Magnetic field Definition and 1000 Threads

Don't know if this is the right place to post this, but it seemed like the best place to start. I'm wondering how much stronger would the Earth's magnetic field need to be in order to make quantum levitation using Earth's magnetic field alone a possibility. Bonus: Effects the change in strength...

Homework Statement I am trying to solve a problem that I have invented. It consists of a metal stick of mass m, which falls by the action of gravity (g=constant) within a perpendicular constant magnetic field B. The direction of magnetic fiel is showed in the image. The stick makes electrical...

Hi all, Not a question about completing homework here, but I'm a teacher looking to create a realistic engineering question for an assignment. I have an engineering scenario I've set for the assignment which is a junior engineer working for a marine engineering company so all of the questions...

Homework Statement A proton is projected perpendicularly into a magnetic field that has a magnitude of 0.30 T. The field is then adjusted so that an electron will follow a circular path of the same radius when it is projected perpendicularly into the field with the same velocity that the proton...

Homework Statement One component of a magnetic field has a magnitude of 0.0431 T and points along the +x axis, while the other component has a magnitude of 0.0686 T and points along the -y axis. A particle carrying a charge of +1.70 × 10-5 C is moving along the +z axis at a speed of 4.24 × 103...

What if an electromagnet's core is on the outside? How would it's magnetic field look? (The wire being wrapped in coils on the inside of a tube or pipe looking metal)

If your fingers of one hand curl around the axis of rotation of the accretion disc of a massive black hole and your fingers point in the direction of the flow is the direction of the central twisted poloidal magnetic field given by a right hand rule, a left hand rule, no rule? Is there a simple...

Could anyone point me to the proper formula to calculate the magnetic field strength in the gap/hole(ID) of a diametrically magnatized ring magnet. https://www.skycraftsurplus.com/rp9291magnetdonut17odx08id-1.aspx

Hello! I am confused about the first EM problem on http://web.mit.edu/physics/current/graduate/exams/gen2_F00.pdf (page 4, with the cylinder in a magnetic field). The solution can be found http://web.mit.edu/physics/current/graduate/exams/gen2sol_F00.pdf. In part a the solution is...

What happens to the velocity? Say we have a piece of space debris in free fall. It has a particular velocity at a given time. Then say at some later time it's bombarded with ionic gas or something that causes it to become charged. Does the velocity change? My guess would be yes, because the...

Can somebody please post the derivation of the ABC magnetic field components whose magnetic field components in the three cartesian directions(B1, B2, B3) are given by the following: B1=A*sin(z)+C*cos(y) B2=B*sin(x)+A*cos(z) B3=C*sin(y)+B*cos(x)

How does plasma particles (ions, electrons, neutral particles as a whole) interact with an applied steady-state magnetic field? If you have plasma at atmospheric pressure ejected from a plasma torch in the z-axis direction (upwards/north), how will two permanent magnets, axially aligned N-S to...

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...

<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...

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...

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...

I know that the right hand rule applies for induced currents, and the left hand rule is for motors, but why? It doesn't seem to connect with any other physics laws and is very counter-intuitive that the current will flow in one direction rather than the opposite direction if both are...

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...

For a Year 12 Assignment I have to do a seminar on how magnetic fields are involved with a certain topic. I chose nuclear fusion energy production and specifically the tokamak. I understand that a toroidal magnetic field is created when a current is sent through a solenoid wrapped in a torus...

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?

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

I've been given a question to find the magnetic flux density of the Earth if an electron is orbiting near to the surface. The answer to the question makes the magnetic force equal to the centripetal force and solves for B from there. However, I am confused to why the gravitational force has no...

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...

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 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 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...

Homework Statement Homework EquationsThe Attempt at a Solution I am considering the two rods separately .Considering QP alone EMF induced will be (1/2)Bωl2 with Q at higher potential . Considering QR alone EMF induced will be (1/2)Bωl2 with Q at higher potential . This gives zero potential...

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...

Homework Statement In the central region of a solenoid that is connected to a radio frequency power source, the magnetic field oscillates at 2.5·10^6 cycles per second with an amplitude of 4 gauss. What is the amplitude of the oscillating electric field at a point 3 cm from the axis? (This...

Homework Statement Homework EquationsThe Attempt at a Solution I have already solved for the magnetic fields everywhere AND THE magnetic field at R>F = (U/2*PI*R)*(I2-I1) My only problem is i know i use the right hand rule to determine the direction of the magnetic field B as clockwise or...

Homework Statement Consider a toroidal electromagnet filled with a magnetic material of large permeability µ. The torus contains a small vacuum gap of length h. Over most of its length the torus has a circular cross section of radius R, but towards the gap the torus is tapered on both of its...

When can we use the right hand rule to find the direction of a magnetic field from current? I know that it works for an infinite wire. Does it work for a finite wire? Where does it work and not work?

Homework Statement Homework Equations Emf=B l V V is (velocity) F=QVB The Attempt at a Solution Emf=BLV Work=QBLV Force=BLV how come V=Q/m. its not possible or is it?