Question on voltage in Thevenins circuit

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    Circuit Voltage
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Discussion Overview

The discussion revolves around the behavior of voltage in a Thevenin circuit, specifically focusing on the voltage at node V1 and the implications of current flow (or lack thereof) in a particular section of the circuit. Participants explore concepts related to voltage, current, and resistance, aiming to clarify the relationship between these elements in the context of circuit analysis.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions what happens to the 30V voltage at node V1 and whether any voltage exists across a 10 ohm resistor, assuming no current flows in a specific part of the circuit.
  • Another participant clarifies that voltage is a potential relative to a reference point and does not "flow," emphasizing that potential changes occur only with current flow through resistance.
  • A different participant agrees that voltage does not flow and suggests that not all of the 30V will be present at node V1, prompting a request for clarification on the circuit configuration.
  • One participant reiterates that if no current flows, the potential remains unchanged, questioning whether the voltage along a specific wire is zero and providing a specific voltage value across a resistor.
  • Another participant echoes the idea that if no current is flowing, then no potential change can occur, indicating that the potential remains constant throughout the yellow branch of the circuit.

Areas of Agreement / Disagreement

Participants generally agree that voltage does not flow and that potential changes are contingent upon current flow. However, there is some uncertainty regarding the specific voltage values at different points in the circuit and the implications of the circuit configuration, indicating that the discussion remains unresolved.

Contextual Notes

Participants reference specific resistor values and configurations, but there are unresolved aspects regarding the overall circuit layout and the exact voltage measurements at various nodes.

influx
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What happens to the 30V voltage when it arrives at node V1? Does any voltage "flow" in the yellow part of the circuit? In other words what would be the voltage across the 10 ohm resistor at the top?

I know that no current flows in the yellow part of the circuit so I am assuming its the same for voltage?
 
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Voltage does not flow. Voltage is a potential with respect to some reference point. Here the reference point is the bottom rail with the ground symbol attached. So voltage does not "arrive" at some location; it's just the potential at that location.

Potential changes occur as a result of current flowing though some resistance. If no current flows, then no potential drop happens and the potential (voltage) remains unchanged.

In this problem determine where and how much current flows. Calculate the potential drops that occur for the current passing through each resistor.
 
Well, to be honest, the 30V voltage won't "arrive" at the node V1. Not all of it, anyway. Voltage doesn't flow either, but I understand what you mean.

You have three 10k ohm resistances, no 10 ohm resistances and you have two resistances at the top. Please clarify what you mean.

For your last question, use ohms law. U = R * I.

Edit: Didn't see gneill's response. You're in good hands, influx.
 
gneill said:
Voltage does not flow. Voltage is a potential with respect to some reference point. Here the reference point is the bottom rail with the ground symbol attached. So voltage does not "arrive" at some location; it's just the potential at that location.

Potential changes occur as a result of current flowing though some resistance. If no current flows, then no potential drop happens and the potential (voltage) remains unchanged.

In this problem determine where and how much current flows. Calculate the potential drops that occur for the current passing through each resistor.

I phrased that quite badly lol. What I mean is is the voltage along the yellow wire equal to 0? I know that the voltage across the first 10 ohm resistor (the one closest to the voltage source) is 15V. Same applies for the second resistor in that loop but that's as far as I have got.
 
influx said:
I phrased that quite badly lol. What I mean is is the voltage along the yellow wire equal to 0? I know that the voltage across the first 10 ohm resistor (the one closest to the voltage source) is 15V. Same applies for the second resistor in that loop but that's as far as I have got.

If no current is flowing then no potential change can occur: it remains constant. So the whole branch in yellow must remain at the same potential as where it connects (the junction you've labeled V1).
 

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