Magnetic field lines Definition and 53 Threads

As stated in the problem, I want to demonstrate mathematically that field line density is directly related to the magnitude of B. How would I be able to do this, other than simply using the flux equation and showing that for a higher flux in the same area, the magnetic field must be rise...

I want to improve the magnetic field strength at the surface of a magnet configuration by utilizing diamagnetic materials to guide the magnetic field lines. I have not the proper equipment to measure the effect myself but would this work? This is the initial configuration with four magnets side...

In the picture below, the direction of the magnetic field lines can be determined by using the right-hand rule with the thumb pointing in the direction of the current. If we use the right hand rule in the picture below, thinking of the yellow arrow as the current, we would not get the correct...

I have an ordinary switchable magnet for holding tools to a lathe. It's like a magnetic force gearbox, but I can't quite understand the force multiplication. When placed on a steel surface the switch force is approximately ~5N on both finger and thumb at 1.5cm radius acting over a 3cm arc...

I'm trying to understand the relationship between the "number" of field lines passing through a region and the magnetic force in this region.I understand that the drawings are of course conceptual: we cannot draw "all" the field lines (although can be visualized with iron fillings).Also the...

I might be a slow learner, but am still trying to understand the difference between field lines and vectors. I've got that magnetic field lines are symbolic and that the directional arrows applied (from north to south) are a convention. But see the attached image. The field lines form a closed...

Greg Bernhardt submitted a new blog post Are Magnetic Field Lines Real? Continue reading the Original Blog Post.

In conducting research into historical accounts of Earths magnetic field, I consistently come across proposals of stable planetary magnetic grid systems; many of these theories which have apparently been developed through much time and effort. While I am unaware of any theory that cannot be...

Hello, I am unable to understand a certain (important) concept. We all know what the field lines of a permanent magnet look like. They go from north to south, and curve around the magnet. This direction (direction of the magnetic field) does NOT describe the direction of a force. And that's...

Is it possible to direct or confine field lines to be shaped like a laser? I know there are magnets such as neodymium cones that direct field lines through the tip but they don't seem to have the amount of pull as I'm looking for. If there isn't, is there anyway to amplify the power? Maybe align...

My physics teacher said that the northern lights are the product of charged particles coming from the sun and interactign with our atmosphere. I believe he said that these are deflected by Earth's magnetic field and directed towards the North and South poles. When I look at pictures on this...

I have a question which puzzled me when I was reading up about auroras. When talking about the interaction of the solar wind and the Earth's magnetic field, the book said that "particles are accelerated along magnetic field lines towards the earth" That didn’t sound quite right, as I was taught...

So i know that magnetic field lines are closed, in an electromagnetc wave how can be these lines closed? i cannot picture this in my head

This question is regarding the magnetic field lines around two abutting alternating poles. Take two axially magnetised disc magnets and place them next to each other (like tangent circles), so on each side the adjacent or neighboring magnet is of the opposite pole. By sprinkling iron filings...

Homework Statement Hey! I have trouble with an exercise that I need help with. Here it is: The magnetic field lines for the average interplanetary magnetic field (IMF) follow Archimedean spirals. i) Find the heliocentric distance r in Astronomical Units (AU), where a field line has wrapped...

Apart from the orientation of a compass needle and the pattern formed by iron filings, what other proof do we have of magnetic field lines forming loops?

Homework Statement The figure shows crossed uniform electric and magnetic fields and, at a certain instant, the velocity vectors of the 10 charged particles listed in the table. (The vectors are not drawn to scale.) The speeds given in the table are either less than or greater than E/B (see...

Magnetic field lines around multipolar magnets get quite complex. There are local field vectors and field gradients in the x, y, & z plane. In the following diagrams I have tried to illustrate field lines around a centrally (half and half) charged disc magnet. The top diagram represents the...

Hi, A potential magnetic field has no curl. According to the "curl theorem" or stokes theorem, a vector field with no curl does not close. Yet, Maxwell's equation tell us we shall not have magnetic monopoles, so the loops have to close... ? What am I missing to remove this apparent paradox of a...

Hey guys, I have a question. I am doing some homework for university and got super confused (probably just messing up things). So in school you learn that magnetic monopols do not exist. But my question is now: On the sun there are coronal holes, region where the magnetic field is not able to...

This is a bit vague, but I remember reading that during stuff like coronal ejections, magnetic field lines "reconnect". Now, does that not suppose "loose" magnet lines in the process? Which to my understanding do not exist?

I have looked in vain on the web for pictures of magnetic field lines for multiple linked current loops. I would be happy just to see a picture of the field lines for a simple Hopf link but somewhere there must be pictures for the Borromean rings and other more complex links - and also braids...

Are magnetic field lines actually lines? To me, they are just a way to pictorially represent the magnetic field, and there are no lines. BUT, whenever you do the experiment with magnetic filings on a piece of paper, they align in actual lines. HELP!

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...

Hi, please could someone explain why the magnetic field is stronger at the poles of a magnet. I know that the field line density is strongest at the poles and more spaced out in the middle. I get that. I just wanted to know why the magnetic field is stronger at the poles than the middle of a...

I need help understanding a certain problem. It basically stated: an airplane accumulated a positive charge, heading westward above the equator. Find the direction of the force (using the lame right hand rule thing). The problem I had was figuring out was whether the magnetic field would hit...

I was looking through a book on magnetism and it had the attached diagrams of field lines and stated that the classical diagram of field lines exiting the N pole and entering the S pole is incorrect. They claim their diagram is the correct representation of the magnetic field lines. Their...

Hello All, I was just checking magnetic field lines as in attached figure. I am curious to see some gaps between adjecent field lines in the figure. Why it is not like a sheath( for example in lighting field) but as lines? Thanx in advance Abraham

I have read in my schoolbook that when a wire of length l moves at velocity v in a magnetic field cutting the flux lines an emf is induced which it is calculated from emf = blv, I understand that emf is induced at time variation of magnetic flux across the wire, but I Can't see any change in the...

I guess this is maybe more of a vector calculus question, but here it goes. Say I have an arbitrary current distribution \vec{J} with the corresponding magnetic field given by \vec{\nabla}\times\vec{H} = \vec{J} \vec{\nabla}\cdot\vec{H} = 0 What is the best way to calculate the field/flow...

Hello. Assume an electron gun, as in CRT, made of plumbing copper instead of glass. Using magnetic scanning coils to move electron beam. Will the displacements of this beam be linear as if tube material was made of glass ? PS : this is not an exercise by though but a real problem I encounter in...

I see textbooks assign directions to magnetic field lines, for example north poles extending outward and south flowing inward. Are these directions correct or just a way to help tie the concept together and have just been arbitrarily picked much in the same way as conventional current?

The lines of flux of the magnet possesses the following properties: 1)Forms closed loop 2)Starts from N-pole and closes at S-pole 3)Do not intersect each other 4)Parallel line and same direction repels each other 5)Parallel line and opposite direction attract each other So...

Hi, I was wondering - In the plots that we see of magnetic lines of force (like this one) what exactly are they plotting against what? Meaning is it Bx vs x vs y, or is it Bx vs By vs Bz?

When people talk about sunspots and the solar cycle and stuff like that, they often mention magnetic field lines poking through the surface of the sun. I'm pretty sure I get why the magnetic field lines would be twisted up by the non-uniform rotation of the sun, and why they would poke out of...

It might seem trivial for most of you but i am confused by the definition of direction of magnetic lines. It's well known the magnetic field is directed from S to N but if one looks from outside and follows the magnetic line then one come from N to S. I am aware of that magnetic lines are closed...

I wanted to ask that do each point of the current-carrying circular loop would create a magnetic field and hence the magnetic field lines? And if yes wouldn't the field lines produced by each point of the loop would intersect each other? I read somewhere that magnetic field lines never...

Curious as to whether there's a formula for calculating the shape of the magnetic field lines, including electro magnets (solenoids). I want to create a 3D graphical display for the magnetic field lines of magnets.

Now this might seem like a really stupid question but I'm just a high school student so please bear with me. I've been studying about magnetic fields and my teacher says (everyone does in fact) that in a magnetic field, the magnetic field lines start from the north pole and end in the south...

Suppose that a function B:\mathbb{R}^n\to\mathbb{R}^n and c:\mathbb{R}\to\mathbb{R}^n are defined such that c is differentiable, and \dot{c}(t) = B(c(t)) for all t. The question is that what must be assumed of B, so that it would become possible to prove that c(T)=c(0) with some T\neq 0?

I have seen people write that there are no such things as "field lines", but that the magnetic field is a continuum. But iron filings on a paper over a magnet will arrange on lines of the magnet's field...Is this an illusion, or are there "lines" that make up the field?...thank you

untruncated version of question: As electrons move through a wire, is the direction of the curl of the magnetic field lines observed derivable from an underlying property? =========================== more detail (only to further clarify my question as useful): > looking for a mechanistic...

How does computer software plot magnetic field lines where the density of lines represent flux density? How does the software know which points to start plotting from in order to come out with a true representation?

How can magnetic field lines "snap"? In astronomy, magnetic field lines around stars or planets are sometimes said to "snap" and release their stored energy. e.g. the aurora borealis is created that way http://www.atoptics.co.uk/highsky/auror2.htm Also gamma ray bursts of neutron stars...

A moving electron's magnetic field lines. How do the magnetic field lines of a moving electron in a straight line look? What about the magnetic field lines of a rotating hydrogen electron? I mean the magnetic field produced due to the electron's intrinsic spin and due to its movement in a line...

The magnetic field surrounding a bar-magnet (for example) is continuous. The lines that are drawn to depict the strength and direction of the field don't actually exist. They are akin to drawing contours on an OS map, are they not? What therefore explains the behaviour of iron filings when...

Is it possible for magnetic field lines to be broken?

Homework Statement A wire carrying 15 A of current has a length of 17 cm in a magnetic field of 0.80 T. The force on a current-carrying wire in a uniform magnetic field can be found using the equation F = BIL sin θ. Find the force on the wire for each of the following angles between the wire...

Homework Statement Two of the MHD equations can be formulated as \vec{E} + \vec{v} \times \vec{B} = \eta \vec{J} \nabla \times \vec{B} = \mu_0 \vec{J} where [itex]\eta[/tex] is the resistivity of the plasma. a.) Derive an equation for the magnetic field at very high resistivity and...

Magnetic Field Lines Question http://img101.imageshack.us/img101/9819/coil2sm.jpg Could someone tell me which is the direction of these magnetic field lines and why?