What is Magnetic flux: Definition and 366 Discussions

In physics, specifically electromagnetism, the magnetic flux through a surface is the surface integral of the normal component of the magnetic field B over that surface. It is usually denoted Φ or ΦB. The SI unit of magnetic flux is the weber (Wb; in derived units, volt–seconds), and the CGS unit is the maxwell. Magnetic flux is usually measured with a fluxmeter, which contains measuring coils and electronics, that evaluates the change of voltage in the measuring coils to calculate the measurement of magnetic flux.

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

    What is the magnetic flux through a desk at a certain location on Earth?

    Homework Statement At a certain location, the Earth's magnetic field has a magnitude of 5.6 x 10^−5 T and points in a direction that is 65° below the horizontal. Find the magnitude of the magnetic flux through the top of a desk at this location that measures 110 cm by 62 cm Homework...
  2. S

    Calculating Magnetic Flux from a Solenoid with Given Parameters

    Homework Statement A solenoid 2.50 cm in diameter and 26.0 cm long has 285 turns and carries 12.0 A. (a) Calculate the flux through the surface of a disk of radius 5.00 cm that is positioned perpendicular to and centered on the axis of the solenoid, as in Figure P30.36a. (b) Figure P30.36b...
  3. S

    Magnetic Flux through a hemisphere.

    Homework Statement Symbolic question: Consider the hemispherical closed surface in Figure P30.34. The hemisphere is in a uniform magnetic field that makes an angle θ with the vertical. (a) Calculate the magnetic flux through the flat surface (S1), using pi for π, theta for θ, B, and R as...
  4. R

    How Does Copper Wire Shape Affect Magnetic Flux Density?

    A 1mm-diameter copper wire is shaped into a square loop of side = 4cm. It is placed in a plane normal to a magnetic field increasing with time as \vec{B}=1t\hat{z}Wb/m2. Calculate the magnetic flux density at the center of the loop. I found that the magnitude of the induced current is...
  5. E

    Does Magnetic Force on a Wire Loop Affect Flux Change in a Solenoid?

    Homework Statement Is the magnetic force on the wire loop in a direction tha would tend to increase or decrease the change in net flux through he wire loop.(This situation has a solenoid with current running through it right next to it, the current is being turned on and off.) Homework...
  6. G

    Magnetic flux and emf help?

    The Earth’s magnetic field at a certain location in the UK has a magnitude of 48 μT and is directed at 66° below the horizontal. a)Determine the magnitude of the flux of the Earth’s magnetic field through a wedding ring of diameter 2.2 cm when the ring is held in a horizontal plane...
  7. C

    Magnetic flux density vs magnetic flux

    i'm having trouble distinguishing between magnetic flux and magnetic flux density...can someone please explain to me? also why is it sometimes used interchangeably?
  8. K

    Magnetic flux through the circular cross-sectional area of the solenoid

    Homework Statement A solenoid 1.7 cm in diameter and 30 cm in length has 4000 turns and carries a current of 5 A. Calculate the magnetic flux(in Wb) through the circular cross-sectional area of the solenoid. Since this is a very long solenoid, you may use the simplified magnetic field formula...
  9. T

    Calculating Magnetic Flux Change for Rotating Wire in Magnetic Field

    Homework Statement If a loop of wire starts off horizontal, in a magnetic field angled 12º from the normal to the surface of the loop, and then rotates 180º in a constant magnetic field of magnitude B, what is the magnitude of the change in magnetic flux? Homework Equations Flux = A.B...
  10. A

    Induced EMF in a Pair of Circular Wires with Changing Magnetic Field

    Homework Statement The setup is a pair of two circular wires, a small one of radius b and a large one with radius 2b, both sharing the same center and located on the same plane. There is a magnetic field of strength B within the smaller circle that comes out of the paper towards the observer...
  11. K

    Calculating Voltage in Magnetopause: EMF & Magnetic Flux

    Homework Statement Use the law of electromagnetic induction to deduce what typical voltage would be imposed in the magnetopause by the interplanetary magnetic field, assuming a scale size of the magnetopause of 10Re? Homework Equations -Magnetic flux equation -Faraday's law...
  12. C

    Magnetic Flux of loop holes

    Homework Statement A square loop with resistance 15 ohms is placed perpendicular to a time-varying magnetic field; the loop is 8.2 cm on a side. The magnetic field is changing with a rate of 3.4 x 10^-1 T/s. (a) calculate the rate at which the magnetic flux threading the loop changes...
  13. P

    Magnetic Flux Through an Open Surface: Exploring the Possibility

    Is it possible to have magnetic flux through an open surface ? i mean if there is a circular arc and magnetic field at the centre changes with time then will there be any induced emf in the arc ?
  14. D

    Magnetic flux through a loop near long straight conductor.

    Homework Statement First part of the question: A rectangular loop is placed near a long straight conductor. Conductor is oriented vertically to the XY plain at the origin the loop is contained within the YZ plain. Current passing through conductor. I = 19 Ampere dimensions of the loop...
  15. S

    Magnetic Flux through a loop:

    Homework Statement A single-turn square loop of side L is centered on the axis of a long solenoid. In addition, the plane of the square loop is perpendicular to the axis of the solenoid. The solenoid has 1350 turns per meter and a diameter of 5.55 cm, and carries a current of 2.20A Homework...
  16. M

    Can magnetic flux be surpressed or added to?

    I am studying inductance. Can the core flux be added to or suppressed by the secondary of a transformer. I have been taught that there is only one core flux field. I understand that flux can be squeezed or attracted, I am I correct in stating; a primary current is opposed by a back current...
  17. G

    Minimize Flux Distance X-Axis w/ Magnet Shield

    Is it possible to... Minimize the distance the flux travels in the x-axis from the centre of a magnet. (in 2d representation) Ive attached an cross-section image detailing what I'd like to happen. A "shield" is wrapped around the magnet, leaving only the N and S poles exposed. The flux is...
  18. A

    How do I compute magnetic flux?

    A circular loop (with a radius of 10 cm) rotattes in a constant magnetic fiels, which has a magnitude of 1 T. At an instant when the angle between the magnetic field and the normal axis (to the plane of the loop) is equal to 10 degrees and is increasing at a rate of 20 degrees/s, what is the...
  19. L

    Magnetic Flux Density in a Circular Loop

    Homework Statement A current flows in a circular loop consisting of a single turn.If the same wire is bent into a circular loop of 2 turns and the same current is passed through the loop,the magnetic flux density at the centre will change by a factor of ...? (ans: 4 ) Relevant equations B...
  20. U

    Magnetic Flux passing through loop

    Homework Statement The magnetic field in a certain region is given by B=<40i-18k>T. How much flux passes through a 5cm^2 area loop in this region if the loop lies flat in the xy plane? Homework Equations Flux=B.A The Attempt at a Solution I got the answer (90 * 10^-4) in...
  21. M

    Determine magnetic flux and current

    Homework Equations ? The Attempt at a Solution ?
  22. R

    No Such Thing As Magnetic Flux Density

    I would like to put this out for argument that there is no such thing as magnetic flux density. Since magnetism is a wave like on water's surface, it is continuous. Is there a 'water wave density?" I think not. Unless you mean the distance between wave peaks. But flux lines are only arbitrary...
  23. J

    What is the magnetic flux through the loop

    Homework Statement A 10 cm x 10 cm square is bent at a 90° angle . A uniform 0.050 T magnetic field points downward at a 45° angle. What is the magnetic flux through the loop? Homework Equations Φ = AB cos θ Φ = (pi * r^2)B cos θ The Attempt at a Solution b = .050 T cosθ =...
  24. W

    Does Magnetic Flux Bend When Two Magnets are Taped Together?

    When two magnets are taped together with both north sides touching does the magnetic flux stay in its normal possition or does it bend, if it does in what way does it bend?
  25. A

    Faraday's Law, Magnetic Flux, and the dot product

    Homework Statement We are studying Electromagnetic Induction right now. I understand the concepts, Faraday's Law and magnetic flux. But I don't understand what my book is doing. Homework Equations Magnetic Flux \phi=\intB∙dA Faraday's Law Emf = - d\phi/dt Emf=Electromotive force \phi=Magnetic...
  26. U

    Magnetic Flux & Magnetic Density

    Homework Statement ** What do we mean by saying: A)) The magnetic flux = 3 webber The quantity of magnetism, taking into account the strength and the extent of a magnetic field equal 3 webber ?? is that correct? B)) The magnetic flus density in C point = 2 tesla the amount of magnetic...
  27. T

    Magnetostatics - magnetic flux and energy in toroidal inductor

    Homework Statement A toroidal inductor consists of 500 turns of wire on a ring-shaped core of magnetic material with a relative permeability of 8000. The core has a square cross-section with an internal radius of 20mm, external radius of 40mm and height of 20mm. Find: a) Magnetic flux in the...
  28. C

    Magnetic flux and emf through a rotating ring

  29. L

    Magnetic flux and induction help

    epsilon=-\frac{d \Phi}{dt} where epsilon is the emf. the emf produces a current in the oppostite direction to the loop which gives a magnetic field opposing ther external field B. my notes then say \frac{d \Phi}{dt}>0 \Rightarrow \frac{d \Phi_{Induced}}{dt}<0 but i don't understand this...
  30. M

    Calculate Earth's Magnetic Flux at a Certain Location

    1. At a certain location, the Earth's magnetic field has a magnitude of 5.6x10-5 T and points in a direction that is 72 degrees below the horizontal. FInd the magnitude of the magnetic flux through the top of a desk at this location that measures 110 cm by 57 cm. 2. I used the formula \Phi = BA...
  31. M

    Zero Induced EMF in a Changing Magnetic Flux Loop

    Homework Statement A circular wire loop of radius r= 19 cm is immersed in a uniform magnetic field B= 0.670 T with its plane normal to the direction of the field. If the field magnitude then decreases at a constant rate of −1.2×10−2 , at what rate should increase so that the...
  32. I

    Magnetic Flux through a solenoid

    Homework Statement The magnetic field inside a cylindrical solenoid of area 4 cm^2 is 0.15 T along the axis of the solenoid. What is the magnetic flux through a disk of radius 3 cm placed perpendicular to the solenoid axis? Homework Equations \phi = \zeta B * dA The Attempt at a...
  33. A

    Magnetic Flux Density at different points about a solenoid

    Homework Statement For my physics investigation I am required to first find the theoretical magnetic flux denisty at different points about a solenoid. The points are outside the solenoid: along the axis but past the ends and; perpendicular to the centre of the solenoid but outside. So far...
  34. J

    Magnetic Flux through a bent loop.

    Homework Statement A 10cm x 10cm square is bent at a 90deg angle as shown in the figure. A uniform 0.050T magnetic field points downdard at 45deg. What is the magnetic flux through the loop. Homework Equations Flux= [(Aeff)*(B)]. Flux= [(Aeff)*(B)]*cos(theta). The Attempt at...
  35. C

    Magnetic Flux of Earth onto myself

    Homework Statement Estimate the magnetic flux (due to the Earth's field) through your body (back to front) if you stand facing North. What will be the net change in flux if you turn and face South? Homework Equations Gauss's Law and variants \oint E\bullet dA The Attempt at a...
  36. N

    Magnetic Flux and Induced Current

    Homework Statement The drawing shows a bar magnet falling through a metal ring. In part a the ring is solid all the way around, but in part b it has been cut through. (a) Explain why the motion of the magnet in part a is retarded when the magnet is above the ring and below the ring as well...
  37. R

    Concept of an area vector when finding magnetic flux

    Concept of an "area vector" when finding magnetic flux Hello, I'm currently learning basic Electromagnetic Induction, specifically induced emf in a loop. According to my textbook, magnetic flux is defined as: \Phi = BA cos \theta Given that the field is uniform and is traveling through a...
  38. A

    Determine the base unit for the magnetic flux

    Homework Statement The e.m.f E of a battery is given by E = \frac{P}{I} where P is the power supplied from the battery when current I flows through it. An e.m.f. {E_c} can also be induced in a coil when the magnetic flux, \Phi , associated with it changes with time, t, as expressed by {E_c} =...
  39. N

    Magnetic flux quanta in ground state hydrogen

    How many magnetic flux quanta exist within the ground state hydrogen atom? Thanks in advance.
  40. N

    Finding the Magnetic Flux of a Coil

    See attached problem: http://img72.imageshack.us/img72/4791/65321158jp4.th.jpg The answer is 6.9 × 10−4 Wb - by multiplying the Area by the magentic flux density. Mq is, why does one not multiply this by 850 (number of turns) in order to find the answer. Thanks
  41. C

    How Does Magnetic Flux and Peak EMF Relate in a Solenoid-Coil System?

    A coil is located at the center of a long solenoid of radius R = 15cm which has 5x10^7 turns per meter and carries a current I = 16A. The coil is coaxial with the solenoid and consists of 5 turns of wire each in the shape of a square of length a = 5cm on each side.What is the magnetic flux...
  42. KleZMeR

    Magnetic Flux from Infinite wire

    Homework Statement Infinite wire on Z axis Loop radius a lies in x,z plane, centered on positive x axis, with center a distance b away from origin. Find flux through loop. Homework Equations B field => from the infinite wire, dependent on 1/rho, in the (phi) direction, =...
  43. B

    Inductance & magnetic flux problem -

    Inductance & magnetic flux problem -- please help Homework Statement The magnetic field of a place on Earth has strength 55 microTesla and is tilted 60 degrees below horizontal. A 200 turn coil with diameter 4cm and resistance 2 ohms is connected to a 1 microFarad capacitor. The coil is...
  44. T

    Magnetic Flux, Equator and flying bullets

    Homework Statement At the equator, the earth’s magnetic field is approximately horizontal, is directed towards the north and has a value of 8 × 10^{-5} T. (i) Estimate the EMF induced between the top and bottom of a bullet shot horizontally at a target on the equator if the bullet is...
  45. M

    The Magnetic Flux through a Solenoid

    Homework Statement Find the magnetic flux through a solenoid of length 31.2 cm, radius 1.5 cm, and 610 turns that carries a current of 3.8 A. (in Wb) Homework Equations B_solenoid=u0*N*I/L Flux= B *A The Attempt at a Solution So to find the magnetic field, I plugged the...
  46. M

    Magnetic flux through a disk

    Homework Statement Consider a thin disk normal to the z-axis, of thickness dz and radius p centered on the axis of a dipole. a. Show that 0 = \oint \vec{B} \cdot d\vec{A} \approx (2\pi p dz)B_{r} + (\pi p^{2}) a (dB_{z} / dz), so B_{p} \approx (-p/2)(dB_{z} / dz) b. With B_z for a...
  47. K

    Magnetic Flux and Faraday's Law

    A figure has a 3.0T magnetic field that is normal to the plane of a conducting, circular loop with a resistance of 1.5 ohms and a radius of .024m. The magnetic field is directed out of the paper. The area of the non-circular portion of the wire is considered negligible compared to that of the...
  48. T

    Magnetic flux / induced emf problem

    Homework Statement A single coil with a radius of .02m is placed inside a 3m long solenoid that has 600 turns. The radius of the solenoid is 0.15m. The plane of the coil is perpendicular to the axis of the solenoid. The solenoid is connected to a battery, an ammeter and a switch. The ammeter...
  49. G

    Magnetic flux in a straight wire to a cylinder

    Homework Statement A long, straight wire carrying a current of 3.00 A is placed along the axis of a cylinder of radius 0.500 m and a length of 5.00 m. Determine the total magnetic flux through the cylinder. Homework Equations flux=BAcostheta The Attempt at a Solution i found the...
  50. G

    How Does Earth's Magnetic Field Flux Change with Loop Orientation?

    Magnetic flux! Homework Statement Find the flux of Earth's magnetic field of magnitude 5.00 10-5 T through a square loop of area 40.0 cm2 for the following: (a) when the field is perpendicular to the plane of the loop (b) when the field makes a 20.0° angle with the normal to the...
Back
Top