Magnetic fields Definition and 644 Threads

The title says it all. I've heard my professor saying that they are not conservative. I'm very surprised by this. If it is true then I'll think about all the implications it generates. By the way today was the class where we were introduced magnetic fields for the first time. Thanks!

Two infinitely long straight wires lie in the same plane and carry the currents depicted in Figure P.48. (a) Find the magnetic field at the point P located 24 cm from the intersection of the wires along the bisector of the acute angle between them. (b) Find the magnetic field at the point S...

Ok, so i was browsing around wiki and read about something called a magnetar, which is a very dense neutron star producing magnetic fields in the order of 10 gigatesla. According to the write up, photons split up readily into 2 or more photons. now i know the most powerful magnets we have...

I have been trying to do some research, but the more I search, the more confused I get (praise physics for that one). In anycase, I know that a charge moving through a magnetic field creates a current, so let's say we have an initially charged loop moving through a quasi-uniform magnetic field...

Hello all, doing some reasoning and subsequent Gadenkin experiments, followed by a Non-scientific experiment results in some interesting changes in magnetic fields using glass lenses. Here it is, and please help me to explain this phenomenon, as I can find no mention of it anywhere. Two bar...

Homework Statement Hi, My professor offered the following question: Is it possible to have an electromagnetic field that appears as a purely electric field in one inertial frame and as a purely magnetic field in some other inertial frame? Homework Equations The Attempt at a...

It is my understanding that for all of spectrum of light Electric and Magnetic fields have the same phase. And both fields have correlation - Magnetic fields amplitude grows along with Electric one. I am wandering - is it possible to generate light with phase shift between fields ?

I understand three-phase motors and how the phase offset could produce a rotating magnetic field and a torque. But what about single-phase induction motors? I don't understand how they would be constructed at all. I know that a single-phase induction motor won't self start, but I don't know how...

I'm trying to find out which logical statement is true. If and only if there is a region of space where there is no current, there cannot be a magnetic field that is both unidirectional and nonuniform. Or if there is a region of space where there is no current, there cannot be a...

Homework Statement Two small charges 6e-5 and -2e-5 C. are placed 0.36m apart. Calculate the following: e) the point at which the magnitude of the electric field is zero. Homework Equations EF (field) = (k q) / r^2 where EF = 0 k = 9e9 The Attempt at a Solution I...

What does the magnetic field around a moving charge look like?

Homework Statement http://s619.photobucket.com/albums/tt272/babyazureyoshi/?action=view&current=014.jpg Homework Equations 1) B_x = (µ_0 * I) / 2R at x = 0 The Attempt at a Solution I know that segments BC and DA do not contribute to the magnetic field at O so all I need to know is...

Homework Statement The ion source is a spectrometer produces both singly and doubly ionized species, X+ and X2+. The difference in mass between these species is too small to be detected. Both species are accelerated through the same electric potential difference, and both experience the...

some Fusion power experimental reactors use tokamaks to contain plasma using strong magnetic fields. However this plasma is at a sizzling 1M Kelvin so how is this level of thermal insulation engineered, using magnetic fields?

I recall the non uniform distribution of magnetic fields is the reason sun spots occur. Why are sun spots more predominant about the equator as well?

Hi I've been revising and came across some questions which I do not understand how they obtained the answer could you guys help? 1. Show that the momentum, p, of a particle of mass m is related to its kinetic energy, KE by the relationship p^2 = 2m KE Use the above relationship to...

1. The problem statement Is the magnetic field around the following two bar magnets: |N S| + |S N| the same as the magnetic field around: |S N| + |N S|? 2. The attempt at a solution Yes, but the arrows on the lines move in opposite directions?

Hi, I have 2 extremely hard questions. Any help would be appreciated so much! :) 1. Starting from a speed of 0 m/s, a proton is accelerated through a potential difference of 32000 V. What is the proton's velocity? 2. Is there a formula that I should use to solve for this problem? 3...

Homework Statement Calculate the magnitude of the magnetic field at a point midway between two long, parallel wires that are 1.0m apart and have currents if 10A and 20A, respectively, if the currents are a) in opposite directions, and b) in the same direction. Homework Equations µ =...

I'm interested in doing a project that involves submerging a very strong if not supercooled electromagnet in water; I'm concerned about the effect of the EM field on the water itself. I know a bit about Magneto Hydro Dynamics but i don't have the math skills to understand it entirely. college...

Homework Statement Two co-axial, parallel, circular wires of radius R each carrying current I are placed a distance 2d apart. Find an expression for magnetic field B on the axis at distance e from the midpoint between the two loops up to and including terms of 0(e3). Homework Equations...

I'm wondering about general magnetic forces, specifically the behavior of unmagnetized ferromagnetic materials in a magnetic field. I.e., a simple bar or electromagnet picking up an unmagnetized piece of iron. Are there formulas to explain this behavior? The lorenz force equations by...

I was told that if you put a spin 1/2 particle in a magnetic field, it will align with or against the field. But some places it also says that it will precess around the field. Which one is right?

Hi forum, I know it's an odd topic header, but please bear with me, especially as I'm a newbie here and useless at Physics. I felt this would be the best place to look for advice and understanding on magnetic fields. I ask as I am a wrist watch fan...and since the release of a Rolex...

Behaviour of LEDs in presence of magnetic fields?? How do LEDs behave in presence of magnetic field?? Any good books or papers dealing extensively with this?? thanking in advance..

what are electric and magnetic fields? i know that theyre constant exchanges of virtual photons but what properties do each have and what's an example of a change of perspective where an electric field becomes a magnetic field and/or vice versa

I know that \int_{S}^{}\int_{}^{}\vec{B}\cdot d\vec{A} = 0 because \textbf {div} \vec{B}=0 IE, because \Phi_{B} leaving a closed surface must equal \Phi_{B} entering. Yet how is it then that \int_{C}^{}\vec{B}\cdot d\vec{l} isn't also equal to zero? Shouldn't it be true for any...

Hi, I'm looking at question #33 of the linked book on page 391. http://books.google.ca/books?id=4fXFO-0B6f4C&pg=PA391&lpg=PA391&dq=zero+magnetic+fields+proof&source=bl&ots=ZmVev2Wdpb&sig=_P2-p3xN29sgIKC3aNsp8N15xCo&hl=en&ei=ExrUSaukIIWsnAfRteDzDg&sa=X&oi=book_result&ct=result&resnum=1 I...

ok guys so i have two questions, i need help on two questions on the following site "[URL /AP%20Physics%20Daily%20Problems/AP%20Daily%20Prob%20131-140.pdf"]http://staff.hartdistrict.org/glyle/ap_physics/Homework /AP%20Physics%20Daily%20Problems/AP%20Daily%20Prob%20131-140.pdf[/URL] they...

Homework Statement A long, straight wire carries a current of 14 A. Next to the wire is a square loop with sides 1.0m in length. The loop carries a current of 2.5A in the same direction as the wire. Calculate the net force acting on the wire. Homework Equations Magnetic Field for...

1. I have read that external magnetic fields cannot penetrate a superconductor. Why is this? 2. Does the magnetic field produced by the superconducting current extend outside of the superconductor? And if so, what happens when the magnetic field starts to collapse, can it renter the...

Since neutrons have no electric charge, how is it that a neutron star is able to produce a magnetic field? :confused:

Homework Statement An electron is moving through a magnetic field whose magnitude is 8.70 X 10-4 T. The electron experiances only a magnetic force and has an acceleration of magnitude 3.50 X 1014 m/s2. At a certain instant, it has a speed of 6.80 X 106 m/s. Determine the angle \theta (less...

Homework Statement Your friend wants to be a magician and intends to use Earth's magnetic field to suspend a current-carrying wire above the stage. He asks you to estimate the minimum current needed to suspend the wore just above Earth's surface at the equator (where the Earth's magnetic field...

I have a physics exam tomorrow and while recapping things for the exam, I was wondering one thing. The magnetic force exerted to a current carrying wire in a uniform magnetic field is \vec{F}=I \vec{l} \times \vec{B}. But a current carrying wire induces a magnetic field, so the magnetic field...

Homework Statement The drawing shows a parallel plate capacitor that is moving with a speed of 31 m/s through a 4.0 T magnetic field. The velocity v is perpendicular to the magnetic field. The electric field within the capacitor has a value of 170 N/C and each plate has an area of 7.5...

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

Alright. I don't understand the fundamental quantum basis behind the attraction of two magnets. My book notes that magnets manifest themselves when a material such as iron has unpaired electrons in orbitals that spin in the same direction. If an electron is paired, the electrons will spin in...

Homework Statement http://www.aijaa.com/img/b/00125/3627010.jpg http://www.aijaa.com/img/b/00758/3627011.jpg Homework Equations E_k=\frac{1}{2}mv^2 \vec{F}=m\frac{\vec{v}^2}{r} \vec{F}=q\vec{v} \times \vec{B} \frac{v}{r}=\frac{2\pi}{T}=\omega The Attempt at a Solution The...

Homework Statement A beam of protons is accelerated to a speed of 5.0x10^6 m/s in a particle accelerator into a uniform magnetic field. What B field perpendicular to the velocity of the proton would cancel the force of gravity and keep the beam moving exactly horizontally? Homework...

HI all: I have one confused question. a infinitely long wire carrying constant direct current is placed in the space. One particle with charge q and velocity v is moving in the magnetic field which is created by current-carrying wire. We know in the lab frame. particle will accelerate in this...

Can anyone explain why these two field patterns are so similar? The (3,2,1) hydrogen wave function, and this pattern generated from a magnet on a CRT. (attached to post)

When electricity flows through a coil of wire, what does the resultant magnetic field resemble? a the magnetic field of a bar magnet b the magnetic field of a horseshoe magnet c the magnetic field around a straight wire d the magnetic field around a circular magnetic disc. ok so i know...

Homework Statement Two point charges, -520x10-6C and -270x10-6C are 2 meters apart. At which point would a carbon nucleus experience zero net force? (positive test charge) Homework Equations k=9x109 F=k((q1*q2)/r2) Coulomb's Law E=k(q1/r2)=(F/q2) The Attempt at a Solution I really...

Homework Statement I don't quite understand the following question, i get a very unrealistic result... The write head of a hard disc drive produces a magnetic field of 95mT. The disc has a radius of 3.5 inches and rotates at 7200 rpm (rotations per minute). Calculate the Lorentz force...

Homework Statement The problem is as seen in the attachment.Homework Equations T(torque) = (N)(I)(A)(B)(Sin(theta))The Attempt at a Solution For this question I used the above formula to find the magnitude of the torque, but what I am not sure about is which orientation would produce the...

I was wondering if there where any ideas or theories regarding what a magnetic field is composed of. Are there any particle ideas, or is it just something we don't understand yet

I have a simple question here that I seem not to be able to figure out. If you have a regular bar magnet, it emits a magnetic field around it. So, if you create an experiment and found out how far that field reached, you would see that the field doesn't go very far. Maybe like 3 inches (~...

Homework Statement Which two of the three types of fields in the title of this are thread are the most similar? Provide supporting evidence? Homework Equations Gravitational: -Source: point mass -Field intensity proportional to: M/r^2 -Range: long range -Strength: weak -Direction of field...

http://www.sciencedaily.com/releases/2008/12/081202081449.htm ScienceDaily (Dec. 3, 2008) — The sun’s magnetic field may have a significant impact on weather and climatic parameters in Australia and other countries in the northern and southern hemispheres. According to a study in Geographical...