My instructor said use thevenin theorem to get the RL voltage , and he said it would be simplier to get the other voltage after you get the voltage at RL ,,, and i dont know what method i use after i get the ,RL voltage is 3.24324V .. RTH=60/11 ,,, ETH=5.454545 V
i need to findd the resistor voltage across the circuits help

Hello again,

Since he said "it would be simpler to get the other voltage(s) after you get the voltage at RL" then it sounds like he just wants you to use your imagination to try to find another way to find the other voltages. You can do that by simply working backwards noting the current through the previous section. Note that to start, you already know the voltage at the output so that means you know the current through the output, and since that same current flows through that 4 ohm resistor also (it's in series) that means you know the voltage across that 4 ohm resistor.

Referring to the image in the attachement with all the parts labeled...

Once you have the voltage at v6 and the current through RL, that means you know the current through R5, and once you know that, you know the voltage at v4. Now that you know the voltage at v4, you can calculate the current through R4, and knowing the current through R4 and R5 you can calculate the voltage at v2 because you know the voltage across R3 due to the current through R3 being the sum of the other two currents. That gives you all the voltages except v1, and you can calculate that by simply adding up the voltages of all three voltage sources.

So you see once you have the output voltage it gets easier so you dont really have to use Thev/Norton for each and every single resistor. You do have to know that the sum of the currents entering a node is equal to zero though, and then work backwards trying to find any current necessary in order to reveal the voltage across the next resistor to the left, and then that gives you the next voltage to the left, and then repeat the process again working right to left.

 

Since he said "it would be simpler to get the other voltage(s) after you get the voltage at RL" then it sounds like he just wants you to use your imagination to try to find another way to find the other voltages.

Maybe the instructor meant that it would be simpler to find the next Thevenin equivalents after finding the first one.

The problem statement the TS gave said "Using Thevenin theorem, calculate Eth, Rth, and get all the voltage in every single resistor in the circuit."

Now put the first phrase at the end and get "Calculate Eth, Rth, and get all the voltage in every single resistor in the circuit using Thevenin theorem." This slight rearrangement would seem to clarify the notion that what is wanted is to calculate the Thevenin equivalent which drives each resistor. The question is whether the phrase "Using Thevenin theorem" modifies only "...calculate Eth, Rth...", or does it also modify "get all the voltage in every single resistor in the circuit."

I asked the TS this specific question and I'm not sure his answer was responsive. We have some language barrier here. Maybe the instructor wants the TS to get a lot of practice calculating Thevenin equivalents.

What if the problem statement had been "Calculate Eth, Rth using Thevenin theorem, and get all the voltage in every single resistor in the circuit."

I asked the TS to post a picture of the problem as it appears in his text. Maybe this problem isn't from a text; maybe what the TS posted is from a handout. At any rate, it's not perfectly clear what the problem wants.

It seems that the TS may not know nodal and mesh analysis, but he does know how to use superposition.

 

Maybe the instructor meant that it would be simpler to find the next Thevenin equivalents after finding the first one.

The problem statement the TS gave said "Using Thevenin theorem, calculate Eth, Rth, and get all the voltage in every single resistor in the circuit."

Now put the first phrase at the end and get "Calculate Eth, Rth, and get all the voltage in every single resistor in the circuit using Thevenin theorem." This slight rearrangement would seem to clarify the notion that what is wanted is to calculate the Thevenin equivalent which drives each resistor. The question is whether the phrase "Using Thevenin theorem" modifies only "...calculate Eth, Rth...", or does it also modify "get all the voltage in every single resistor in the circuit."

I asked the TS this specific question and I'm not sure his answer was responsive. We have some language barrier here. Maybe the instructor wants the TS to get a lot of practice calculating Thevenin equivalents.

What if the problem statement had been "Calculate Eth, Rth using Thevenin theorem, and get all the voltage in every single resistor in the circuit."

I asked the TS to post a picture of the problem as it appears in his text. Maybe this problem isn't from a text; maybe what the TS posted is from a handout. At any rate, it's not perfectly clear what the problem wants.

It seems that the TS may not know nodal and mesh analysis, but he does know how to use superposition.

Hi again,

Yes i had similar thoughts, and due to the lack of information i just decided to post some solution techniques and see where it leads us. He's just going to have to be more clear on how this is to be done. I think only he can state that because he would know how the class has been conducted so far as to what they were doing previously and that would tell us what the class had been using up to this point. I guess they didnt use Nodal yet, unless he just forgot how to do it. Too many possibilities to guess here so we'll just have to wait and see if he can clarify. Did he even say he knew how to use superposition? I dont remember reading that but who knows.

 

I also thought maybe the instructor stated their desires perfectly. Starting at V1 and R1, create the Thevenin equivalent and work your way to the load. So I followed that instruction to the end.

 

Good idea; I like it. It's a systematic way to calculate a new Thevenin equivalent for each resistor, but the TS said in post #31: "My instructor said use thevenin theorem to get the RL voltage , and he said it would be simplier to get the other voltage after you get the voltage at RL"

I wonder if the TS has bailed?

 

Good idea; I like it. It's a systematic way to calculate a new Thevenin equivalent for each resistor, but the TS said in post #31: "My instructor said use thevenin theorem to get the RL voltage , and he said it would be simplier to get the other voltage after you get the voltage at RL"

I wonder if the TS has bailed?

I know that's what the TS said the instructor said. The TS also said he didn't know about nodal analysis. Absent a decent reference to his curriculum we try out best to decipher the assignment. I find the word "circuits" interesting in the problem statement as there was only one circuit drawn. The only other circuits were the one's created with each Thevenin equivalent.

Hopefully the TS did not bail.

 

While it is unfortunate that we are having to guess (again) at what the problem statement really was, at least by differently people guessing different things the TS (and others in the future) are getting to see several different ways of approaching the same problem.

 

@WBahn I guess there is a silver lining in the homework cloud.

 

GUYS THANK YOU ALL I GOT PERFECT .. THANK YOU SO MUCH .. FOR GIVING ME IDEA SPECIALLY TO ELECT AND MR ... THANK YOU .... THEVENIN IS NICE TO LEARN .. CHALLENGING THANK YOU ALL HAHAHAHAHAHAHA <3 <3 <3 GO ECE

 

I have undeleted all posts and given a new title (as that was also deleted).
This is done to keep the thread for reference and help for others.

Bertus