Eddy currents Definition and 71 Threads

  1. W

    Eddy currents and current induction questions

    Homework Statement A solenoid is connected to a power supply and a ring of metal is sitting on top of the solenoid. When the power supply is turned on the ring jumps up off the solenoid. a) Suppose that when you look down at the solenoid from above. The current due to the power supply is...
  2. T

    How Do Split Brake Discs Affect Eddy Currents and Braking Force?

    Hey guys, the other day i was reading about eddy currents and it was getting intersting, except i had a few questions going through my mind that i couldn't find answers to and wanted to ask: say we have a circular bit of aluminium which is our brake disc and an electromagnet which induces the...
  3. B

    How Do You Calculate Eddy Currents in a Circular Petri Dish?

    Homework Statement I am doing undergraduate research in a Biomedical Engineering Lab. We are working on nervous tissue engineering and looking at how different stimuli effect nerve growth. I am struggling with some of the physics. I am wondering if anyone could teach me how to calculate or...
  4. P

    Why Do Eddy Currents Form Circular Loops?

    i know i haven't understood the concept of eddy current and that is why i am posting this question: why are EDDY currents CIRCULAR (why form a loop in circular form)? please also explain this answer that statement that i found on : http://wiki.answers.com/Q/What_is_an_eddy_current "When...
  5. P

    Unraveling the Mystery of Eddy Currents

    i know i haven't understood the concept of eddy current and that is why i am posting this question: why are EDDY CURRENTS circular?
  6. L

    Eddy currents due t into the core of the Earth

    Hello, Those days I wonder if the magnetic field from the Sun, could make the Eddy's currents inside the core (ferromagnetic) of our planet, because of the rotation of the Earth. (like a induction cooker) It would result a magnetic field on the Heart, and if the magnetic field from the Sun...
  7. G

    Difficult problem about eddy currents and terminal velocity

    Hey guy, Ive been recently investigating the phenomena of eddy currents, particularly that of a magnet falling down a copper tube. To the people who haven't seen it before, basically the magnet reaches terminal velocity in the copper tube extremely quickly, and takes a long time to leave the...
  8. G

    How Can Eddy Currents Be Used for Energy Recovery in Locomotive Braking Systems?

    I have read that locomotives use eddy current braking systems, and one article mentioned that this system has also been used to charge batteries in a recovery circuit. However, I can not find details on this idea. From what I understand, the train has conducting discs attached to the wheels, and...
  9. E

    Eddy Currents: Understanding Lenz's Law

    I don't really understand what is eddy current. Is it just the current that is formed using Lenz's law? Or is it different? My idea of eddy current is that it is of many small swirls all over a metal plate that opposes the force exerted to move the plate. Thank you.
  10. A

    Eddy Currents in Magnetic Fields: Copper/Aluminum vs Iron

    Homework Statement It is given that when a copper or aluminium bar is set in oscillation in a magnetic field eddy currents are produced inside the bar. Should it be necessary that the bar should be made of a non-magnetic substance such as copper, aluminium etc.? Can it be a ferromagnetic...
  11. A

    Eddy currents and the motion of the body

    A solid metallic body moves closer to a magnet. This causes increase in magnetic flux linked with the body. Eddy currents are generated in it. Now, the problem is: will the body come back to its original position or will stay there? I say that eddy currents will generate heat which will go...
  12. G

    Foucault currents / Eddy Currents vs material selection

    Hello, I am a mechanical engineer by education and I am working on a multi disciplinary problem. I regularly work with eddy current dynamometers at work and I am curious about the materials used within the rotor and stator of these dynamometers. First off, this isn't a homework problem per...
  13. R

    Are Eddy Current Forces Always Opposing Motion?

    Hello, I'm not sure where to post this so I hope this is the right spot. It's not a homework question, just a concept I need to get straight before an exam ;) If I'm pulling a sheet of metal through a uniform magnetic field (which is perpendicular to the sheets motion), Eddy currents are...
  14. D

    Understanding Eddy Currents: Causes, Effects, and Mitigation

    Okay so i just want to make sure i got this right because its a kind of confusing topic for me. So eddy currents are caused because when there is a motion (with a conducting surface) through a magnetic field a current is induced? and because there is a current there is also a magnetic field due...
  15. C

    Solving the Eddy Currents Problem with a Pivot Pendulum

    Hi All! I am working on the Eddy Currents problem. I was to set up the problem and derive some equations for the pivot pendulum with Eddy currents. Please see attachment. As you see the pendulum swings between max point ( just outside the B field) and enters the B field and then...
  16. C

    Is Induced E.M.F a Force? Understanding Eddy Currents

    1. Is it induce e.m.f is a force? 2. What is the eddy current?
  17. O

    Calculating/estimating Eddy currents due to B-field

    Its been 15+ years since I have done any calcs like this and am very rusty, so even just a pointer in the right direction would be really appreciated... I need to calculate/estimate the magnitude/value (IF any!) of eddy currents that would/could be generated in an ultra high speed rotating...
  18. E

    How do I calculate the torque of an eddy current brake?

    Homework Statement An electromagnetic "eddy current" brake consists of a disc of conductivity \sigma and thickness d rotating about an axis passing through its center and normal to the surface of the disc. A uniform B is applied perpendicular to the plane of the disc over a small area a^2...
  19. K

    Eddy currents are causing major delay and attenuation

    Hello everyone. I am trying to measure the position of a magnet moving inside a steel tube using a magnetic sensor on the outside. Eddy currents are causing errors due to phase shifts and amplitude changes. Any ideas? Can eddy currents be re-directed using selective copper paths? Since eddy...
  20. J

    How Do Eddy Currents Form in Transformers?

    someone knows how eddy currents in transformers are produced? by friction , resistance or heat transfer? i mean the classical example is the wheel that is braked between the poles of an electromagnet, but how this applies to a transformer where there is exactly the opossed, a fixed conductor...
  21. M

    Why Doesn't Gold Work for Jumping Rings?

    Guys & Gals Everyone has seen the jumping rings demonstration…. Aluminium works fine, so does silver, iron and steel just stick to the coil Cut slots or drill holes in the disks and you get what you would expect BUT… Why doesn’t gold work? Cheers Mike
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