Recent content by ednobj

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    EM waves amplitude's effecting penetration?

    Generally, yes but the extent to which it happens or is possible depends largely on the material considered. For a conductor, check out the concept of skin depth.
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    A charged conducting wire in an electric field

    First off, you would definitely need to know the geometry of this wire. Next, the beauty of working with conductors is the ease of the principle of superposition. Basically, solve the problem of the wire without net charge and the electric field and the problem of a non-neutral conductor wire...
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    Question on TEM representation used in Griffiths book

    So, the real part of 9.17 is: \\ \Re(\tilde{f}) = \hat{x}\left[\Re(\tilde{A})\cos(\omega t - kx) + \Im(\tilde{A})\sin(\omega t - kx)\right]. The above is general solution to the homogeneous wave equation for a single wave traveling in the +z-direction. The sign in front of the sin term...
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    Find Parallel Polarized E Field Reflection Direction

    You know from reflections that \hat{n}_r=\hat{x}\sin(\theta_i)-\hat{z}\cos(\theta_i) If your E-field is in free space, it must be normal to this outgoing wave vector. Since you had a parallel incident E-field, there are only two possibilities and one is just the negative of the other. Which...
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    How much charge is there on an conductor

    Um...http://hyperphysics.phy-astr.gsu.edu/hbase/tables/fermi.html#c2. A simple google would've shown that the numbers are fine and the energy is right within an order of magnitude. I really think you're just getting confused with definitions. In E&M, we start by defining an ideal case of...
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    How much charge is there on an conductor

    To give you an example of how much energy it takes to come close to depleting a conducting material of it's internal mobile charge, consider a 10cm ^3 block of copper (this is a relatively small bit of copper, actually). Copper has a free electron density of 13.6*10^9 C/m^3 remembering that 1...
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    How much charge is there on an conductor

    tiny-tim is right. If all the free electrons of a conductor were at one end, the localized charge and thus the corresponding energy of the configuration would be absolutely enormous. The energy required would strongly hinder anyone trying to attempt to create a field that strong. This is...
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    Infinite grounded plane induced surface charge

    If you reread the quote you took from my response, you will see that I never contested that E=0 in a perfect conductor; I said below. The *more* that needs to be known about the conductor is how thick it is because outside this thickness, there can certainly be a field.
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    Infinite grounded plane induced surface charge

    The equation \nabla^2 V = 0 does not say that there is no electric field in a region. Remember that a point charge satisfies that same equation everywhere except for at the point charge but the electric field is pervasive. If one were to construct an infinite, neutral, conducting plane and...
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    College Concerns: What Should I Expect?

    The last list was given for graduate schools. Keep in mind that those rankings may or may not apply for the respective schools' undergraduate curriculum. There are other things to consider that are not purely academic. For instance, at Mass. Inst. of Tech., students in Nuclear Engineering...
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    How Is Magnetism Propagated and Poles Distinguished?

    Photons are the carriers of electromagnetic field but you have to consider the fact that when EM waves are observed on any macroscopic level, that wave is made of an incredibly large number of photons. What we observe is the averaging over of them in time and space. Particle-like carriers of...
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    Help understanding electromagnetism (fields and radiation)?

    The electric and magnetic fields are two separate, distinct fields created by stationary and moving charges. One can set up only electric fields or only magnetic fields in static cases where these fields do not change in time. When time is considered, Maxwell's equations must be used and they...
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    From voltage to electric/magnetic fields

    Saying there's a DC voltage just means that the voltage does not change sign with respect to its reference point, e.g. typically your ground. If you truly have V = V(t,x), then your electric field and, by Ampere's Law, your magnetic field will have time dependence. So for a general V =...
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