a whole to rotate?

If a solenoid were wrapped around a bar magnet, and a charge were applied through the solenoid, would there be resistance?

Hello, for a project I'm working on i need a magnet that is attached to a spinning wheel to trigger a magnetic reed switch that's about a cm away every time that the wheel makes a rotation. I don't know which parts to buy because if the magnet is too weak or the switch too hard to trigger it...

There is an swinging metal pendulum. I put one polar of bar magnet below the equilibrium. What will be the effect of the intensity of the magnet to the time taken for the pendulum to stop? Please explain the theory specifically since I am quite confused. Thank you very much.

Hello, this is my first post, i only have what we call an O Level Physics here in the UK, but i have a strong layperson's interest in the subject, so I'm looking forward to picking the brains of the more educated people here. My friend's professor showed him something very interesting, all to...

Hi, I was wondering whether it was posible with a formula to measure the distance to which two equal magnets start attracting to each other. I was looking at this web page https://www.kjmagnetics.com/blog.asp?p=surface-fields-101 and I am not sure if this is the right formula. I have two...

I''m facing problem in modelling and analyzing a permanent magnet in 3D. kindly help me out.

Homework Statement The wire loop ##ABCD## is in a magnetic field of the long thin rod magnet with a magnetic moment per unit volume of ##\mathfrak{M}_0## and a cross section ##S##. The north pole of this magnet is in the center of the loop, and the magnet is perpendicular to the plane of the...

Heya, I am new to this forum and want to start with a tricky question... There is a cylindrical neodymium magnet, d = 40mm, height = 5 mm, hole in the middle (also round shaped cylindrical) d = 10mm. There is also a pure iron ball d = 12mm. The ball is set on a non-magnetic stand at 500 meters...

Hi All, I am wanting to buy the lightest, strongest magnet I can. Can someone please direct me or give me guidance on this issue? I am requiring a magnetic field of >5000 surface gauss. Any links or direction would be terrific, Thanks in advance, Dale.

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...