What is Uniform magnetic field: Definition and 101 Discussions

In physics, circular motion is a movement of an object along the circumference of a circle or rotation along a circular path. It can be uniform, with constant angular rate of rotation and constant speed, or non-uniform with a changing rate of rotation. The rotation around a fixed axis of a three-dimensional body involves circular motion of its parts. The equations of motion describe the movement of the center of mass of a body. In circular motion, the distance between the body and a fixed point on the surface remains the same.
Examples of circular motion include: an artificial satellite orbiting the Earth at a constant height, a ceiling fan's blades rotating around a hub, a stone which is tied to a rope and is being swung in circles, a car turning through a curve in a race track, an electron moving perpendicular to a uniform magnetic field, and a gear turning inside a mechanism.
Since the object's velocity vector is constantly changing direction, the moving object is undergoing acceleration by a centripetal force in the direction of the center of rotation. Without this acceleration, the object would move in a straight line, according to Newton's laws of motion.

View More On Wikipedia.org
Recent contents Top users
  1. B

    Motion of a charged particle in a uniform magnetic field

    See attachment. I don't why a charged particle in a uniform magnetic field will move in a circle. Why can't it just continue straight in the direction its going until another force acts on it?
  2. M

    Current carrying wire in uniform magnetic field; where is net magnetic field 0?

    Homework Statement A long wire carrying 100 A is perpendicular to the magnetic field lines of a uniform magnetic field of magnitude 5.0 mT. At what distance from the wire is the net magnetic field equal to zero? Homework Equations B = iμo/2∏R The Attempt at a Solution I...
  3. T

    [Statistical Physics] Spin-1 atoms in uniform magnetic field

    Homework Statement A crystal contains N atoms which posses spin 1 and magnetic moment \mu. Placed in a uniform magnetic field B the atoms can orient themselves in three directions: parallel, perpendicular, and antiparallel to the field. If the crystal is in thermal equilibrium at temperature...
  4. E

    Why does the magnetic moment of a nucleon line up with a uniform magnetic field?

    I thought the external magnetic field had to vary within an object in order for that object's magnetic moment to line up with the field.
  5. A

    Sliding Bar in a Uniform Magnetic Field

    Homework Statement A metal bar with length L, mass m, and resistance R is placed on frictionless metal rails that are inclined at an angle \phi above the horizontal. The rails have negligible resistance. A uniform magnetic field of magnitude is directed downward in the figure B. The bar is...
  6. C

    Charged particle motion in a uniform magnetic field

    Consider that we have a macroscopic, electrically charged, point object tracing out a circular path in a uniform magnetic field in the usual way due to the Lorentz force. Now we very slowly raise the overall strength of the magnetic field (slow enough that on one orbit, the object sees the same...
  7. L

    Torque experienced by a current loop in uniform magnetic field

    Homework Statement Revered members, please see my attachment (1) In this diagram, PQRS is a rectangular current loop and I is the current and its direction is shown in red arrow . B is the magnetic field and it acts from left to right and n is the normal drawn to the plane of the loop...
  8. G

    Induced emf when accelerates in uniform magnetic field

    Hi everyone, This question is bothering me for days and would hope to receive some help in this forum. This question is with regards to Faraday's law on EMI. Will an emf be induced when a copper rod is accelerated between a uniform magnetic field? My answer would be no if the rod has...
  9. M

    Uniform magnetic field problem

    Homework Statement A proton, with mass 1.67*10^-27 kg and charge +1.6*10^-19C, is sent with velocity 5.0*10^4 m/s in the x-direction into a region where there is uniform electric field of magnitude 390 V/m in the y direction. What is the magnitude and direction of the uniform magnetic field in...
  10. M

    Magnitude and direction of uniform magnetic field

    Homework Statement A proton, with mass 1.67*10^-27 kg and charge +1.6*10^-19C, is sent with velocity 5.0*10^4 m/s in the x-direction into a region where there is uniform electric field of magnitude 390 V/m in the y direction. What is the magnitude and direction of the uniform magnetic field in...
  11. jegues

    Hanging Wire Uniform Magnetic Field

    [SOLVED]Hanging Wire Uniform Magnetic Field Homework Statement See figure attached. Homework Equations The Attempt at a Solution \vec{F_{b}} = i\vec{L} \times \vec{B} Using my right hand rule, I can see that the force is pushing the wire to the right. This correlates with...
  12. Y

    Find induced E field inside a disk in an uniform magnetic field.

    Homework Statement Uniform time varying magnetic field \vec B_{(t)} pointing at z direction, filling up a circular region on xy-plane. Find the induced E field. I tried two different ways and get two different answers. Please tell me what did I do wrong. Homework Equations Emf...
  13. L

    Paramagnetic rod in a uniform magnetic field

    Hello Physics Forums. I've read the forum on and off for a while and have always found that the folks here have given such thorough answers that I've had nothing more to contribute! :) But I finally have the need to ask a question. I work in a physics lab and we are trying to determine the...
  14. B

    Finding Momentum with Uniform Magnetic Field: q, B, a, d

    Homework Statement A particle of charge q enters a region of uniform magnetic field B (pointing into the page). The field deflects a particle a distance d above the original line of flight. Is the charge positive or negative? In terms of a, d, B, and q, find the momentum of the particle. x...
  15. A

    Uniform magnetic field problem

    A proton (mass= 1.7×10-27 kg, charge= 1.6×10-19 C) traveling with speed 106 m/s enters a region of space containing a uniform magnetic field of 1.2 T. What is the time t required for the proton to re-emerge into the field-free region? I plugged the numbers into r=mv/qB and then t=pi r/ v...
  16. M

    Motion of charged particle in uniform magnetic field

    Homework Statement Accelerating voltage of 2500V is applied to an electron gun producing a beam of e- originally traveling horizontally north in a vacuum toward a viewing screen 25cm away. a. What are the magnitude and direction of the deflection caused by Earth's gravitational field? b. What...
  17. A

    Linear acceleration in a uniform magnetic field due to torque

    Here the extra credit question I'm stuck on: A square loop (perimeter of 4L and hinged along one side) is made of a wire that has a mass per unit length of 0.1000 kg/m and carries a current of 5.000 A. A uniform magnetic field of 10.00 mT directed perpendicular to the hinged side exists in...
  18. D

    A neutral metal rod in a uniform magnetic field

    Homework Statement A neutral metal rod of length 0.35 m slides horizontally at a constant speed of 9 m/s on frictionless insulating rails through a region of uniform magnetic field of magnitude 0.6 tesla, directed into the page as shown in the diagram. Before answering the following...
  19. L

    Ranking velocities of particles in uniform magnetic field

    1. Five equal-mass particles (A–E) enter a region of uniform magnetic field directed into the page. They follow the trajectories illustrated in the figure. Rank from largest to smallest velocity 2. qvBsin(theta) = ma qvB = ma = m(v^2/r) v = qBr/m 3. Based on their...
  20. F

    Uniform magnetic field in a spherical region

    Homework Statement Is it possible to design a current winding that will produce a uniform magnetic field in a spherical region of space? Homework Equations Well, the literature tells that the equation for the B-field for a uniformly magnetized sphere = (2/3)u_0 * M and also the...
  21. J

    Does a uniform magnetic field without fringing exist?

    Homework Statement Show that a iform magnetic field that has no fringing field is impossible because it violates ampere's law. Do this calculation by applying Ampere's Law to a rectangle that contains the edge of the field with two sides running parallel to the field. Homework Equations...
  22. P

    Wire Loop falling through uniform magnetic field

    Homework Statement A square loop is cut out of a thick sheet of aluminum. It is then placed so that the top portion is in a uniform magnetic field B, and allowed to fall under gravity. (B is perpendicular to the loop) If the magnetic field is 1 T, find the terminal velocity of the loop...
  23. R

    Particle Traveling in a Uniform Magnetic Field (SR?)

    Let a particle mass m charge q be placed in a uniform magnetic field \vec B = B\hat k with an initial velocity v_0\hat i Clearly, it will enter a circular path of radius so and so with angular frequency so and so. But, it will not move in a straight line, not at all. Its momentum will...
  24. M

    Metal frame moved through uniform magnetic field

    A square rigid metal frame PQRS, of side 12 cm, forms a closed circuit with an ammeter. It is moved through an enclosed region of uniform magnetic field of flux density 2.0 × 10–2 T, from left to right. The field is confined to this area and directed into the page. PQRS --> magnetic field -->...
  25. T

    Calculating Velocity for Horizontal Motion in a Uniform Magnetic Field

    Homework Statement A stone with a negative net charge of 0.010C is given a constant horizontal motion in a uniform magnetic field in the direction pointing into the page. The field's strength is 1.70T. How fast does the stone have to move in order for it to remain moving horizontally, without...
  26. H

    Uniform Magnetic field in a circular coil

    A 138 turn circular coil has a diameter of 2.00 cm and resistance of 53.0 Ω. The plane of the coil is perpendicular to a uniform magnetic field of magnitude 1.00 T. The direction of the field is suddenly reversed. a.) Find the total charge that passes through the coil. b.) If the reversal...
  27. L

    Electron equations of motion through an uniform magnetic field

    Homework Statement An electron enters a zone of uniform magnetic field \vec B = 0,4T{\rm{ }}\hat j with velocity {\vec V_0} = {10^5}m/s{\rm{ }}\hat i. Find the differential equations that govern its motion through the field, and solve them to find the equations of motion. What happens to its...
  28. M

    Cathode Ray Tube in a uniform magnetic field

    Homework Statement A CRT is placed in a uniform magnetic field B, with the axis of the tube parallel to the lines of force. If electrons emerging from the gun with a velocity v make an angle θ as they pass through the origin O so that their trajectory is a helix, show that a) they will touch...
  29. M

    Lagrangian for a particle in a uniform magnetic field

    Homework Statement We know that for a uniform static magnetic field, we may take V = 0, A = 1/2 B x r (vector potential) Now, I have to write the Lagrangian L in cylindrical coordinates, but I'm not sure I'm doing it right and this goes on for hours now, so maybe someone can help me out...
  30. I

    Faraday's law and uniform magnetic field

    Hello Say there's a uniform magnetic field changing in time (B=Asin(t) or something), and a ring (pic 1). so obviously by faraday's law there would be current running through the ring caused by the induced emf. Now, say we connect 2 wires from the center of the ring up to the top and to the...
  31. B

    Electron moving through a uniform magnetic field

    The Problem: An electron moves with speed 9.00 105 m/s in a uniform magnetic field of 2.0 T, pointing south. At one instant, the electron experiences an upward magnetic force of 2.00 10-14 N. In what possible directions might the electron be moving at that instant? Give your answers as angles...
  32. G

    Calculate Initial Magnitude B of Uniform Magnetic Field

    A conducting loop has an area of A=0.065 m^2 and is positioned such that a uniform magnetic field points at θ = 60 degrees relative to the plane of the loop. When the magnitude of the magnetic field decreases to B(f) = 0.30 T in ∆t = 0.087s , the average induced emf in the loop is average ε=...
  33. 2

    What Magnetic Field Strength Keeps an Electron on a Straight Path?

    Homework Statement In the figure, an electron accelerated from rest through potential difference 1.7 kV enters the gap between two parallel plates having separation 20.0 mm and potential difference 110 V. The lower plate is at the lower potential. Neglect fringing and assume that the...
  34. I

    Electron Moving in a Uniform Magnetic Field

    Homework Statement An electron that has a velocity with x component 2.3 x 106 m/s and y component 2.9 x 106 m/s moves through a uniform magnetic field with x component 0.040 T and y component -0.12 T. (a) Find the magnitude of the magnetic force on the electron. (b) Repeat your calculation for...
  35. N

    Direction of a particle in a uniform magnetic field.

    Homework Statement a beam of particles with velocity v^vector enters a region that has a uniform magnetic field B^vector in the +x direction. show that when the x component of the displacement of one of the particles is 2 * Pi * (m / qB) * vcos(theta), where theta is the angle between...
  36. G

    Electron in a uniform magnetic field

    5. Consider an electron moving in the +x direction with speed vx, in a uniform magnetic field B = B ˆz. (a) What type of trajectory does the electron take? What happens qualitatively to its velocity in the x direction as its velocity in the y direction increases? How does its kinetic energy...
  37. E

    Work on a proton in uniform magnetic field

    Homework Statement A magnetic field of 0.1 T forces a proton beam of 1.5 mA to move in a circle of radius 0.1 m. The plane of the circle is perpendicular to the magnetic field. Of the following, which is the best estimate of the work W done by the magnetic field on the protons during one...
  38. E

    Faraday's law and a uniform magnetic field

    [SOLVED] faraday's law Homework Statement A uniform magnetic field \mathbf{B}(t) in the z-direction, fills a circular region in the x-y plane. If B is changing with time, what is the direction of \mathbf{E}/ Homework Equations The Attempt at a Solution My book says it is...
  39. Z

    Moving electron in a uniform magnetic field

    Recently, in a test, I had a question involving a magnetic field and an electron. I've attached the diagram. The "X" denote the magnetic field, moving inwards. So, there's a uniform magnetic field, moving into the plane of the picture, and there's an electron passing over that plane with its...
  40. F

    Electron's path in uniform magnetic field? Help, please

    Homework Statement There are three horizontal areas side by side - a completely uniform area. Areas 1 and 3, the magnetic fields are going into the page and area 2's field is going out of the page. An electron enters area 2 (the middle region). What is its path? Homework Equations F =...
  41. A

    Ferromagnetic dipole in a uniform magnetic field

    a- I place a ferromagnetic dipole in a uniform magnetic field so that the axis of the dipole moment vector does not lie parallel to the magnetic field lines. Is there a net force on the dipole? Is there a net force? b- I place a ferromagnetic dipole in a uniform magnetic field so that the axis...
  42. R

    What is meant by uniform magnetic field?

    Why is the force of friction independent of the area of the 2 surfaces in contact? Name a subtance used for coating to reduce friction. Is it paint? What is meant by uniform magnetic field?
  43. Amith2006

    Trajectory of charged particles in a uniform magnetic field

    1) An electron and a proton are injected into a uniform magnetic field at right angles to the direction of the field with the same Kinetic Energy. Then: a)the electron trajectory will be less curved than the proton trajectory b)the proton trajectory will be less curved than the electron...
  44. Q

    Torque on a rotating charge due to a uniform magnetic field

    Hello, I need help with an integration. I found the torque on a ball of charge with varying charge density(dependant on the radial component) in a uniform magnetic field. I got Integral[ (wxr)(r.B)(density)(r^2) sin(phi) d(theta) d(phi) dr, {r, 0,R}] where wxr is the cross product of the...
  45. P

    Magnitude and direction a uniform magnetic field

    magnetism Hi I'm stuck on this problem I its got to be something simple.Here goes... A proton moves perpendicularly to a uniform magnetic field B at 1.0x10^7 m/s and exhibits an acceleration of 2.0x10^13m/s^2 in the + x-direction when its velocity is in the + z-direction. Determine the...
  46. P

    Calculating Induced EMF for Moving Loop in Uniform Magnetic Field

    If we have a loop with radius 12 cm that lies in a uniform magnetic field of 1.5T. The magnetic field is in the positive z direction and the loop lies in the horizontal xy-plane. Now if the loop is removed from the field in a time interval of 2.0x10^-3 s what will the average induced emf be...
  47. D

    Creating a Uniform Magnetic Field Using Halbach Arrays

    Hi, I have recently stumbled across Halbach arrays while searching for ideas on creating a uniform magnetic field. The suggested configuration for the halbach array can be seen here: http://www.matchrockets.com/ether/halbach.html (First diagram at the top of the page, Magnetic flux of a...
  48. DaTario

    Apparent impossibility of uniform magnetic field

    Hi All, I would like to comment an idea and would appreciate having critics on that, as it appears to be a fallacy. According to the law for the magnetic force, if a charge is at rest relatively to some magnetic field then no net force act on it. However, if a charge is moving (no matter...
  49. R

    How can I create a 1Telsa uniform magnetic field?

    I am working on an experiment with a relatively high powered uniform magnetic field... and need to get at least 1 Tesla for it to work. I am familiar with the theories around how these fields can be created, but am curious if in practical application how one would do it. Is there a place I...
  50. G

    Analysis of Rectangular Loop in Uniform Magnetic Field

    What happens when a rectangular loop is dropped into a field of uniform, magnetic field B extending to infinity? The loop has a mass m and its resistance is R. It has length L, breadth b, L tending to infinity. Gravity is present in downward direction. The loop is dropped such that emf is...
Back
Top