Magnetic Definition and 1000 Threads

  1. S

    Magnetic Field of a Rectangular Loop at Point P

    Homework Statement Find the magnetic field at the point distance R outside a rectangular loop of sides 2R, 4R carrying current I as shown in the attached diagram Homework Equations Biot-Savart Law The Attempt at a Solution Could I just break this up into 4 separate lines and then calculate...
  2. L

    Magnetic Flux through conductor coil

    Homework Statement Consider a conductor loop which rotates about the y-axis with angular velocity w. The positive y-axis is directed into the paper, the x-axis to the right and the z-axis upwards. There is an inhomogeneous magnetic field along the positive x-axis. Calculate the magnetic flux...
  3. sergiokapone

    Electrictric field due to changing uniform magnetic field

    How does look like electric field lines due to change of the uniform magnetic field? Suppose we have a magnetic field between two infunite plates with surface current $i$ which is lineary change with time. Then B-filel is (x - perpendicular to plates, z and y along plates) \begin{equation} B_z =...
  4. abilolado

    I Force on Steel Bar Inside Solenoid

    Hello all. Me and some friends are building a coil cannon, and we've been doing some calculations [I know its unecessary but... well, we're physicists! (well, physics students...)]. But we got stuck. How to calculate the force acting on a steel bar (or some other ferromagnetic material, maybe...
  5. G

    Finding True North for Solar Panel Placement: A Simple Method

    I learned this in college 48 years go, problem is I have forgotten more than I ever knew. I know the answer is not very hard like 20 degrees but the internet is pissing me off. I looked this up and I get FAKE stuff like advertisements. Novels with many pages to read that never tell the...
  6. C

    Calculating Magnetic Force for Homework Assignments

    Homework Statement Homework EquationsThe Attempt at a Solution Is it A?
  7. C

    Direction of Magnetic Field with Current and Motion in Same Direction?

    Homework Statement Homework EquationsThe Attempt at a Solution using the left hand rule, second finger points the direction of current, thumb points direction of motion and first finger the direction of magnetic field. But If direction of current and motion is the same, what do I do? Thanks~
  8. J6204

    What is the correct magnetic force on the rectangular loop in this figure?

    Homework Statement A rectangular loop of wire, L = 28.8 cm and W = 15.2 cm, carries a I1 = 2.02 A current and lies in a plane (d = 11.0 cm), which also contains a very long straight wire carrying a I2 = 12.7 A current as shown in the figure below. Homework Equations F=uo*i1*i2*l/perpindicular...
  9. Hardik Batra

    Magnetic force relation with v and r?

    (1) Magnetic force acting on charge moving in magnetic field is given by, F = qvBsinθ...F ∝ v This means that if moving charge particle has more velocity then more magnetic force will act on it. Due to more magnetic force the direction of velocity changes rapidly and it will move on the...
  10. C

    Direction of the magnetic field

    Homework Statement Homework EquationsThe Attempt at a Solution I know if the currents are going the same direction they attract. So the top 2 attract each other and the bottom two attraction each other? And then the top repel the bottom... I'm stuck, please help~
  11. C

    Comparing Magnetic Field Strengths with Vectors

    Homework Statement Homework EquationsThe Attempt at a Solution Shouldn't they be the same? Does one being above the current and the other being below make any difference? I know when there is a higher density of magnetic field lines, the magnetic field strength is greater, but in this case...
  12. chopnhack

    Force on an electron in a magnetic field

    Homework Statement What is the force on an electron with a velocity v = (2i – 3j) Mms-1 in a magnetic field B = (0.8i + 0.6j – 0.4k) T Homework Equations F=qvBsinθ The Attempt at a Solution using cross product I got: (1.92i + 1.28j + 5.77k)10^-13 N which is the listed correct answer. My...
  13. M

    Magnetic levitation with permanent magnets

    so i am literally one step away from producing a floating skateboard powered by permanent magnets, so here's what i wanted to check, to make sure I haven't missed anything obvious vertical lift achieved by using vertical repelling fields rotational motion is controlled by counterbalancing the...
  14. T

    Calculating the mutual coupling coefficient of E cores

    Hi, I can't find my inductance calculations book. Say that you were considering magnetic flux linkage more from a geometric perspective: -Does the mutual coupling coefficient for a series of coils all on the same steel core add up to a maximum total of ~1? Because I tried simulating a three...
  15. L

    Magnetic Field of a Line between two wires

    Homework Statement Two wires with the same intensity but with opposite directions. The magnetic field of the middle line between the two wires is: a) (X) b) (o) c) Parallel between the two wires d) Null e) Non of the above. Homework Equations N/A The Attempt at a Solution Knowing that they...
  16. S

    What magnetic position sensor to choose?

    I want to record the displacement of a small magnetic ball moving sideways across the face of the sensor. I've had a close look at AMS's catalog of magnetic position sensors and I'm not sure how to choose one. If I'm working with a movement range of <5mm and want a resolution of 5-10μm, and...
  17. O

    What moves in a magnetic field?

    So if you have a permanent magnet what is moving along the magnetic field lines? Electrons? Photons?
  18. J

    Lenz's Law and Induced Magnetic Fields

    In a transformer, the primary coil has a current running through it which creates a magnetic field. Then this field induces a current in the secondary coil. That induced current creates a magnetic field exactly opposite the inducing magnetic field. This might be an obvious question, but that...
  19. arpon

    I Four-vector Dipole Moment: Electric & Magnetic

    What is the four-vector related to electric and magnetic dipole moment?
  20. S

    Calculating Magnetic Energy in Permanent Magnets

    Hi folk Is there a method to calculate the magnetic energy stored in a permanent magnet ? Thanks for help
  21. T

    Electric and Magnetic Fields: A Proton's Motion

    Homework Statement A proton moves with constant velocity in a certain region of gravity-free space.Which one of the following conclusions is valid? A)There must be no electric field or magnetic fields in the region. B)There could be an electric field without any magnetic field. C)There could be...
  22. Buckethead

    B Faraday's disk and "absolute" magnetic fields

    I've posted this here because I think it might be related to the absoluteness of acceleration and rotation. I've been educating myself on the Faraday Disk and was very surprised by one aspect of it. If we have a solid metal disk mounted on a shaft with two electrical brushes contacting the...
  23. T

    Magnetic pressure on a conductor

    Homework Statement Homework EquationsThe Attempt at a Solution i have done the first two parts but the third part confuses me i am assuming the current is flowing in the z direction then current is parallel to the magnetic field then why would there be a force acting on it ?[/B]
  24. G

    Can someone help me find an equation for magnetic force?

    The equation needs to describe the force between two magnets and should relate to distance, angular frequency, angular acceleration, and torque. I need to find this equation for a research project, but I just can't figure it out and I can't find it online. (I'm new to this website so if this is...
  25. P

    Rotor magnetic field and stator magnetic field

    This is one of the big confusions i have. When rotor magnetic field is 90 degrees with respect to stator magnetic field we get maximum torque. In field oriented control the a, b, c axis is converted to d and q axis. So making d axis to 0 and q axis to torque and running through pi loop does...
  26. anonyaway

    Rotating disc in a rotating magnetic field

    Homework Statement :A metallic disc of radius R is placed perpendicular to a magnetic field B.Both the magnetic field and the disc rotate with an angular velocity w about the axis of the disc.Find the induced EMF between the center and the circumference[/B]Homework Equations Motional Emf=Bvl...
  27. F

    Group of particles in a magnetic field

    Homework Statement A group of particles is traveling in a magnetic field of unknown magnitude and direction. You observe that a proton moving at 1.50 km/s in the +x-direction experiences a force of 2.25 x ##10^{-16}##N in the +y-direction, and an electron moving at 4.75 km/s in the -z-direction...
  28. F

    Direction of magnetic field and moving particle

    Homework Statement A particle of mass 0.195 g carries a charge of -2.50 x 10-8C. The particle is given an initial horizontal velocity that is due north and has magnitude 4.00 x 104 m/s. What are the magnitude and direction of the minimum magnetic field that will keep the particle moving in the...
  29. A

    What is a magnetic field "made" of?

    I have looked this up on several occassions and never satisfied. It seems that either the answer keeps repeating magnetic or electromagnetic field over and over. Or the answer discuss the properties of electromagnetism. Is the field a wave/particle like a photon ? Is it emitted like a photon...
  30. Astronaut

    Magnetic Forces on objects in nonuniform fields

    I have this question which I need to solve . But I am unable to. Suppose I have a current ring of radius R and current I (constant). at a distance x from the centre of the ring, I have a iron disk (radius r and thickness t) present in the plane of the ring. This disk will be attracted to the...
  31. A

    What if Earth was exposed to a huge magnetic field?

    What would happen if the entire Earth was somehow exposed to a massive magnetic field, such as those found near magnetars, like 10^10 teslas, for about 1 second? Would everyone instantly die? What would be the impact of a moving magnetic field vs a stationary magnetic field be? How much time...
  32. sean1832725142

    Magnetic Energy of solenoid( u=m·B or u=B^2/4pi )

    Hi, I have a problem with the fomular u=m·B and u=B^2/4pi Since I want to calculate how many magnetic energy on a solenoid, I couldn't decide which fomular should I use.
  33. Decimal

    Magnetic field from a wire at a point

    Homework Statement Picture of the problem: I first need to calculate the magnetic field in point P caused by the piece of wire at z = R (so the top wire parallel to the y-axis). Homework Equations [/B] Biot-Savart law for magnetic fields: ##\vec {dB} = \frac {μ0*I} {4*π} * \frac {\vec {dl}...
  34. R

    Is it possible to create a hollow magnetic sphere?

    Is it possible to create a hollow magnetic sphere?
  35. G

    A Does Magnetic Braking Theory hold up?

    Magnetic braking is a theory explains the loss of stellar angular momentum and is used extensively to describe the given rotation stars. However, on a smaller and more directly observable level, when we consider Jupiter's rapid rotation rate of less than ten hours and its accompanying powerful...
  36. A

    Textbooks for Electromagnetics, Dielectrics, Magnetic field and Polarisation

    I am a Graduate student in Electrical Engineering. I have to work on Electromagnetic, Dielectric, Magnetic field and Polarization for my project. But my problem is I do not have a good background in this course. Now, I really need it in graduate level. My question is, can you guys introduce me a...
  37. esha

    Magnetic properties of electrons

    my textbook says that electrons have a basic characteristic of magnetism just like charge and mass. this magnetic property in some materials adds up to result in a permanent magnet and in some others nullifies each other. how does it really occur? moreover if electrons hav magnetic properties...
  38. U

    Need explanation about magnetic forces

    Hi, I saw this video and I can't explain why the magnet is propelled to the end of the coil with such a huge force. Can someone explain it in clear terms. I also tried to use Flemings left hand (or right hand) rule but it did not give me a satisfactory answer. Thanks, SM
  39. I

    Question about making a coaxial magnetic field in a pipe

    Hi, for a particular project, I would like to create a 1~2 Tesla magnetic field in a stainless steel pipe along the z axis. I was wondering if my concept would work, or if anyone had better ideas. Here's my concept. Fig1. So I got a few pipes about 1 inch in diameter. I would like to have a...
  40. P

    3 phase motor net magnetic field

    I am trying to understand the basics of bldc motor. My question is if i am driving the 3 phase motor with sinusoidal waveform. The magnetic field is produced for each phase or it will add together to generate net magnetic field? How to get the net magnetic field.
  41. E

    About magnetic field attraction

    We know a magnet has field with direction from North to South. Why when a piece of iron come close to the magnet can either be attracted and from both sites and not for example from one pole?
  42. H

    Electrons move, causing magnetic force, find v?

    Homework Statement Homework Equations f = q.v.B.sin tetha I = q/t = v/R The Attempt at a Solution (1) q =a.b.n.v.t is it right? (2) I = q/t = abnvt/t = abnv is it right? (3)F = q.v.B is it right? (4) ? (5) ? is it right?
  43. V

    Magnetic compass and Earth's magnetic field

    Hello , I am having a slight confusion while reading the chapter on Earth's magnetism . If we place a magnetic compass on the floor I.e on Earth's surface , the North (red) of the compass needle points towards magnetic north of Earth . But would it be correct to say that "the compass needle...
  44. Arshavsky

    Net force on a Halbach Array in a uniform magnetic field

    I have been unable to determine whether a Halbach Array of permanent magnets would experience a net force in a uniform magnetic field.
  45. D

    Could a distribution of magnetic Dipoles create an Energy minimum

    The think is that I would like to create a magnetic trap "minimum of magnetic potential energy in all 3 directions of space" using a distribution of magnetic dipoles as a field generator. In other words, I would like to know if setting in some way some magnetic dipoles is possible to create a...
  46. A

    How can the neutral outer core generate a magnetic field?

    Even if the outer core is convecting and conductive it is still charge neutral, so how can a Magnetic field be generated? Maxwells Equation say there needs to be net charge moving for a Magnetic field to be generated.
  47. M

    Magnetic field of a finite wire increasing with distance?

    I am computing magnetic field around a thick conductor to do railgun force modeling. I am currently re-examining my magnetic field computation, and I have found some confusing results stemming from a fairly simple use of the Biot-Savart Law. The main issue is that the more nuanced application of...
  48. Asmaa Mohammad

    The average EMF in a coil rotating in a magnetic field

    Homework Statement [/B] Homework EquationsThe Attempt at a Solution Solution for Q1: Solution for Q2: Solution for Q3: Are they correct?
  49. Asmaa Mohammad

    The rate of change in the magnetic field linkage in a coil

    Hi, I would appreciate it if someone explains the difference between these two phases regarding a coil rotates in a uniform magnetic field. 1. The rate with which the coil intercepts the lines of magnetic field in the dynamo is maximum when the plane of the coil is parallel to the lines of the...
  50. Asmaa Mohammad

    The magnetic flux and the induce emf in the dynamo.

    Homework Statement Multiple-choice question: Homework EquationsThe Attempt at a Solution I know that the induced emf is maximum when the coil is parallel to the direction of the magnetic flux, so I should choose either B or C, and I have read the the rate by which the coil cut the magnetic...
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