Magnetic fields Definition and 644 Threads

So let's say a water molecule is stuck between a positive magnetic field and a negative magnetic field ?

I don't feel like this is a homework question, more like a curiosity question. If I'm wrong then feel free to move it to the homework section and my apologies. I know how the RHR works for magnetic forces and I can apply it with no problem, however I'm not a physics major so maybe I'm missing...

Homework Statement http://i.imgur.com/mgIkS.png Two long parallel wires carry currents of 2.03 A and 8.83 A. The magnitude of the force per unit length acting on each wire is 4.49*10^5 N/m. Find the separation distance of the wires expressed in millimeters. Homework Equations I'm not...

what is magnetic field and ? how it forms ?

I have read that the electric and magnetic fields are always "perpendicular". Is that true? And if so, does that mean the inner product of the two vectors is zero? E_x * B_x + E_y * B_y + E_z * B_z = 0 ? Also, is there any special meaning in electrodynamics to the quantity: | B |^2...

Since a changing current creates a magnetic field, and if there's a wire near by, the magnetic field will induce a current in that wire. What is needed / what does it take to turn that magnetic field into EM radiation such as a radio wave? Or is it purely just the frequency of the current, so...

Homework Statement A beam of photons, originally at rest, is accelerated horizontally between the plates of a parallel-plate capacitor, the potential difference of which is 1000 V and has a separation of 1.0 cm. The particle enters a region wher a uniform magnetic field, B=0.913T (directed out...

Restrictors and capacitors can be put in series or in parallel to amplify their affects. Hydraulic pistons and pumps can be put in series to intensify pressure. Springs can be put in parallel or in series to come up with alternate, combined properties. However, I can't think of a case...

The equation for the force of a magnetic field on a moving charged particle would say no: F = q * v x B, which means the force is always perpendicular to v, and never has a component along v. Thus a magnetic field can't accelerate a particle, only deflect. This is correct, right? If...

I just have a question based on a toroidal conductor. I know that the magnetic field would run in a circle (http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/imgmag/tor.gif). I am wondering if that magnetic field would do anything. For example, if I dropped something charged into there, would...

Hello everyone Ive got myself into a muddle over the forces involved in magnetic fields. I understand that if a current carrying wire is perpendicular to a magnetic field then it will experience a force according to Flemings Left Hand Rule. Now if a wire is to move in the same direction...

Greetings, I see graphs of the amplitude of a photon's fields over time, but no illustrations of the shape of the field at any instant in time. Are the fields confined to planes like they look in the graphs? Or do they extend in three dimensions like the field around a magnet? Thanks

Homework Statement when the switch is closed , describe what will happen to the meter reading, the direction of the current flow, if any, and the magnetic fields produced in the two coils Homework Equations none The Attempt at a Solution the current flow is shown in the pic...

Hi guys, So far I am aware of these rules regarding magnetic fields/direction of current: A compass needle point is attracted to a south pole (or inversely repelled by a north pole). Left hand rule #2: For an electromagnet, point thumb toward north pole, fingers curl in direction of current...

A plasma is when electrons become unbound by their atoms. So does that mean that you can get a different plasma for all different types of atoms (like gold plasma and helium plasma)? Also the electrons are not free as they are bound to the plasma (but not individual neuclei) by the magentic...

Homework Statement see attached. this question is from a test that doesn't allow any calculators and usually makes students solve the problem in 1 minute max. Homework Equations perhaps biot savart is to be used? but I doubt that can be done in the time limit... The Attempt at a...

Homework Statement A 2.50 meter long copper rod has a mass of 0.25 kilograms. A magnetic field of 0.15 Teslas is oriented horizontally from south to north. a.) What is the minimum current in the rod that would allow it to "levitate" in this magnetic field? b.) What is the direction of the...

Homework Statement Why are magnetic forces not always conservative? I came across this question and to my knowledge they are always conservative...can anyone explain why they wouldn't be?

I'm going in circles on units (or perhaps more accurately different unit systems). The two my professor has chosen to work in are Gaussian units and MKSA units. My problem is one of lack of understanding; are the units of measure for electric and magnetic fields in these systems: Gaussian: E...

my query is : The electric and magnetic fields don’t squeeze or stretch then how is Doppler Effect of light possible? In the phenomenon of Doppler Effect, light emitted from a moving source is detected to have different frequency. If this is taken on terms of detecting the no. of waves...

An electron is moving by a wire that is carrying 10 amps of current e-----------------------------> (electrons) 0===============I-->======== (wire) if the electron is moving by the wire at 2.5x10^6 m/s and is .33 m from the wire how do I find these two answers? A) The magnetic field...

An electron is moving through a 0.002T magnetic field as described below. Show the direction the electron will be pushed by the magnetic field, and calculate teh amount of force exerted on the electron if the electron is moving at 3x10^5 m/s here is what the paper looks like x x x x...

Do magnetic field is produced in all the following 3 cases? Case 1: An isolated electron moving linearly with constant velocity in space. Case 2: An electron moving inside a copper conductor linearly(current). case 3: A ball( made up of many molecules, in-turn atoms, in-turn electrons...

let's say we have a square piece of metal and we put this piece in a variable magnetic field, would it get heated? is this the idea of a current? If we have a rotating metal disk (as the case of a saw for instance), and then we put this rotating disk in a constant uniform magnetic field such...

How can a coil of wire help bring the net flux in a changing magnetic field back to zero?

let's say we have a square piece of metal and we put this piece in a variable magnetic field, would it get heated? is this the idea of a current? If we have a rotating metal disk (as the case of a saw for instance), and the we put this rotating disk in a constant uniform magnetic field such...

Homework Statement I am a HS student researching the penetration depths of magnetic fields in conductors. Specifially, I am investigating the exponential decay of eddy currents induced within a conductor in the presence of a rapidly changing magnetic field. I am a bit confused as to why the...

Good night, I'm trying to do a model of the maglev at small scale, but I'm having a lot of problems to levitate and have stability. I have already read Earnshaw theory, but in youtube i see many models working, but when i try do replicate doesn't work. Now i have a rail way with...

Homework Statement 4. A long straight wire lies along the z-axis and carries an 8 A current in the +z direction. Find the magnetic field (magnitude and direction) produced at x=0.4 m, y=0, z=0.3 m by a 0.7 mm segment of wire centered at the origin. Homework Equations dB=(mu/4pi)(I[dL x...

How do I find the direction of these things? The right hand rule only works when I have the current and it's asking for clockwise/counter-clockwise, and the left hand rule only works when I have two of the three: Current, Magnetic Field, and Force. Example...

Homework Statement Consider three straight infinitely long (parallel to each other), equally spaced wires (with distance d), each carrying a current I in the same direction. (a) Calculate the locations where magnetic field is zero. (b) Sketch the magnetic field line pattern. (c) If the...

recently i came to know that the jets of gases from black holes are due to magnetic fields...so in effect does this field overpower the effect of the gravitational pull of the BH?

Homework Statement An electric field points into the page and occupies a circular region of radius 1.0 m. There are no electric charges in the region, but there is a magnetic field forming closed loops pointing clockwise, as shown. The magnetic-field strength 50 cm from the center of the...

hey, does anyone of you know the reissner-nordström metric, if there is a magnetic field instead of the coulomb field of a charged gravitating body? i just need the formula, but i could not find it in the internet, maybe someone here knows it? sorry for my english, but i am german...

I have had a question pop up latley. Can magnetic fields be somehow shaped or manipulated in anyway? Instead of just their regular form of an oval could you direct it to a diffrent shape? Just asking.

Homework Statement Two very long fixed wires cross each other at right angles. They do not touch but are close to each other. Equal currents flow in each wire in the directions shown below. Indicated the locus of points where the net magnetic field is zero. (I2) ^ |...

Homework Statement Hey everyone, I'm studying for a final and have been having difficulty determining induced magnetic field and current direction. I have a document (link below) with 5 sample problems. I answered them all, and put my reasoning for the answers there in italics. Would...

Homework Statement A particle of charge q and mass m starts moving from the origin under the action of an electric field \vec{E}=Eo\hat{i} and magnetic field \vec{B}=Bo\hat{k}. Its velocity at (x,3,0) is 4\hat{i} + 3\hat{j}. What is the value of x? The Attempt at a Solution The force...

What happens when same magnetic poles (i.e., NN or SS) are next to each other for say an hour or more - will the magnetic fields of those magnets become weaker or stronger? What happens when different magnetic poles (i.e., NS or SN) are next to each other for say an hour or more - will the...

The dramatic lines of force of a magnetic field demonstrated by iron filings in so many introductory texts suggests a problem: A magnetic field is never something that has a process of forming; it is always complete with lines of force: it can change, increase, vanish as in an EM field but never...

Hi, To understand the difference between uniform magnetic fields and field gradients would it help to make comparisons between their effects on different particles? The posts on Stern-Gelach shed some light here. For instance, what effect would a homogeneous and an inhomogeneous magnetic field...

Hi, I'm new here but been looking to you guys for solutions for a while now. However, I cannot find the kind of solution on here already, so I thought I'd put it out here. My main problem with physics is always just finding the formulas I need. If you can at least point me in the right...

Electric/magnetic field at point P in presence of dielectric/magnetic material. I want to confirm either the electric field at a point P in space in an \vec E_{ext} field with the presence of a dielectric material is the sum of the \vec E_{ext} and electric field \vec E_{p} from the...

Homework Statement The diagram below shows two circuits: a very long straight wire, and a single loop rectangle of dimensions a and b. The rectangle lies in a plane through the wire and is placed a distance c from the long wire as shown. The long straight wire carries a current of I...

Homework Statement an electron accelerated from rest through potential difference V1=0.868 kV enters the gap between two parallel plates having separation d = 21.9 mm and potential difference V2= 91.2 V. The lower plate is at the lower potential. Neglect fringing and assume that the electron's...

I am a self taught physics enthusiast with a frustrating conceptual problem; I have been unable to come up with a reasonable visual model connecting electric and magnetic fields. I first began visualizing electric fields as a spherical wave that expands into 3D space. This made since because...

Hi, So this question might be a little simple, or not. But I was wondering about the exact nature of magnetic fields. Now obviously magnetic fields work in a vacuum(due to the fact that it's not a perfect vacuum), but would a magnetic field exist in a theoretical perfect vacuum? Now I think...

Hi, I am wondering if anyone here has heard of or can explain this variation of the right hand rule: Most websites i see tells you to point thumb in direction of current and curl the fingers, and the direction of the magnetic field is the direction you're curling. But my professor uses a weird...

HI all, I have been trying to calculate the displacement of an electron when subjected electric and magnetic field, please see the pic below: I anticipate that the electron will form an ellipse shape. Basically I would like to know how to calculate the major and minor axis of the ellipse...

Homework Statement An electron, initially at rest, is accelerated through a potential diff of 15.0 kv. It is then allowed to circulate at right angles to a uniform magnetic field of strength 2.35 T. Calculate the electrons final speed before entering the magnetic field. Homework...