Magnet Definition and 912 Threads

Is there a material that blocks or reflects magnetic fields such as a field from a neodymium magnet?

I received an assignment from my professor which sounds like follow: "Suggest a motor which operates only on magnets and gravitational force." While I did make a search online and found some model which seems to work, I am sill a little skeptical (There are videos online, but none of them...

Is there a way of calculating how much force can be applied to an object if you are given the magnetic field strength of an electromagnetic? For example, if an electromagnet produces a B field of 4T, what is the maximum mass of iron it can hold? And also, how does one calculate the...

Hello, I'm a mechanical engineering student currently working on a project which involves a compressed air motor and a Permanent magnet DC generator. I have this generator : http://www.windstreampower.com/443905_PMDCG.php Basically, we'll use the generator power output to determine the...

I'm looking for an equation to calculate Tesla (B) between two permanent magnets with distance of 10mm. Magnets are located in front of each other; disk shape and intensity of each is 1.3T in its core, and 0.6T on surface, so I'm interested how to calculate the B between them in distance of...

I have ordered a spool of wire with these properties: NEMA-MW-80 155C This magnet wire has a copper core with a dual film of polyurethane (85-90 percent) with polyamide(nylon) as an outer coating making up the other 10-15 percent. .0169 inch diameter rated to 155 degrees centigrade...

G'day. I was wondering about the possibilities of making a permanent magnet hoverboard that levitates above a permanent magnet floor. They say that these new neodymium magnets can attract hundreds of kilos/pounds. Since repulsion and attraction forces are the same magnitude from what I hear, why...

I need to calculate how much voltage is created as a magnet passes over a coil. However I don't know a formula to calculate this. Could anyone help me, I just need a formula PS: sorry, spell check does not work

I was wondering if it was possible to bend a beam of light with a magnet. If this is possible could someone tell me what the requirements for the magnet be to do such a thing.

I used the formula here: http://en.wikipedia.org/wiki/Magnet#Force_between_two_bar_magnets The values came from an experiment in which I found the force between two small Neodymium magnets by balancing with the force of gravity (it was around .15 Newtons). Am I using this equation...

I have been doing some experimenting with a relatively short cylindrical permanent magnet and a solenoid with DC current applied. I would like an explanation as to why these two things happen. The OD of the cylindrical magnet is just a little bit smaller then the ID of the solenoid. Placing...

I have a cylindrical neodymium magnet. I know that the magnetic field varies with distance, but how would I determine the magnetic field B at a certain point, through experimentation? I know how to find the force between two magnets at different distances by balancing out with gravity, but I'm...

I would like to know..what is the concept of rotating a magnet above a coil of wires to produce electricity.. what is the factor affects the power of electricity produce.. 1)Is it the number of coil? 2)is it the power of magnet? 3)is it the distance between magnet and coil 4)or anything...

I've been building an electromagnetic wheel (a bike wheel which rotates by electromagnetic interaction between electromagnets on the hub and permanent magnets on the rim) and I've come across an interesting problem. Currently, I've got the electromagnets mounted on the hub with the coils pointed...

To my surprise, through experimentation, I have found that the "Flux tubes"/lines of force, do not move when the magnet is turned on its' axis but the field lines do move with the magnet when one flips it from N to S. This would lead me to conclude that the N/S area are a property of the poles...

1. is insulated wire ok to use on an electromagnet? 2. say you have an electro magnet in the form of a spool of wire with an iron core, would it be possible to wrap the entire assembly in a material that would contain the magnetic field produced by the current flow? 3. what is the strongest...

Does anybody know of an online application, or a program, or anything that can simulate accurately magnets and how they interact? Like a simulator. Thanks very much. ^_^\/

If I get this whole “Moving magnet and conductor problem” business at all, one frame’s electricity is another frame’s EM wave. So moving a magnet causes an electromagnetic wave, AKA: photon. I assume the faster you move it, the higher the energy of that wave/photon. (Maybe you have to vibrate it...

Homework Statement For a magnet of length l = 16 cm, cross-section .25 cm^2, and magnetization M = 7.8x10^5 A/m, estimate H and B at the midpoint.Homework Equations Unsure if any of these equations are relevant, but these are the ones that I've tried. q_m = MA B = \mu_0 M \mu_0 H = \mu_0 MThe...

hi..i know the faraday's electromagnetic induction e=-dФ/dt...supposing there is an coil of wire and i am accelerating magnet through the coil of wire and this will produce emf because accelerating magnet results in change in magnetic field...my question is how to relate this acceleration a and...

Hello, please forgive my ignorance. I need help coming up with a formula I can't seem to find on the internet. Assume I have a magnet that can attract a maximum of 5kg iron sphere against gravity from a distance .2m. My question is how much could that same magnet attract at a distance of .1m...

Homework Statement A coil of radious 4cm has its plane perpendictular to a uniform magnetic field of strenght 2 mT directed into the page as in the following diagram http://i83.photobucket.com/albums/j283/cowsgomoo47/physics_prob_magnetism.jpg The magnetic field is then switched off is...

Homework Statement How do I calculate the magnetic field of an irregularly shaped permanent magnet? Homework Equations Field of a magnetic point dipole: \vec{B}(\vec{m},\vec{r}) = \frac{(\vec{m}.\vec{r})\vec{r}-\vec{m}\left\|\vec{r}\right\|^{2}}{\left\|\vec{r}\right\|^{5}} where \vec{m}...

Ok so, i think this is kinda a basic question but here goes. I am building a machine that uses magnets and desperately need to eliminate a zero point so the movement will be smooth so what i need to know is if you have a magnet being attracted to substance Q and the magnet has a 3cm distance...

please tell the name of a liquid (at room temperature) which is attracted by a magnet. and its constituents does not get seperated.

Homework Statement The sketches below show a circular coil and a permanent magnet; the arrows indicate both the magnitude and the direction of the velocities of the magnet and coil. In which situations will the induced voltage (and hence the current) in the loop be zero? (Enter your answer...

I was watching this video on youtube called will it blend where they supposedly blended neodymium magnets into powder. I saw sparks coming from the process of it being powdered but I have read elsewhere that trying to file neodymium magnets is dangerous as it would be explosive. I am not sure...

would like to ask, is that possible to generate electricity without using available electric and magnet? is that if we don't have magnet, we wouldn't have electricity? could the positive or negative field be gathered without using the magnet?

Any one know? I think becayse when you rub the magnet over the metal it causes something to align up, aligning up the poles? Ah i duno

if the Earth is one big magnet, why there is not current induced in our selfs? I mean, why there is not electromagnetic induction in the human body?

I want know that lifting magnets for lifting a lots of cars ; so it use energy or not? Why a lifting magnet use energy? It can only have a static force with his superconductor ! Why that superconductor use energy(electricity) for his static force? virtualempire.com/banners/vebtn3.gif

Wind power is a force of nature and it has been used for centuries like for Dutch Windmills. Permanet magnets are a force of nature which through innovation have now been produced so well that they can now hold up to 500 times their own weight. That is a lot of power. The only...

Permanent magnets are advertised as having some scalar strength, say, 1.5 Teslas, depending on the composition of the magnet but not its volume. I'm confused about what this means. Shouldn't the magnitude of the magnetic field vary depending on where you measure it? And if I epoxy together two...

hi there , When a North Pole of a magnet is made to oscillate in the direction of Earth's North Pole magnetic field. Also When a south pole of a magnet is made to oscillate in the direction of Earth's north pole magnetic field . I then measure both of there period of oscillation When doing...

i29.tinypic.com/25ppfth.jpg Can we build it without any inequality and without any jagged ? i want all flux work as well as picture can we build this radially oriented magnet?

Hello, (I'm not fluently in english, sorry if it's not a pure english) I use FEMM software for caculate energy. I have found an integral fonction "Magnetic field Energy" when I select a surface. But I have always the same energy, I don't know why. Is there necessary to make something...

Why an electro magnet use energy? the resistance is reason ?

Magnet near a "magnetic" black hole Hi, If I were to bring a magnet (just 1 mm long) close to a hypothetical "magnetic" black hole - something that has such an incredibly high permeability that it draws all the magnetic field lines from the magnet's pole toward it - and if this latter object...

Homework Statement A bar magnet experiences a torque of magnitude 0.075 Nm when it is perpendicular to a 0.50 T external magnetic field. What is the strength of the bar magnet's on-axis magnetic field at a point 20 cm from the center of the magnet? Homework Equations \tau = \vec{\mu} B...

Homework Statement A copper penny falls on a path that takes it between the poles of a magnet. Does it hit the ground going faster, slower, or at the same speed. The Attempt at a Solution Clearly the penny undergoes a change in magnetic flux. Since it receives a change in magnetic flux...

The strength of magnetic force varies inversely with the square of the distance between the magnets. In other words, Force = k/(distance^2) Suppose that when two magnets are 4 cm apart, there is a force of 4 Newtons. Find the work required to move the magnets from a distance of 3 cm apart...

Can anyone check if I answered these questions correctly? Thanks a bunch! 1. The N pole of a bar magnet is pointed in along the axis of a horizontal, continuous coil of wire. When the magnet is quickly roated about a vertical axis until the opposite end of the madnet points into the coil...

Hi, I have 18-awg enamel magnet wire and I was wondering what the maximum current I should use is such wire is. Thank you.

Magnetometer is used to compute the magentic moment of a magnet. In this procedure, we are asked to record the angles of deflection on both sides of the compass heads (that is North and South poles of the compass), since they are vertically opposite angles, they should read the same. Why are...

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...