Can anyone help me out in teaching this..!

[santom]

Can anyone please guide me as how to go about it..

Santom

 

[kspalla]

I guess the answer is 3.
The reasons are
1) At DC, the level is high this means that the circuit is open.
2) The frequency separation is 5MHz which is lambda /2. so lambda is 10MHz.

 

[mauloftin]

I guess the answer is 3.
The reasons are
1) At DC, the level is high this means that the circuit is open.
2) The frequency separation is 5MHz which is lambda /2. so lambda is 10MHz.

hmmm, so
1) it is true

and 2) hmmm... it si true too

I think so

 

[santom]

The correct answer is option 1.
Can anyone explain me that?

 

[mauloftin]

The correct answer is option 1.
Can anyone explain me that?

oou,

I think, that 1 is not correct, because Short and DC is minimum level, there is maximum..... or not ?? hmm...

 

[radiohead]

I agree with kspalla, the answer is 3

 

[VSWR]

Who is telling you statement 1 is correct? Correct answer is statement 3.

The correct answer is option 1.
Can anyone explain me that?

 

[biff44]

kspalla's logic is impecable.

 

[mauloftin]

So may be, my idea, why is it correct 1:

What is UT ? I think, there is problem.... point "a" is not end, so and is UT......... eee, it is stupid because if is "a" short, is "a" end point.....

NO NO, i think that correct is 3 ! 1 is stupidity

If "a" is short and DC (f=0),can not be level on output !

 

[sreevyas]

Answer is 3,
kspalla explained logic

 

[santom]

I am sorry .I am not able to understand that.Can anyone explain me in some more in a detailed way please...

 

[biff44]

Lets expand on what Kspalla said.

This is a plot of output voltage. Answers 1 or 2 involve putting a short circuited stub across the transmission line. At zero frequency a short circuit stub is...a short circuit! You can check this with an ohmeter if you do not believe it! So if you had put a short circuit across the transmission line, the voltage output when you were at 0 hz would have to be zero. From the graph, this is not the case. At zero hertz, the voltage output is a maximum. So answers 1 or 2 can not be right.

That leaves answers 3 or 4. Which one is right?

Lets look at 10 MHz. If the stub were open circuited, and half wavelength at 10 MHz, then an open circuit transforms to an open circuit, and puting that stub across the 50 ohm line would give you a voltage maximum. So 4 might be right. If the stub were open circuited, and a full wavelength long at 10 MHz, then an open circuit still transforms to an open circuit (2 times around the smith chart). So 3 is still a possibility too.

We still do not know if it is 3 or 4.

Lets look now at 2.5 MHz. A full wavelength line (3) at 10 MHz is really just a quarterwave long line at 2.5 MHz. A quarter wave line will transform an open circuit to a short circuit. And the graph shows that the Vout is a minimum at 2.5 MHz. This is consistent with a open circuited quarterwave long line at 2.5 MHz, which would also be an open circuited full wavelength line at 10 MHz.

So it looks like 3 is the correct answer.

Rich

www.maguffinmicrowave.com

 

[santom]

Thanks to all of you..It was very helpful and informative

 

[mauloftin]

...
We still do not know if it is 3 or 4.

Lets look now at 2.5 MHz. A full wavelength line (3) at 10 MHz is really just a quarterwave long line at 2.5 MHz. A quarter wave line will transform an open circuit to a short circuit. And the graph shows that the Vout is a minimum at 2.5 MHz. This is consistent with a open circuited quarterwave long line at 2.5 MHz, which would also be an open circuited full wavelength line at 10 MHz.

So it looks like 3 is the correct answer.

Rich

www.maguffinmicrowave.com

May be easier: it is snading wave, and period is lambda/2, so there is peroide 5 MHz, so lambda "=" 10 MHz. (change frequency = the same, as change the length open stub)

I think, that this is correct idea too, or not ?

 

[kspalla]

yes you are

 

[DDavid]

Hi

Guys it maybe correct 1
Who says that signal that in the figure is voltage!??!
Maybe it's current than in DC we will have max
In figure y axis define as Level without units!

It's only my thought
David

 

[mauloftin]

Hi

Guys it maybe correct 1
Who says that signal that in the figure is voltage!??!
Maybe it's current than in DC we will have max
In figure y axis define as Level without units!

It's only my thought
David

I think, that there is:"The diagram shows the output signal....." - so output signal usually not only current - may be, my idea