Series resistors' output voltage

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Discussion Overview

The discussion revolves around the concept of output voltage in a circuit involving series resistors, particularly in the context of voltage dividers. Participants are trying to understand a statement from an electrical engineering textbook that suggests the output voltage can no longer be defined after combining two series resistors.

Discussion Character

  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants express confusion over the textbook statement that the output voltage can no longer be defined after combining two series resistors.
  • One participant quotes the textbook directly and assumes that the output refers to the voltage across the second resistor, seeking additional insights or laws that might clarify the statement.
  • Another participant suggests that the context of the circuit, such as the presence of a battery with internal resistance and a load resistor, might explain the disappearance of the output voltage node when combining resistors.
  • Several participants emphasize the need for additional context or the exact circuit diagram to fully understand the statement.
  • One participant proposes that the statement could imply that the output voltage of a voltage divider cannot be defined after combining certain resistors, particularly in circuits involving potentiometers.

Areas of Agreement / Disagreement

Participants generally express confusion and seek clarification, indicating that there is no consensus on the interpretation of the textbook statement. Multiple competing views and interpretations remain present in the discussion.

Contextual Notes

Participants note the lack of clarity in the textbook's statement and the need for specific circuit details to resolve the confusion. The discussion highlights the importance of context in understanding electrical concepts.

Puglife
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In my electrical engineering textbook, in the section with voltage dividers, it says that after you combine two series resistors, then the output voltage can no longer be defined.

It then said that thus the equivalence was made strictly from a voltage source standpoint.

I do not understand why the output voltage would be no longer defined?

Your help much appreciated
 
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Puglife said:
In my electrical engineering textbook, in the section with voltage dividers, it says that after you combine two series resistors, then the output voltage can no longer be defined.

It then said that thus the equivalence was made strictly from a voltage source standpoint.

I do not understand why the output voltage would be no longer defined?

Your help much appreciated
The statements as you express them make no sense. Please quote it EXACTLY.
 
"after you combine two series resistors, then the output voltage can no longer be defined, thus the equivalence was made strictly from a voltage source standpoint." was a direct quote, and that's all it said. Their was a picture of a voltage source, and two series resistors right above that statement, but their was not defined output.

I am now assuming that the output is the voltage across resistor 2, because that is the only thing that makes any sense. I was just wondering if their was any like, laws, or insight that I was missing that I didnt understand
 
Puglife said:
"after you combine two series resistors, then the output voltage can no longer be defined, thus the equivalence was made strictly from a voltage source standpoint." was a direct quote, and that's all it said. Their was a picture of a voltage source, and two series resistors right above that statement, but their was not defined output.

I am now assuming that the output is the voltage across resistor 2, because that is the only thing that makes any sense. I was just wondering if their was any like, laws, or insight that I was missing that I didnt understand
Still doesn't make sense to me. I'd have to see the exact circuit to which they have applied that statement.
 
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phinds said:
Still doesn't make sense to me. I'd have to see the exact circuit to which they have applied that statement.

agree with phinds ... in particular the
after you combine two series resistors

DC circuit1.GIF


do you see any problem in this voltage divider ?
what do you think the voltage at point B is ?Dave
 
Can you scan that page of your book?

I'm wondering if the circuit comprises a battery with internal resistance and a load resistor? In that case if you combine the two resistors into one the node representing the battery terminal (aka output voltage) disappears.
 
Since the word "after" is not capitalized, does that mean it isn't the first word in the sentence...? Yes, additional context would help.
 
russ_watters said:
Yes, additional context would help.
Is essential, I think.
 
Puglife said:
after you combine two series resistors, then the output voltage can no longer be defined
I think it just means that the output voltage of a voltage divider can't be defined anymore after you combine the input resistor and the pull-down resistor in series. Like if you are solving a circuit that has a potentiometer in it or something, and need to combine the two sides of the pot to help you solve for some voltage other than the wiper voltage...
 

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