rajb245
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2 answers
2 votes
9k views
Definition of complex permittivity
4 votes

This is a simple mathematical convenience so that the form of the equation is the same whether or not conductivity is present. The key is to remember the Ampere-Maxwell equation in a homogeneous ...

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4 answers
14 votes
53k views
Transverse Magnetic (TM) and Transverse Electric (TE) modes
4 votes

Notice that there are three equations for the quantities $(E_y,H_x,H_z)$: $$ \frac{\partial E_y}{\partial z} = -i\omega\mu_0 H_x $$ $$ i\beta E_y = i\omega\mu_0 H_z $$ $$ \frac{\partial H_x}{\...

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6 answers
17 votes
25k views
Does ABS shorten stopping distance of a car?
4 votes

Without ABS, an experienced driver will go lighter on the brakes as soon as they feel it lock up. Some time later, he'd press the break again, perhaps not as hard this time. The computer, on the ...

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2 answers
3 votes
4k views
Is the standard explanation for the ring launcher incomplete?
3 votes

Since this is AC powered, I imagine that for one instant in time the current through the solenoid that is creating this changing magnetic flux induces a current in the ring, say, in the CCW ...

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4 answers
5 votes
3k views
Do Electromagnetic Waves really propagate through continuous Induction?
3 votes

Do modern Physicists really think about Electromagnetic Waves in this way? Is this kind of propagation "mechanism" really even needed? I expect there is variability among all the people who study ...

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2 answers
7 votes
6k views
Greens function in EM with boundary conditions confusion
3 votes

Just wanted to add a final point to clear this up for you. The potential of a point charge and the Green's function for your problem are the same, up to the normalization constant. In a comment, you ...

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2 answers
1 votes
10k views
Is there a difference between correlation processing and matched filter processing?
Accepted answer
2 votes

I believe OP is asking about the matched filter of signal processing, and another implementation called a correlation receiver. I believe this is off-topic on this site, but I'll keep you from having ...

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3 answers
2 votes
407 views
Notation of plane waves
1 votes

"Space-dependent phasor" makes some sense. Electrical engineers will often just say that's the "complex amplitude of the time-harmonic field" or "time-harmonic phasor".

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9 answers
49 votes
97k views
Why does wavelength affect diffraction?
1 votes

The interference between all the rays emitted from the aperture to a fixed point on the screen can be constructive or destructive, depending on the various path lengths involved (measured in ...

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3 answers
10 votes
2k views
Polarization of the lowest mode of a Gaussian beam
1 votes

The Gaussian beam is a model of physical beam propagation (not even one that exactly satisfies Maxwell's equations at that, although it does satisfy certain paraxial approximations of the equations). ...

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3 answers
1 votes
3k views
2 solenoids: emf and frequency
1 votes

Aside from the mutual coupling between the solenoids, the primary (the one you are driving) will be highly inductive to the driving circuit. If nothing else, beyond some point, as you increase the ...

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3 answers
4 votes
305 views
How does one determine whether an object will make an EM wave refract in a qualitative way?
1 votes

From one engineer to (I suspect) another, I'll give you my practical perspective in this largely theoretical forum. If you're talking about radio refraction by objects in the real world, the "back of ...

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2 answers
0 votes
5k views
Frequencies of Matter
0 votes

Although the OP is asking what seems like a metaphysical question, he or she might be on to something. If there were a theoretical material that did not get destroyed by physical vibrations in the ...

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3 answers
11 votes
620 views
Magnetic scalar potential far above a magnetic film
0 votes

The field you are interested in is always calculated as some derivative of the potential. I don't have Jackson handy, but I'm guessing in the magnetostatic case, you take ${\bf H} = -\nabla \Phi_M$ ...

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5 answers
11 votes
15k views
How can the nucleus of an atom be in an excited state?
0 votes

While it may be easy to visualize electrons "jumping" up to a higher orbit with another discrete energy level, using that analogy doesn't help grasp the concept of excited nuclei. Instead, think of ...

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