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  1. zero magnetic flux in the transformer core when there is a short circuit in the secondary

    Hello All.


    if the secondary current of the transformer produces a current flow that opposes the initial field (lenz's law). Why is not a zero magnetic flux when there is a short circuit in the...
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    I think laplacian talk about the causes of the...

    I think laplacian talk about the causes of the vectors and scalar field. In that case it says that the cause of the gavitational potential is the mass density. For the

    {\nabla}^{2} V =...
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    with the expresión

    \nabla (\nabla .A) - \nabla \times \nabla \times A

    the first term of the equation is the gradient of the divergence. So it is a vector whose magnitude is the rate of...
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    Laplace operator

    I am studying electromagnetism but there is a concept that can not lead to the interpretation and it's Laplace operator o laplacian.

    {\nabla}^{2} A = \nabla (\nabla . A)- \nabla \times \nabla A ...
  5. Thread: Unit Jy

    by julian403
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    883

    So, a [Jy] it's one watts in one metter square...

    So, a [Jy] it's one watts in one metter square for a frecuency of one hertz. If we have a radiation of 250 [Hz] which have 2.50 [W/m^2], so

    \frac{2.50}{250}=0.01 [Jy]

    Thats correct?
  6. Thread: Unit Jy

    by julian403
    Replies
    4
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    883

    Unit Jy

    The Jansky unit. It's a unit for intensity ? or for energy? Because Jy = W {m}^{-2} {Hz}^{-1} = W {m}^{-2} T
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    Thanks. And Assuming that the primitive planet...

    Thanks. And Assuming that the primitive planet got an m mass and it's descibing an orbit. If in the future the planet get more mass. It will take a lower orbit or may increase the tangential velocity...
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    The beggining of the planet orbit

    Why the planets describe an orbit around the star? Yes, I know gravitational force acts as centripetal force. And there is

    \dst {m}_{p} \frac{{v}^{2}}{r} = G \frac{{m}_{p}{m}_{s}}{{r}^{2}} ...
  9. So, the definition of volt is still the derivate...

    So, the definition of volt is still the derivate of amperio. But, Why using a new patron like Josephson junction will changes some value of SI, like {\mu}_{0}
  10. whay do you mean with it's now defined as...

    whay do you mean with it's now defined as traceable to frequency.
  11. Thanks. And other question. Why is define like...

    Thanks. And other question. Why is define like fundamental the current and not the carge? I think that is practical way. It's really dificult measure charge?
  12. Definitions of volt using SI's fundamental magnitude

    I need help with the definition of volts. We know that the ampere is the unique electric fundamental magnitude in SI system. And It's define like:



    So, how can we define volts? Becuase we...
  13. I read the page. \dst {W}_{average} =...

    I read the page.

    \dst {W}_{average} = {V}_{rms}{I}_{rms}

    I can measure the \dst {W}_{average} measuring voltage and current with the multimeter because this are rms. But in this case it would...
  14. Average, apparent and real power. I'am confused

    the average power known as rms is the power used in an interval of times that it consume the same power as a continuous signal.

    {P}_{rms} = \frac{{V}_{p}}{\sqrt{2}}\frac{{I}_{p}}{\sqrt{2}}= VI ...
  15. Thread: Electric arc

    by julian403
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    967

    thanks

    thanks
  16. Thread: Electric arc

    by julian403
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    967

    So, suppose that average distances of the clouds...

    So, suppose that average distances of the clouds to land is 2000 meter, with it we can calculate the diferential of potential of a ray.

    \dst 3 [ \frac{MV}{m }] *2000 [m] = 6 [GV]

    And,...
  17. Thread: Electric arc

    by julian403
    Replies
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    967

    Electric arc

    An electric arc is generate when an electric field exceeds the dielectric strenght of the medium? For example if i wanna make an electric arc I must put 30 [KV] in one centimeter? In the air of...
  18. Outside magnetic field for Solenoid using Ampere's law

    Using Ampere's law for a solenoid, We can see here Solenoid - Wikipedia, the free encyclopedia that the magnetic field it's

    216

    \oint \vec{B} d\vec{l}={\int}_{A}^{B} \vec{B}...
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    distance between dielectrics

    I have the next problem:



    212

    What I did is: First I calculated the carge in the in the inner sphere

    \dst q= 20[\frac{Kv}{ m}] 4 \pi 6 {\varepsilon}_{0} {(0.01[m])}^{2}=1.33 [nC]
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    thanks, but I'm still confused. Why Radiation...

    thanks, but I'm still confused. Why Radiation pressure is a necessary consequence of momentum conservation? Because when a body increase the temperature, the momentum is conserved too. Adding all...
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    radiation pressure

    There are two phenomena when an Electromagnetic wave on a body inside, one is an increase of temperature and the other is radiation pressure.

    \dst T= \sqrt [4]{\frac{I}{\sigma}} and Pr =...
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    Electric displacement density

    I always had a doubt about electric displacement density \vec{D} which it's electric displacement/surface.

    D=\frac{\psi}{S}

    first of all
    \psi is electric displacement and, this is an other...
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    thanks, but the direction of magnet fields are...

    thanks, but the direction of magnet fields are diferent in coils 1 and 3 than 2 and 4 and the variation of flow wil be opposite so potential will be opposite in these coils. That's my doubt. Or...
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    Electric generator

    I'm wanting to do an electric generator. Seerching I found the design easier. Magnets must necessarily be in the rotor to not use brushes or coals.

    172

    tTe principle of generator is

    \dst...
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    thanks for the answer, let me see if i got it. A...

    thanks for the answer, let me see if i got it. A system can make a lot of path, at least are the potential paths. When i find with the langranian the path which minimizes the energy, this is the real...
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