Borber
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No.
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I give up, this makes no sense because you don't read answers.
A radio to receive 1000m wave length station must be long 1000m or high 1000m or wide 1000m to satisfy your metaphysics philosopher needs. All electronics science belongs to physics. Learn about abstract thinking.
Normally one can ignore transmission line effects if the length of the path is <10% of wavelength.
When wavelength is 1/4 wave or any odd harmonic, load impedance appears inverted at source.( e.g. open = short)
When not a perfect transmission line, it is usually dominated by L & R, so lumped model applies for signal path d, d istance < 10% of Lambda, where RLC have incremental values that depend on cable type.
BTW Electrons don't flow at the speed of light down a wire, , however the wave approaches this speed ( usually 2/3 due to dielectric). The wave is like a domino effect of electron collisions that occurs at this speed while actual electron migration is very very very slow. ElectroMigration is not the relevant part of analysis in RF propagation effects and more a concern to corrosion diffusion and aging.
360° x 1000/1000=360° when two points that are 1km away.how do you Justify this Case?
Yes, quite right.
do you agree below Sentence?? I agree
((But at low frequency 300kHz = 1km wavelength, the difference in phase between two points that are 50cm away is only 360° x 0.5/1000 = 0.18° and there is almost no voltage difference.))
360° x 1000/1000=360° when two points that are 1km away.how do you Justify this Case?
i justify when electron domino charge reach 1km lenght the period full sine wave complete.
Hi linuscomex,
All wave motion (let's simplify to a simplistic, one dimension system) can be described as a function of x + v*t, where x is a spacial variable, v is the velocity of the wave and t is a temporal variable.
A sinusoidal wave can then the described as A*sin(x + v*t), where A is just the amplitude of the wave.
Therefore, you have a choice: you can either describe the wave as a function of space (x), which is what you seem intent on doing, OR you can describe in in terms of time (t), OR both!
Inside a circuit, at low (electrically small) frequencies, we tend to describe waves in terms of time, but the most thorough results are achieved by describing both, which is generally how "RF" engineers operate. No one really describes waves in terms of space (unless resonances are involved), which is what you are doing.
However, they are all equivalent.
To answer your question, a 360 degree phase shift could also be related to points in time. At 1 Hz, If we look at a single electron in the circuit, 360 degrees simply corresponds to a period of one second.
You are not talking about a circuit; you are talking about a photon travelling at the speed of light in inbounded, free space. Of course, in this case, you are correct!
thanks bro.
do you agree the 300 khz sine wave need 1 km wavelenght to complete one period????
View attachment 118909
do you agree the 300 khz sine wave need 1 km wavelenght to complete one period????
In general? No.
In free space? Yes.
Dispersion engineering is the engineering of artificial media in which the wavelength can be set to (within reason) any desirable value. I could (in theory) develop a periodic medium in which the wavelength was 1mm at 300 kHz. (this is unrelated to your question, but one needs to consider such cases for a good understanding of the topic).
A circuit is not free space. Wavelength only has meaning in a specific context. In this case, you are trying to apply a concept from free space propagation and force it to work in a circuit, which obviously does not have the same bounds as free space.
Velocity is only speed of light in a vacuum or air
VF = k*c = where k is the reciprocal of the square root of the dielectric constant (relative permittivity) of the material through which the signal passes:
Typically VF= 2/3c ~ 0.7c
otherwise you are close
300kHz sine wave needs 1/300000 s in time to complete one period. No length is needed.
Your picture of travelling electrons is wrong, and you confuse yourself. The electrons move one direction during half the wave period, and then polarity and current direction changes in the other half period. Now electrons change direction and move backwards. So over one period, the electron movement has cancelled.
And now?
no!!!!What book you are reading? It looks like you have a physics book in your hands. Those misunderstandings must came out from somewhere.
Which book? Where from you are reading? optics, acoustic, mechanics, electromagnetic...
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