All Questions
Tagged with electromagnetic-radiation conductors
40
questions
2
votes
1
answer
396
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EM-wave equation in conductors with source terms
The traditional modified Maxwell's equations to express em wave inside conductors that I have come across are:
$$
\nabla\cdot\mathbf E = 0
\\\nabla\cdot\mathbf B = 0
\\\nabla\times\mathbf E = -\frac{...
- 6,636
2
votes
1
answer
529
views
Do induced currents in a conductive surface result in significant electromagnetic fields outside the surface?
Consider the situation of a plane electromagnetic wave in vacuum incident normally on an interface with a good conductor. Within the conductor there is a small transmitted electric field (proportional ...
- 133k
3
votes
1
answer
618
views
Electric and magnetic fields boundary conditions
For a perfectly conducting and perfectly dielectric interface, I understood that tangential component of electric field is zero and continuous. But I have read that the normal component of magnetic ...
0
votes
0
answers
22
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Effect of an electromagnetic field on an open metallic body
I have read on my book (I do not put its title since it is not in English) the following sentence about a metal body which receives an external electromagnetic wave (with Js we mean its current ...
- 1,319
1
vote
0
answers
484
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Coaxial cable and faraday cage: why those shielding properties precisely?
The magnetic field produced by a coaxial cable outside of the outer shell is $0$. Indeed, integrating $\nabla \times \mathbf{B}=\mu_0 \mathbf{j}$ along a circle outside the outer shell, the inner ...
- 1,450
0
votes
3
answers
377
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Electromagnetic waves in a conductor
I am trying to understand the solution for electromagnetic plane waves in a conductor. I understand the derivation of the wave equation:
$$\nabla^2 \boldsymbol{\mathrm{E}} = \mu\epsilon \frac{\...
- 2,122
0
votes
1
answer
111
views
Are these forms for effective permittivity equivalent?
I was browsing through a book and noticed the following form for effective permittivity (Eq. 1.14.2 of this book):
$$\epsilon(\omega) = \epsilon_d(\omega) + \frac{\sigma_c(\omega)}{j\omega}$$
...
- 221
0
votes
1
answer
206
views
Perfect Electric Conductor with applied voltage source
Let’s consider a perfect electric conductor which is connecting the terminals of an ideal voltage source (it is a short circuit in practice). What happens from an electromagnetic point of view?
We ...
- 1,319
1
vote
1
answer
111
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Conductors and non-optical photons
While there seems to be plenty of information available about the photoelectric effect and the emission and absorption of photons by conductors (metals) at optical frequencies, I’ve been searching for ...
- 11
2
votes
2
answers
423
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Why are 'low frequency' EM waves attenuated by a single layer of kitchen foil?
Can someone explain why my am radio doesn't work when covered by a layer of foil that is less than one 'skin depth' at the appropriate frequency?
According to wikipedia and other websites on the ...
- 57
2
votes
1
answer
2k
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Skin Effect Explanation
I do not understand some things about the Skin Effect.
Its Wikipedia definition is:
Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor ...
- 1,319
0
votes
0
answers
140
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Do conductors reflect Wifi signals? If so why?
I know electric field can't pass through conductors, but I have seen people surround their wifi router by soda can (not entirely) for better signal strength. I want to know what really happens there.
0
votes
1
answer
2k
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Difference between bound and free charge/current in a perfect conductor
For the case of charge, it seems clear that in a perfect conductor the free charge refers to the excess charge that has been dumped into the conductor, while the bound charge refers to the charge that ...
- 3,514
1
vote
2
answers
2k
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Is there a way to make infrared pass through metals?
I am curious to know a way that will make infrared pass through metals. Metals are good reflectors of infrared,can we manipulate the wave in order to make them pass through metals?.
user197535
3
votes
1
answer
164
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How do you tell whether charges oscillate in the antenna because of an electric or magnetic field?
The electrons in a receiving antenna oscillate, can we establish if they respond to an electric or a magnetic field?
How can we know if there is an electric field apart from the one caused by the ...
user137879