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ask_LXXXVI
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scenario 1:- as we all know in a transmission line the forward traveling wave can't be completely absorbed by a load other than Z0 (where Z0 is characteristic impedance) . So part of the wave is reflected back by the mismatched load. My doubt is when this reflected wave reaches the energy source why doesn't the source reflect part of it back again. I guess this is related to some basics which I haven't understood. If the source were to re-reflect this wave , the wave which is in forward direction would undergo some change which would depend upon the phase difference. But this doesn't happen and my doubt is why the source doesn't re-reflect the wave.
Scenario 2 :- I came across this scenario while studying the tutorials on Tx lines on IIT distance education website. Please see details of the scenario at this IIT-Bombay webpage - http://www.cdeep.iitb.ac.in/nptel/Electrical%20&%20Comm%20Engg/Transmission%20Lines%20and%20EM%20Waves/slides%202/13.4.html
[PLAIN]http://www.cdeep.iitb.ac.in/nptel/Electrical%20&%20Comm%20Engg/Transmission%20Lines%20and%20EM%20Waves/Figures/2.34.jpg
As we see the energy source is coupled somewhere along the line at a location x. The line is resonant length [tex]\lambda[/tex]/4 . The voltage source sends two waves in two different directions. As each wave sees the open circuit load it is reflected then it goes in the other direction sees the short circuit load and is again reflected. The wave keep on doing round-trips in the circuit. Now the situation is such that after each round trip phase change in the wave is 2*pi . and so the standing wave pattern keeps building up .
But my question is how is this scenario different from scenario 1 , i.e what is different in the way the source is connected here that the waves are able to do round-trips. I understand that the standing waves build up because after each round trip the phase difference is 2*pi , but my doubts are in the way the source is connected. how is that different from the scenario 1 (which happens to be the more conventional scenario)
Scenario 2 :- I came across this scenario while studying the tutorials on Tx lines on IIT distance education website. Please see details of the scenario at this IIT-Bombay webpage - http://www.cdeep.iitb.ac.in/nptel/Electrical%20&%20Comm%20Engg/Transmission%20Lines%20and%20EM%20Waves/slides%202/13.4.html
[PLAIN]http://www.cdeep.iitb.ac.in/nptel/Electrical%20&%20Comm%20Engg/Transmission%20Lines%20and%20EM%20Waves/Figures/2.34.jpg
As we see the energy source is coupled somewhere along the line at a location x. The line is resonant length [tex]\lambda[/tex]/4 . The voltage source sends two waves in two different directions. As each wave sees the open circuit load it is reflected then it goes in the other direction sees the short circuit load and is again reflected. The wave keep on doing round-trips in the circuit. Now the situation is such that after each round trip phase change in the wave is 2*pi . and so the standing wave pattern keeps building up .
But my question is how is this scenario different from scenario 1 , i.e what is different in the way the source is connected here that the waves are able to do round-trips. I understand that the standing waves build up because after each round trip the phase difference is 2*pi , but my doubts are in the way the source is connected. how is that different from the scenario 1 (which happens to be the more conventional scenario)
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