Recent content by John94N

  1. J

    A Determination of Extraordinary Waves By Plasma

    I have been trying to find a method to predict the polarization effects of a plasma with a B Field on low frequency waves. From Chen's Intro to Plasma Physics and Fitzpatrick's Plasma Physics I understand the development of the dielectric tensor and calculation of dispersion with the B field but...
  2. J

    Understanding Non-Conservative Fields in Faraday's Law - Explained

    Thanks for the responses. The videos from Dr Lewin's lecture really hurts my head, but they explain a lot. Thanks, John.
  3. J

    Understanding Non-Conservative Fields in Faraday's Law - Explained

    Jolb, thanks for your response. i guess I was not considering the total B field in Faraday's law, that is the B field generated by the source and that generated by the ring itself. Thanks John
  4. J

    Understanding Non-Conservative Fields in Faraday's Law - Explained

    This has been bothering me for a while. Consider a varying magnetic flux through a closed loop. Faraday’s law says the integral of E around the loop is V. This seems to be OK if the loop itself is split and joined with some resistance and with a voltmeter we measure across the resistor. However...
  5. J

    Calculating Self-Inductance of Long Current-Carrying Wire

    iitjee10, Not an easy problem. I think there is a problem in your third equation which says that flux is linearly proportional to z. Finding the inductance of a straight length of wire is complex. Here is a reference http://www.ee.scu.edu/eefac/healy/indwire.html. Good luck.
  6. J

    Induction motor starting direction

    That's makes sense. Thanks.
  7. J

    Induction motor starting direction

    I have a question on induction motor starting direction. I understand the phase delay between the running winding and starting winding, but I don’t see why an induction motor should start in the same direction each time. Is there a directional bias on the stator or rotor coils that ensures the...
  8. J

    Question on Poynting Vector calculation in wire.

    Sorry to get hung up on this but if current flow is defined as positive charges then current on a wire in +z has E in +z. By right hand rule H is clockwise around wire and then E X H, right hand rule again, must be out from wire, which must be wrong but I don't see why.
  9. J

    Question on Poynting Vector calculation in wire.

    If electric field vector is positive at the tip and negative at the base then positive current must flow from tip to base or in reverse direction to E. Correct? This must be so if EXH is in the minus r direction.
  10. J

    Question on Poynting Vector calculation in wire.

    I think the energy from H and E is flowing into the wire is equal to the power dissipated as heat from I squared R flowing out from the wire, think of an incandescent bulb
  11. J

    Question on Poynting Vector calculation in wire.

    Right because I is flowing in -z direction. Thanks.
  12. J

    Question on Poynting Vector calculation in wire.

    I must be missing something here in a sign, but doesn't crossing E into H here result in the Poynting vector out from the wire?
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