Question on voltage in Thevenins circuit

In summary: This potential is 15V. The current flowing through each resistor will cause a potential drop. The potential at the junction (V1) is the sum of the potential drops along the individual branches. So the potential at V1 is 15 + (15 + 10) = 30V.
  • #1
influx
164
2
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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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  • #2
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.
 
  • #3
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.
 
  • #4
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.
 
  • #5
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).
 

FAQ: Question on voltage in Thevenins circuit

What is a Thevenin's circuit?

A Thevenin's circuit is a simplified representation of a complex circuit that contains a voltage source, a series resistor, and an open circuit. It is used to analyze and understand the behavior of more complex circuits.

How do you calculate the Thevenin's voltage?

The Thevenin's voltage is calculated by removing all the load resistors from the circuit and measuring the voltage across the load terminals. This voltage is equal to the Thevenin's voltage.

What is the purpose of a Thevenin's circuit?

The purpose of a Thevenin's circuit is to simplify a complex circuit and make it easier to analyze and understand its behavior. It is often used in circuit analysis and design to determine the equivalent voltage and resistance of a circuit.

How do you find the Thevenin's resistance?

The Thevenin's resistance is calculated by removing all the voltage sources from the circuit and measuring the resistance between the load terminals. This resistance is equal to the Thevenin's resistance.

What are the practical applications of Thevenin's circuit?

Thevenin's circuit is used in various practical applications, such as in power systems, electronic circuits, and telecommunications. It is also used in troubleshooting and testing circuits, as well as in designing circuit networks and optimizing their performance.

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