Magnet Definition and 868 Threads

Hi! This is my first post on this forum, and I have two questions. First of all I'd like to mentoin that my math knowledge is at high school level + some basic calculus. Ah, and I haven't learned about (partial) differential equations yet. My physics skills go only as far as electromagnetism...

What property of the magnet determines which side of it is North and which side is South? I know that we are unable to separate the poles of a magnet (ie cut a magnet in halves and we get two magnets). How come?

Is it possible to make a magnet move constantly up and down, insider a container for example, without touching it or forcing it to move? I don't know much about Physics but wanted to ask this question as its been bothering me for a few days! I was thinking about how magnets may repel and...

Ok let's say we have an infinitely long magnet, with poles arranged like in the diagram. A positively charged particle is moving as shown in the diagram. Because of Lorentz forces, the particle will be accellerated towards you. Now change the frame of reference so that the particle is stopped...

I have searched and searched but do not know what gives rise to a permanent magnet. I would like to know why two opposite forces are produced at the ends of the magnet. The closest I have got to it is to do with electron spins becoming aligned. Help would be most appreciated Thank you

A 10-cm-wide, zero-resistance slide wire is pushed toward a 2.0 ohm resistor at a steady speed of 0.50 m/s. The magnetic field strength is 0.50 T. How much power does the pushing force, 6.25*10^-4 supply to the wire? What is the magnitude of the induced current? I got 3.13*10^-4 for the...

If a magnet is used to levitate another magnet (using the force of repulsion) can it be considered as doing "work" in opposing the force of gravity? If yes then why does the energy required to do this "work" not diminish over a period of time?

[SOLVED] Tension in a string of a object being pulled by a magnet Homework Statement An Iron bolt has a mass of 65.0g and hangs from a string 35.7cm ong. Top end of string is fixed. Without touching it, a magnet attracts the bolt so that it remains stationary displaced horizontally 28.0cm to...

A magnet will induce EMF when it passes through a conducting coil. Where does that energy come from? Does the coil do work on the magnet somehow? The B field induced in the coil should be parallel to the magnet's motion, so I would think it could not slow the magnet's progress. Does the magnet...

Hello, Suppose you had an iron magnet. What effect would an electrical current have on this magnet? Would it still retain its magnetic properties? Thanks in advance for the help.

with an odd shaped magnet eg a cone .. apex = N / base = S is the strength of the magnet the same at each pole ?

Possible to modify a magnet to be more "beamlike" I've been wondering if it is possible to encase a magnet in something readily available that would give it more beam-like characteristics vs. field. Basically, I want to have the magnet encased so that I would get full magnetic pull on an...

Hi, I am new to this forum, and I just want to say hi and I am glad that I am here. Now, I have one http://img235.imageshack.us/img235/3324/testra5.gif Isn't the magnet always staying stationary, in one position? Thank you very much. Best regards.

Are the force around the poles compressed, so it makes the poles of the magnet stronger than the other parts? Thanks.

Is the incoming flux (first peak) equal in magnitude to the outgoing (second peak) flux? Why? A magnet was dropped through a solenoid, this experiment was completed twice, a graph of Voltage (V) vs. Time (t) was made for each experiment. The area under each curve is defined to be equivalent to...

I have a few questions about magnetics. Let's say I have 4 individual magnets of equal size. 1.) When all 4 individual magnets come together and are held together by their magnetic force do they form 1 whole magnet with two poles or do they remain individual magnetics each with their couple of...

Homework Statement I have a source producing ions of He: He2+ and He+, they are accelerated towards a tandem accelerator, se atteched figure. They are accelerated with a voltage towards the first magnet, were a selection of the ions are made. We only want the He2+ ions the proceed to the...

which brand magnet wire is considered the highest quality, Belden seems to come recommended, any others would be appreciated

Dear all, 1) For a spherical permanent magnet, the magnetization M is defined to be pi/4u0*Br*d^3. My question is: if I attach 4 such spherical magnets together, would the magnetization simply be 4M? Where (website) can I find a good reference for these type of material? 2)...

Hi, What is the effect of "back e.m.f." on the torque output of a permanent magnet d.c. motor? I googled it but didn't get any results.. I just need a brief description to understand the concept.. Thanks :blushing:

I guess I do have to ask some questions on magnet storage. Especially over long periods of time. Basically, I want to know what the effects are if you store (relatively strong) magnets north to south with a slight gap in between (roughly 50mm between). N===S N===S N===S That's pretty...

why the direction of the current is determined by which way you move the magnet through the coil?

I have a flat rectangular refrigerator magnet. I was curious to where the N S poles were, so I took a standard bar magnet to it to find them. Curiously, the bar magnet does not seem to be repelled at any place of the refrig magnet. Where would the poles be on a flat, bendable refrig magnet?

Hi, I have a question about magnetism. If 2 magnets are used to pick up iron shavings, and the magnet are connect with paramagnetic material and turned into a U-shape. Should the poles at the end of each magnet by similar or dissimilar to pick up the iron shavings most effectively?

I noticed when I stick a cylindrical magnet on a smooth metal surface (longways) and roll the magnet along the surface, it does not roll smoothly. Instead, it seems to resist movment, then 'pop' forward into another position. It is almost as if the magnet has a preference on which side sticks...

Answer please. Thank you very much. I am talking about permanent magnet.

I'm trying to make an interior rotating mangetic field that will induce electron flow in an encapsulated closed loop coil. What I'm constructing at this time (not finished yet) is a rotating (0 - 1600rpm+) neodymium permanet magnet setup in a Halbach Array assembly. I understand that inorder for...

Is there a strength and/or field density difference between ring and disk magnets? I want to know which would create stronger eddy currents when dropped through a copper tube (which one would fall slower).

Answer please. Thank you.

I have designed a science experiment for my project in which i see whether a magnet gets weaker when it rusts. So, i take a magnet that is not rusted and see how many paper clips it can pick it up. Then, i rust it and see how many paperclips it can pick up after that. I need to finish this...

Hello, say you have a cylindrical magnet magnetized through thickness (not radially) and you drop it through a copper tube. It will slow down. Is there an opposite force on the tube? If you were to hold the tube in your hand and drop the magnet inside, would the tube feel heavier?

:redface: 1. i need to design an electro magnet that can lift a 1 Kg weight vertically with the minimum cost possible ANYONE GOT ANY IDEAS and i need it to be very presize i mean the measurements thanx

Sorry if this is a fundamental property or not, but I'm curious as hell. Today in class my proffesor had two identical iron rods. Same in weight and length. However, one is magnetic, and the other is not. He said, "You have the two rods and use of your brain. How do you find out which is the...

Nobel prize winner Richard Feynman explains in his sum over histories interpretation of Quantum Mechanics that photons go where time is least. If we consider that EMF are a lot stronger (in force magnitude) than gravity and if a magnet is emitting massive numbers of virtual photons, do we know...

See: http://user.web.cern.ch/user/QuickLinks/Announcements/2007/LHCInnerTriplet.html" What's the latest news on the LHC? How bad is the damage? How long will the delay be?

Hello All, In my projects, I am constantly winding coils and more coils, which all use magnet wire of various lengts and gauges. Most of the stuff, I buy from RadioShack or eBay in50' and 100' rolls. But since I go through a lot of it, I figured it would be worth the money to just buy a couple...

Everyone might have time to polish their theory. http://www.fnal.gov/pub/today/20070329_page01.html Fermilab Statement on LHC Magnet Test Failure

I have a 12 volt car battery hooked up directly to a 6 gauge wire that is wrapped around an iron rod. For some reason the wire can only last around 30 seconds and the wire completely melts and no longer works. How is it that a 12 volt battery has enough amps to melt a 6 gauge wire?

Hi, I have a permanent magnet (actually, an assembly of permanent magnets). I can calculate magnetic flux density induced by the magnets (when no other objects presents). Now, I have very small iron particles suspend in water inside a cup. The magnets are then placed on the outside wall...

Hey, this is a great 1 minute long video showing you how to make a homopolar motor using just one AA batter, a copper wire and a magnet. ENJOY! http://www.spikedhumor.com/articles/90173/Homopolar_Motor.html

Magnet through Loop (Faraday's Law??) A constant magnetic field passes through a single rectangular loop whose dimensions are 0.35 m 0.55 m. The magnetic field has a magnitude of 2.1 T and is inclined at an angle of 50° with respect to the normal to the plane of the loop. (a) If the magnetic...

Hi, I have two questions about permanent magnets: 1. How do you calculate the work done by a permanent magnet on, say, an iron plate? 2. I am aware that the force exerted on an object by a magnet depends on the surface area. Is it also affected by the thickness of the object to a...

Does anyone know if its commericially possible to get a 1-2T electromagnet (no superconductors) but one that's very small i.e. no wider than 2 cm and no taller than 1 cm (with the field in z)? It seems doubtful but I'm not sure where to look, google isn't helping much.

1.If the tube of a faulty barometer is pushed down into the mercury trough, the barometric height will further decrease. Why does this happen? 2. If I am provided with two similar bars, one is a magnet and the other is soft iron. How can I distinguish between them without using any other thing?

hey how would I go about calculating the B field of a bar magnet? I've already managed to calculate the electric field between two charged particles etc and draw that, but I just can't see where to start with this one as its not just a point at north and south but a whole load of atoms...

I'm stuck with Lenz's law, and questions involcing magnet/electromagnet theory such as: The diagram shows a bar magnet falling through an aluminum pipe. Electric currents are induced in the pipe immediately above and below the falling magnet. In which direction do these currents flow...

Ive always wondered what happens to the magnetic field of a bar magnet if it is spun at a high velocity around an axis between the poles. Can someone explain.:smile:

I was surprised not to find a question about this from before, but the question is simply; does a "normal" refrigerator magnet wear out? Will it eventually loose its power and fall to the floor...?

Can anyone help me determine how much force is created when a one tesla permanent magnet is allowed to make contact with a flat piece of iron. The distance that this size magnet can be released and will be drawn to the iron is about 3 centimeters. Is there any way to express this force in joules...

Hi, I want to graph the mechanical force and the electrical force generated by moving a ferromagnetic object into a magnetic field at varying velocities. So, the X axis of my graph would be velocity and Y the two forces plotted separately. My math sucks and my physics is not a lot...