Magnetic Definition and 1000 Threads

Also does it make a better core for an electromagnet than iron does?

I would very much appreciate a clarification on what is meant by a changing electric field in the context of statements such as 'a changing electric field creates a changing magnetic field'. My question is does the electric field actually need to reverse as a lot of examples show where two...

This has been noodling in the back of my mind ever since I read about the field strength in magnetars etc. Magnetic fields store energy. Magnetic fields in magnetars are inconceivably large (~10^11T). This inconceivably large magnetic field contains ~4x10^27J/m3 From that famous guy whose...

Hello folks, I did some research and I know a charged particle in a coil magnetic field travels along the lines of the coil. My thoughts are having a vertical cylinder and having charged ions flow down. 1. How can I figure out how much velocity the charged ions would have. 2. Would it...

How to find true north vs magnetic north? Online information says magnetic north moves around as much as 2.5 degrees. Lots of information online about true north 1 place save 5 degrees off magnetic, another place says 10 to 12 degrees, another place 10 to 25 degree, another place 15 to 30...

<Moderator's note: Moved from a technical forum and thus no template.> Hello all, Earlier today I had an electromagnetism exam, and it seems to me that this problem is unsolvable. There's just too little information given. A proton enters an uniform magnetic field. It's initial speed v is...

Homework Statement A certain commercial mass spectrometer is used to separate uranium ions of mass 3.92 multiplied by 10-25 kg and charge 3.20 multiplied by 10-19 C from related species. The ions are accelerated through a potential difference of 100 kV and then pass into a uniform magnetic...

1. The problem statement, all variables, and given/known data Assume the Earth’s magnetic field is 52.0 mT northward at 60.08 below the horizontal in Atlanta, Georgia. A tube in a neon sign stretches between two diagonally opposite corners of a shop window—which lies in a north-south vertical...

Homework Statement A rod of mass 0.720 kg and radius 6.00 cm rests on two parallel rails that are d=12.0 cm apart and L=45.0 cm long. The rod carries a current of I=48.0 A in a direction that makes it rolls along the rails without slipping. A uniform magnetic field of magnitude 0.240 T is...

<Moderator's note: Moved from a technical forum and thus no template.> So there was this question An electron that has velocity (2*10^6 i +3*10^6 j)m/s moves through the uniform magnetic field (0.03 i - 0.15 j) T (a) Find the force on the electron due to the magnetic field. (b) Repeat your...

Homework Statement charged particule reaches a uniform magnetic B field with a velocity V , and at angle theta with the magnetic field . What is the expression of the relation , expressed as a ratio, of the radius and helical step of the trajectory of the particule . a- 2pi/tan a b- 2pi...

Homework Statement a magnetic moment of U = 1 (i) + 2 (k) , surrounded by a magnetic uniform field of B= 3 (i) + 4 (j) - 1 (k) find the potential energy in mJ ? Homework Equations dot product of 2 vectors ( ui*bi)+(uj*bj)+(uk*bk) = or finding the module of both vector and doing AB...

ok so 1- the magnetic momentum is = to u in the k axis ( xyz - ijk ) and the magnetic field B = -A/z4 + Be^Cz) , also in the k axis orientation so the magnetic force F , that is applied on the magnetic momentum is given by 4 choices ; and as i can understnd it, 3 of them are...

Homework Statement So I came across with following problem: > Consider a cylindrical conductor of infinite length and circular section of radius a and that is traversed by a stationary current I. What is the magnetic energy stored in the conductor. Homework Equations 3. The Attempt at a...

Homework Statement This a question from an olevel paper and the marking scheme says B I don't understand why Homework Equations None a theory question The Attempt at a Solution Aluminum and copper has less magnetic property while iron is good magnetic material. I cannot understand why the...

A long thin current-carrying conductor have a magnetic field around it in the direction according the RHR. If a compass needle was placed beside the wire it moves to point in the direction of the magnetic field. Now the current in the wire doesn't diminish and can still light a bulb in its way...

Homework Statement A wire with a current of I (flowing into the screen) moves down on a slope. What is the direction of the magnetic force acting on it? Homework EquationsThe Attempt at a Solution I have no Idea why the answer isn't horizontal, but rather opposing its velocity direction.

Homework Statement Hello, this is like an experiment of engineering.It is called a induction stove. The system consists of a bycicle, where I am going to pedal. This will turn a disk that have 20 small magnets around its circuference. Once the disk starts to turn, it will produce a constant...

Homework Statement Consider a cylinder of thickness a=1 mm and radius R = 1 cm that is uniformly magnetized across z axis being its magnetization M= 10^5 A./m. Calculate the bound currents on the cylinder and, doing convenient approximations, the B field on the axis of the cylinder for z=0...

Hi, I studied the Maxwell laws and the Biot Savart law and I found something I cannot answer. If you have a finite wire carrying current (let say 5m long) and you want to determine the magnetic induction vector due to it at some point that has distance r from the wire, you have 2 options I...

Homework Statement Homework EquationsThe Attempt at a Solution The current in the inner loop should flow in anticlockwise direction so as to resist the increase in flux of the external magnetic field . But how do I deal with the outer loop since there is smaller loop inside it ? I think...

Homework Statement Homework EquationsThe Attempt at a Solution I have honestly no idea about this concept . Book doesn't mention anything about this . This looks similar to Faraday cage in electrostatics . But I don't understand how this works in case of magnetic fields . Is this related to...

Homework Statement Homework EquationsThe Attempt at a Solution I am having trouble interpreting the language of the problem statement . What does it mean that "half number of turns are wound " ? When the solenoid is cut , the length becomes 1/4th of the original and number of turns also...

Homework Statement There is a magnetic field B=0.02 Tesla and its direction is toward the plane (perpendicular to plane, shown by X X X X X - I'm not sure how to say this direction in English,sorry). we have a copper wire (uniform bar) perpendicular to magnetic field from south to north. we...

Homework Statement A wire carrying current I=7A is shaped as half circle of radius R=0.2m.The magnetic field B(in μT) at the center is : A)11.0(k) B)7.9(k) C)9.4(k) D)6.3(k) E)4.0(-k) Homework Equations B=(μ0 I)/(2πR) The Attempt at a Solution B = (4π*10-7 *7)/(0.2*2*π) * 0.5 (Multiply by 1/2...

Homework Statement Homework Equations B=(μ0*I)/(2πr) The Attempt at a Solution B2 = (4*4*10-7)/(2*0.1) = 8 μT B1 = (3*4*10-7)/(2*0.1) = 6μT Could I know how to determine the directions ?

I have tried looking this question up and I hope I am posting this question in the correct spot. I have read a little about photon clouds which surround electrons in a magnet but since I see myself as a very visual learner I think I am trying to think about this question as if something is...

Let's say I have a bullet flying by a magnet, the magnet will attract the bullet and change its trajectory so it will turn slightly. Does that trajectory change take energy? If it does, where does it come from? The kinetic energy of the bullet?

I would like to receive some input about this "equation" formulated by me, a=f(i), regarding a system with a permanent magnet and an air core coil acting as an electromagnet, as described in the image: I understand that the acceleration provided to the toy car will be a function of the...

Homework Statement [IMG]http://[url=https://ibb.co/b3Emfo]https://preview.ibb.co/gLaEY8/20180527_055248.jpg[ A conducting bar slides down without friction on a pair of conducting rails separated by distance d. Connected to resistor R and there magnetic field B directed upward, perpendicular to...

can we modify a single magnet in a way which creates force on non-magnetic object

I need to find out how calculate magnetic forces appearing in AC induction motor rotor when it is not magnetically centered inside the stator.

Homework Statement A small conducting rod of length l moves with a uniform velocity v in a uniform magnetic field B. Explain how the end Y becomes positively charged. Homework EquationsThe Attempt at a Solution I know the concept, a force will act on the conductor which will push the...

Homework Statement This is a multi choice question from last years aqa a level. We know a positive reading is produced on the scales indicating something is pushing down on the scales. Please see the picture. Homework Equations We know current direction, not B field. The Attempt at a...

I know that the poles of an electromagnet that is straight is at the ends but what if the metal core is an iron ring?

"Calculated the total magnetic moment of a hydrogen atom in the ground state in a weak magnetic field which arises from hyper fine splitting of the ground state. How many beams does hydrogen produce from a Stern-Gerlach analyzer with a weak magnetic field?" I've calculated the magnetic moments...

Homework Statement A magnetic field perpendicular to the plane of a wire loop is uniform in space but changes with time tin the region of the loop. If the induced emf in the loop increases linearly with time t, then the magnitude of the magnetic field must be proportional to: a)t^3 b)t^2...

Consider that we have a magnet and a magnetometer (a fluxgate magnetometer with a single coil), standing still as shown in fig 1. In fig 1, the magnetic field measured at the axis z1 of the magnetometer coil is B1. But if everything (magnet, magnetometer and the axes) was rotating together...

Homework Statement So I have got the question below. I am asked to find the phase difference between the electric field and magnetic field of electromagnetic waves traveling in a plasma, using the electrical conductivity expression. Now I have found the frequency of the waves and I know that...

Both the gravitational and electric fields associated with matter are centered on the matter itself. However, for a bar magnet, the magnetic field seems to be emanate from discrete loops, only part of which pass through the matter of the magnet. What causes a magnetic field to have this...

Homework Statement Homework EquationsThe Attempt at a Solution To calculate magnetic field at 1 and 3 current flowing through sections A and C can be assumed as if current is flowing in a long straight wire along the dotted line . Now since the current and distances are same for 1 and 3 , B1...

Homework Statement [/B] There is lead XY shaped as straight wire. Next to it, circular lead with radius 0.10 m. They are in the same plane. XY to center of circle, O is 0.20 m. Curent flowing through XY is 15.7 AHomework EquationsThe Attempt at a Solution 1) find magnetic field (B) at O[/B]...

If I understand it so far - a ferromagnetic object is attracted to a magnetic field ie towards the direction of most concentrated flux. So if there is no gradient there is no net force on the object. If the flux is so strong that the object magnetically saturates, then increases in flux will...

Homework Statement For a medium of conductivity ##\sigma##: $$ \nabla^2 \vec{B} = \sigma \mu \mu_0 \frac{\partial \vec{B}}{\partial t} + \mu \mu_0 \epsilon \epsilon_0 \frac{\partial^2 \vec{B}}{\partial^2 t} $$ A long solenoid with ##r=b## has n turns per unit length of superconducting wire anc...

Homework Statement Homework Equations m=N*I*A T=m X B m = n(unit vector) *m The Attempt at a Solution To calculate m, I know it is just plugging in the information. Thus, m=0.8. Now, the question is computing the unit vector, which has me confused. Using the right hand rule, and going along...

Homework Statement A cylinder with radius ##R## and height ##h## which has a distributed charge on its surface with density ##\sigma## spins over its axis with angular velocity ##\omega##. If the cylinder has a mass density ##\rho##, find the relationship between magnetic momentum and angular...

Homework Statement This is from Griffith's Introduction to Electrodynamics, where the book is deriving the magnetic dipole moment from multipole expansion of the vector potential The vector potential of a current loop can be written as $$\mathbf{A(r)}=\frac{\mu_0 I}{4\pi} \left[ \frac{1}{r}...

Hi, I've seen many videos of neodymium magnets sliding slowly down an inclined copper plate, or slowly down a copper tube - due to eddy current braking,but never the other way around. My question is; will a copper disc sliding down an inclined magnetic plate, or down a magnetic tube act in the...

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...

Homework Statement Could someone please see if my working are correct for this question, I have never actually done a question of this nature before, and after reading up about the derivation on the perturbation I thought I give ago and apply, my final answer dose not seem correct, as I believe...