All Questions
9
questions
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
5
votes
2
answers
4k
views
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'...
- 215
2
votes
3
answers
5k
views
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
1
vote
1
answer
861
views
Electric field of uniformly moving charge ; misprint in Feynman textbook? (28.3)
I doubt about formula (28.3) from this Feynman's lecture.
$$\textbf{E} = - \frac{q}{4 \pi \epsilon_0 } \Big{[} \ \frac{e_{r'}}{r'^2}+ \frac{r'}{c} \frac{d}{dt} \Big( \frac{e_{r'}}{r'^2} \Big) + \...
- 115
5
votes
1
answer
545
views
Why do planets not radiate EM waves in their orbits?
Despite being overall near-netural, I would expect the individual electrons and proton to radiate long EM waves as we accelerate around the Sun or rotate around our poles. Is the acceleration so small ...
- 163
1
vote
3
answers
13k
views
Deriving the wave equation for electromagnetic waves
I'm currently referring to the wave equation derivation given in "Introduction to Electrodynamics" by David J. Griffiths. It follows something like this:
The electromagnetic wave equations are given ...
- 87
5
votes
2
answers
5k
views
Force on Earth due to Sun's radiation pressure
I have been asked by my Classical Electrodynamics professor to calculate the force that the Sun exerts in the Earth's surface due to its radiation pressure supposing that all radiation is absorbed and ...
- 727
2
votes
1
answer
1k
views
Confusion even over such a simple application of the Right-hand rule to determine direction of magnetic field
After reading this question on this site I learned that the direction of the magnetic field is given by $\boldsymbol{B}=\frac{1}{\omega}\boldsymbol{k}\times \boldsymbol{E}$
The left diagram below is a ...
- 295
1
vote
1
answer
248
views
Derive the form of the fields for TEM waves in a waveguide
In my book it says that for TEM waves in a waveguide, with: $$\textbf E = \textbf E_0(x,y)e^{i(kz-\omega t)}$$ and $$\textbf H = \textbf H_0(x,y)e^{i(kz-\omega t)},$$ where $z$ is the direction of the ...
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