Magnetic fields Definition and 644 Threads

a simple idea. Maxwell’s theory of magnetic fields says there is two components ,an electrical field and a magnetic field. (put simply). I have an idea to pick up radio waves using a magnetic beam. rather than the normal dipole set-up, just wondering if you think this idea is possible to make...

Homework Statement What is the magnitude of the magnetic field inside the solenoid at t = 1 ms? Homework Equations Not sure The Attempt at a Solution Well I would make an attempt but firstly I have a question. What I want to know is the above question simply referring to the emf of the...

Field of what exactly? Sounds is vibrations in air molecules. Electromagnetic waves are vibrations in fields of what? Where are these fields existing? Wiki states that fields are "A field is a physical quantity that has a value for each point in space and time." Where is the physical...

I am meeting a professor this week to see if I can work in his lab. His area of research is magnetism. In a preliminary meeting, he told me that the 'ambient' magnetic field in the lab is about twice the magnetic field of the earth. I spent about 10 minutes in the lab. There was a machine with...

1. I have heard that if you take 4 batteries and 2 non-coated wires, and run the wires + to -, with current flowing in opposing directions, with the wires in close proximity, that a magnetic field will be created between the 2 wires. Is this true? 2. Since photons have no charge, is there...

Homework Statement The below region of space shown has uniform electric and/or magnetic fields, dependent on the conditions listed for cases A-G. Identical positively charged particles enters these regions with the same velocity. Rank the magnitude of the force on the particle just after it...

Homework Statement [/B] Charged particles with equal mass and identical initial velocities move through regions of space that may have magnetic fields. Rank the magnetic field in each case from greatest to least. For this question, fields out of the page will have positive values, while fields...

Homework Statement A magnetic field of 1.4 T [N] is 4.0 m wide. A very long wire crosses the field. a) If the current in the wire is 2.0 A [W]. find the magnetic force on the wire. Create a diagram. b) What will happen to the force on the wire if... i. The wire is rotated slightly in the...

Homework Statement Two charged particles (P & Q) are fired into a uniform magnetic field that is directed into the page. When a particle possessing charge q moved through a magnetic field B at a velocity v it experienced the lorentz force that has a magnitude of F=qvB. What is the sign of P...

I've been told that magnetic field does not mask or influence any GHz transmissions; TV, Radio, Wi-Fi, etc. and should not pose a problem. Can someone explain why they do not interact? Credible documentation such a law or theory? Educational documentation? Thanks in advance.

If we put cathode rod with enormouse voltage in vacuum between strong magnetic fields pointing down parallel to rod end then put electron in it with initial speed equal to speed of light and begin circling around cathode, Will electron make gamma -rays according to synchrotron radiation?

According to page 61 'Einstein' by Andrew Robinson an electric charge at rest produces no magnetic field. But: For an observer moving East with uniform motion the charge will appear to be moving West uniformly and B, using a sensitive compass, will detect a magnetic field around the 'moving'...

I should add context to this question that what I know so far of the emf is that it is defined as ##\mathscr E=\oint f \cdot d\ell## where ##f## is the sum of the forces on the charges. In the textbook I'm reading it gives an example of where a person pulls a rectangular wire with a velocity...

Why are electric and magnetic fields in an electromagnetic wave in phase? Can somebody please explain that?

i am having some trouble with understanding the magnetic fields inside transformers and how they relate to back emf. In particular, I am considering the two cases of current passing through the primary coil but not the secondary coil, and then with the secondary coil as part of a complete...

Homework Statement Copy the diagrams in Figure 7 into your notebook, and draw the direction of the conventional current or the magnetic field lines. Also indicate the location of the north and south poles where appropriate. FIGURE 1 FIGURE 2 Homework EquationsThe Attempt at a Solution Using...

Homework Statement A cathode-ray tube aims electrons parallel to a nearby wire that carries current in the same direction. What will happen to the cathode rays in terms of deflection? The Attempt at a Solution [/B]The Motor force deflects the cathode rays ?

Homework Statement Two parallel conductors each carry 10 A of current in the same direction. a) What is the magnetic field strength at the midpoint between these wires? (answer = 0T) b) What is the field strength at the same point if the current ran in opposite directions? (answer = 4.0x10^-4T)...

Homework Statement There is a sphere of magnetic material in a uniform magnetic field \vec H_0=H_0\vec a_z, and after some calculations I got the magnetic moment vector \vec M_0=M_0\vec a_z, where M_0 is something that isn't important to my question. I am unsure if this magnetic moment vector...

When a moving proton travels through a magnetic field, doe's it's magnetic field (that it's giving off) naturally align with the outside magnetic field (due to a magnet or something in the environment)?

Homework Statement An infinite cylindrical wire of radius ##R## carries a current per unit area ##\vec{J}## which varies with the distance from the axis as ##J(s)=ks^2\hat{z}## for ##0<s<R## and zero otherwise where k is a constant. Find the magnetic field ##\vec{B(s)}## in all space. Homework...

Hello, I've been stuck on this question for a few hours and I hope someone can help. Here is the question: "Consider two materials bismuth and aluminum with χ m = −20 ×10−5 and χ m = 2 ×10−5, respectively. Find the magnetization vector and the magnetic field in these materials when they are...

I have some questions.

So there was this article published today that some researchers may have found a dark matter signature emanating from the sun in the form of xr-ray emission from axion interactions with Earth's magnetic field. Article...

Hello. I'm looking to build a strong electro magnet with ac power. I was going to use a MOT transformer so the primary was going to be the same windings. For the secondary windings though I'm trying to decide if I want to go with a higher current or voltage. I would assume that a stronger...

Comets have what is called an "induced magnetosphere". Has anyone been able to document polarity in any of the observed comets magnetic fields yet ? If they have I'm curious how it relates to the orbital plane of the comet. I haven't been able to locate that info if it exists so just...

I am wondering if it is possible to shield strong (1 Tesla) DC magnetic fields with high attenuation factor (10^4 or better) WITHOUT also shielding AC magnetic fields above frequencies of ~10kHz. I have looked at mu-metal, which as far as I can tell shields DC but also AC fields to some...

Help required to understand the physics concepts What will be produced if mutual induction of electric and magnetic fields occurs? Thanks

E = - grad*phi - 1/c (dA/dt). phi is the scalar potential, and is given. How do I calculate the vector potential = A ? Is it A = (v/c) * phi ? If it is, then where is this equation coming from? Thank you.

Hello, I am having to find the rotational diffusion of a magnetic particle inside of water. I already have a diffusion coefficient but I do not know how to take into account the restoring force that the particle will feel from the magnetic field. The info that I know is: B-Field Strength...

Apologize in advance for the long post! We are in this particular situation and, being a novice with electrical- related issues, would greatly appreciate opinions here. After a year long search, we found this nice home in Texas meeting all requirements my wife and I were looking for, and at...

Hi this is my first thread since joining the website, so let me know if I am violating any rules here. I read a bunch of rules to follow in the website but don't think I can remember everything. I am reading chapter 18 on Feynman's Lectures on Physics volume 2 (electromagnetism). It talks...

Homework Statement Does the number of attached identical magnets linearly relate to the number of paper clips/bolts/nuts that are magnetically chained together? Homework Equations I have no idea. The Attempt at a Solution Yes they are linearly related? I am guessing that yes it...

Hi, I am a year 12 student and I have some some questions about magnetic fields. Homework Statement Do all magnetic fields (in particular ones produced by electromagnets) have distinct poles? How does a force act an object carrying current under presence of a magnetic field. Homework...

Hi, I've read that the speed of em waves in the vacuum is the electric field component frac the magnetic field component, why and how can this be explained more easily ? Thanks

Hi, I am having a question about diamagnetism. I understand that ferromagnets realign with external magnetic fields. I know that besides diamagnets like copper, bismuth, that all matter exhibit some diamagnetism to some degree. I wonder though if these paired electron filled orbits of...

Capacitors are popular candidates for explaining electric fields. The phenomenon becomes really apparent with the aid of a leiden jar ...which is really just a capacitor. Anyways, as long as you're cranking the handle on the electrostatic machine, the charge is going to build and build until I...

Electric fields vs magnetic fields? Ok, so in class last week, I had asked my professor about using the Lorentz Force Law to solve a particular problem. When he responded with "we only have a magnetic force from the current in the wire, so we don't have to worry about an electric field," that...

I'm currently taking Physics II and had a question. I'd ask my professor, but he's out of town until Monday and this is driving me crazy. Anyway, we recently started learning about magnetic fields. So far, I'm grasping most of it no problem. One thing that is throwing me off though is how...

Greetings, PF forum members! I have had a sudden interest in Active Radiation Shielding (ARS), and as such, an increased interest in magnetics. I have had trouble locating any information regarding the possibility/impossibility of altering magnetic fields in such a way that changes the field's...

Homework Statement An ink drop with charge q = 3 ✕ 10-9 C is moving in a region containing both an electric field and a magnetic field. The strength of the electric field is 8E5 N/C and the strength of the magnetic field is 1.3 T. At what speed must the particle be moving perpendicular to...

Problem: You can make an electromagnet by wrapping wire around a wire and connecting the ends to a battery. If the battery is connected so that current wraps up in the front and down in the back, which direction will the magnetic field of the nail point? Answer: the magnetic field of the nail...

Hi guys! So I just need help in one tiny thing. Does anyone know a good book that can thoroughly explain physically and mathematically diamagnetism in plasmas within magnetic fields? I would really appreciate the help guys! Also, I am very much familiar with vector calculus (also tensor calculus...

Do moving charges 'create' or 'induce' magnetic field around them? I believe that induction is a phenomenon in which the behavior of one object depends on the behavior of another object provided they interact with each other. In this case, the moving charge is just surrounded by air or vacuum...

I have an enigmatic problem that I cannot explain. I have on video the results of this experiment at particular location where I believe bio-electromagnetic weapons testing is occurring. Does anyone have theories of why the following occurs? I have several sized physical compasses that...

Homework Statement Consider a region of space containing static free charge density ρ(r) and current density j(r). What two physical laws determine the electric and magnetic field in this region? State the integral form of each law, showing the explicit dependence of each on ρ(r) and j(r)...

Homework Statement The unit of magnetic flux is named for Wilhelm Weber. A practical-size unit of magnetic field is named for Johann Karl Friedrich Gauss. Along with their individual accomplishments, Weber and Gauss built a telegraph in 1833 that consisted of a battery and switch, at one end...

Homework Statement The diagram shows the magnetic field between like magnetic poles Homework Equations Point C is the exact middle of the region between the poles. Explain why the strength of the magnetic field at point C is zero? The Attempt at a Solution The like poles repel each...

Hello all, thanks for reading. I'm in the process of designing a machine that will move a hall effect sensor in 3 dimensions through a magnetic field and record readings. Before I started the design however, I wanted to see if there would be huge problems in how I envision this machine...

Can an electromagnetic wave be deflected by electric or magnetic field.