All Questions
Tagged with radiation electromagnetism
110
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What happens to the electric field in an accelerated capacitor?
Say we have a charged capacitor with some charge $Q$ in one of its plates (and of course the opposite charge on the other plate). It is a well-known result that the electric field inside this ...
- 1,616
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32
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Radiation due to charge particles
We know that accelerated charged particles emits em waves/energy.When we apply voltage across a conductor the electric field applies force on the electrons then why don't the electrons in the ...
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2
answers
70
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Why is radiation power defined at infinity?
According to Griffiths in chapter 11 , given a source of radiation enclosed by a sphere, the power passing through the sphere is
$$ P(r) = \oint \mathbf{S} \cdot d\mathbf{a} = \frac{1}{\mu_0} \oint (...
- 449
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Electromagnetic radiation exposure power density per wavelength
Does anyone know a theoretical study or an experimental study of the electromagnetic ambient power density at different wavelengths? To ask simply, how much electromagnetism are human usually exposed ...
- 125
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2
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71
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Radiation through optical windows
Edit: I have tried answering this a different way since posting this, see my newer answer below.
Problem I'm interested in solving: How much radiative heat load is entering the system through optical ...
- 31
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2
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530
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Why doesn’t Bremsstrahlung occur in simple flows of electrons?
From what I have read, bremsstrahlung is caused by electrons loosing kinetic energy when being decelerated by another charged particle. The lost energy being converted into radiation.
So why isn’t ...
- 71
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67
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Paradox in the observation of ripple
What I am going to speak about may not be a paradox but i see a contradiction here so I used used the word "paradox". To begin with, let there be 2 charges A and B which are stationary with ...
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Is the Sommerfeld radiation condition equivalent to the requirement that the Poyting vector points outward?
In the context of classical electromagnetism with spatially bounded time-varying sources $J(x)$, the usual boundary condition that we impose at spatial infinity is the Sommerfeld radiation condition
$$...
- 48.4k
4
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How to compute the magnetic vector potential in the radiation zone due to a charge density from Thomson scattering?
Context
In the course of studying Thomson scattering, I obtained a current density described by the equation
\begin{align}
\mathbf{j}(\mathbf{r},t)
=&
\frac{ e^2\,E_\text{inc}}{ m\,\omega}
\,
...
- 460
-1
votes
1
answer
69
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Interpretation of watts per square meter for intensity of radiation
The energy that an electromagnetic field can deliver to a system is proportional to the square of the field. However, we use the terminology watts per meter square to represent the amount of energy ...
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2
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34
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Multipole radiation of a wave
I read that a sound wave (a scalar wave) produces monopole radiation, an eletromagnetic wave (a vector wave) produces dipole radiation, and a gravitational wave (a second order tensor wave) produces ...
- 687
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113
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Compton Scattering Notion
I have been reading about Compton Scattering and got confused about exact technicalities. So forgive me if I ask multiple questions, but all related to each other. This is due to the fact that you don'...
- 367
2
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1
answer
77
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Simulating $e^-\rightarrow e^-\gamma$ scattering in QED
Is there any physical reason/symmetry prohibiting me from studying the $e^-\rightarrow e^-\gamma$ interaction? Because I haven't seen any QFT textbook dealing with such a simple process. It is the ...
- 3,992
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1
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59
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Accelerating charges [duplicate]
Considering the fact that accelerating charges radiate, thereby losing energy and magnets are made up of tiny dipoles that consist of spinning electrons, why doesn't the magnet radiate and eventually ...
- 49
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788
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How do non-periodically varying currents produce electromagnetic waves?
Electromagnetic radiation is created by the varying/accelerating of a system of charges and currents. Suppose that the time dependence of the charges and currents are $\rho(x,t)$ and $J(x,t)$. Then ...
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