What Steps Are Needed to Solve This Circuit Analysis Problem?

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Homework Help Overview

The discussion revolves around a circuit analysis problem involving resistors and a dependent voltage source. Participants are exploring the arrangement of resistors and the implications of the dependent source on current calculations.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the application of Kirchhoff's Voltage Law (KVL) and the arrangement of resistors, questioning whether certain components are in series or parallel. There is an exploration of how the dependent source affects the circuit analysis and current calculations.

Discussion Status

Participants are actively engaging with the problem, clarifying the circuit configuration and the role of the dependent source. Some have offered insights into the KVL equation and potential methods for calculating current, while others are questioning the assumptions made about the circuit's layout.

Contextual Notes

There is uncertainty regarding the arrangement of the resistors and the impact of the dependent voltage source on the overall circuit analysis. Participants are navigating these ambiguities as they work through the problem.

pyroknife
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Homework Statement


i attached the problem.
I am unsure how to solve this problem. I applied KVL and got 15-1I-2vx-vx-2I=0. Where I is the current in the circuit. From that equation I have 2 unknowns, so I obviously have to find I.

To find I I'd have to find Req, but I don't know how the resistors are arranged. the 2 ohm and 5ohm resistors are in series giving an equivalent R=7ohms. Is the 1ohm resistor in parallel with the combination R=7ohm?
 

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It's a series circuit -- all the components are connected in series.
 
gneill said:
It's a series circuit -- all the components are connected in series.

I don't get how it's a series circuit. Isn't the voltage dependent voltage source (2vx) separating the 1 ohm resistor from being in series with the others?
 
pyroknife said:
I don't get how it's a series circuit. Isn't the voltage dependent voltage source (2vx) separating the 1 ohm resistor from being in series with the others?

No, the dependent source is just another component in the loop. Note how there is only one path for current to follow around the single loop. This is a series circuit.

attachment.php?attachmentid=43217&stc=1&d=1327761220.gif
 

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gneill said:
No, the dependent source is just another component in the loop. Note how there is only one path for current to follow around the single loop. This is a series circuit.

attachment.php?attachmentid=43217&stc=1&d=1327761220.gif

Oh I see thanks. Does that dependent source have an effect on calculating the current? For this problem I found Req=8ohms. Would current just be 15V/8ohms=I or do I have to take into account the dependent source?
 
pyroknife said:
Oh I see thanks. Does that dependent source have an effect on calculating the current? For this problem I found Req=8ohms. Would current just be 15V/8ohms=I or do I have to take into account the dependent source?

The dependent source certainly has an effect on the current.

Start by writing the KVL equation for the loop.
 
I did and got 15-1I-2vx-vx-2I=0.
Would my other equation be V=IR, I=(15-2vx)/8
 
pyroknife said:
I did and got 15-1I-2vx-vx-2I=0.
Would my other equation be V=IR, I=(15-2vx)/8

I suppose you could use that equation, but why not something simpler, like

Vx = I*5Ω ?
 
gneill said:
I suppose you could use that equation, but why not something simpler, like

Vx = I*5Ω ?

Yeah I just realized the Circuit said what the drop was over the 5 ohm resistor
 

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