Tagged Questions
2
votes
3answers
78 views
Radio antennas that are much shorter than the wavelength
From my limited experience with ham radio when I was a kid, I expect transmitting and receiving antennas to have lengths that are on the same order of magnitude as the wavelength, and in fact I recall ...
1
vote
0answers
108 views
How does a Fresnel rhomb work (half and quarter wave plate)?
How does a Fresnel rhomb work (half and quarter wave plate)?
I am aware of birefringence, which creates a phase shift of $\Delta\phi=\dfrac{2\pi\Delta nL}{\lambda_0}$. But this doesn't explain how a ...
2
votes
3answers
943 views
Some questions about car radio and cellphone antennas
1-Why the antenna of the radio of cars is located outside the car and not inside?
2-If the answer to 1 is because that cars are like Faraday cages then how come my cell phone can receive signal ...
5
votes
2answers
545 views
What is the minimum wavelength of electromangetic radiation?
As a first approximation, I don't see how a wavelength of less than 2 Planck distances could exist. The question is: are there any other limits that would come into play before that?
For example:
...
2
votes
3answers
306 views
Does the wavelength always decrease in a medium?
I was studying a GRE Physics Test problem where optical light with a wavelength of 500 nm travels through a gas with refractive index $n$.
If we look at the equations for wave motion and index ...
