All Questions
55
questions
1
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1
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61
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Charge affected by EM-pulse. What is the equation of motion?
I'm studying for my test on radiation for Tuesday. I came across this exercise. Thought it looked interesting but now I'm stuck and I can't move forward before I finish this one.
Exercise:
A ...
- 35
0
votes
0
answers
134
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Gradient of Greens function
This question is about Jackson's equation (10.75) and (10.77) I don't know the step in between these two equations.I'm not sure what our unit vector $n'$ will be here and how can we take gradient of ...
- 385
1
vote
1
answer
294
views
How do integral representations of $\mathbf A$ and $\Phi$ satisfy Lorenz condition?
The following are the integral solutions of the potentials, obtained from the retarded potentials (by a Fourier transform):
$$\mathbf A (\mathbf r) = \frac{\mu_0}{4\pi}\int_V \frac{\mathbf J (\mathbf ...
- 903
-3
votes
2
answers
7k
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How to determine the angular velocity of a particle with mass $m$ and charge $q$ in a constant B field? [closed]
$\textbf{PROBLEM:}$
A particle with mass $m$ and charge $q$ moves in a constant magnetic field $B$. Show that, if the initial velocity is perpendicular to $B$, the path is circular and the angular ...
0
votes
2
answers
147
views
Wave number of $\mathbf{E}$ field
If I have an $\mathbf{E}$ field:
$$ \mathbf{E}_1 = x E_0 e^{-j(y-z) } $$
I think I can find its wave vector direction by finding the $\mathbf{H}$ field and then solving for the Poynting vector $\...
- 143
14
votes
4
answers
5k
views
Why are EM plane waves transverse?
I was reading Griffiths' Introduction to Electrodynamics, specifically Section 9.2.2 on plane waves. I can see that if we want a transverse wave traveling in the $z$ direction that we are only going ...
- 561
1
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0
answers
277
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Question about "quadrupole radiation" vector potential formula derivation
I tried to get an expression for $\mathbf A (\mathbf x )$ in quadrupole approximation. After some transformations of Liénard–Wiechert vector potential I got, as in many books,
$$
\mathbf A \approx \...
user8817
2
votes
3
answers
5k
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A charged sphere with pulsing radius
Radius increases and decreases periodically (as a pulse).And so does the charges on the surface of sphere.
I can't get what is gonna happen.the EM waves are produced perpendicularly to motion of the ...
- 2,479
5
votes
2
answers
5k
views
Force on Earth due to Sun's radiation pressure
I have been asked by my Classical Electrodynamics professor to calculate the force that the Sun exerts in the Earth's surface due to its radiation pressure supposing that all radiation is absorbed and ...
- 727
5
votes
2
answers
4k
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Make a semi transparent mirror with copper
The question:
How would you make a semi transparent mirror (50% reflection, 50% transmission) with glass with a layer of copper. For light $\lambda$ = 500nm Try to be as realistic as possible
What I'...
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