C = 10^-6Analyzing Parallel RLC Circuits: A Challenging Homework Problem

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Discussion Overview

The discussion centers around a challenging homework problem involving the analysis of parallel RLC circuits, specifically focusing on resonant frequency, reactance, and quality factor (Q). Participants explore the implications of missing values for components and the appropriateness of seeking external help for homework assignments.

Discussion Character

  • Homework-related
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant expresses concern about insufficient information provided for the homework problem, questioning the ability to solve it without values for the capacitor, inductor, or reactance.
  • Another participant asks for clarification on the term "XL" and the appropriateness of seeking help online for a take-home exam.
  • A participant clarifies that collaboration and seeking help is allowed, but notes that the instructor did not explicitly encourage reaching out for assistance.
  • Inductive reactance (XL) is defined as the inductor's opposition to current, calculated using the formula XL = 2 * pi * f * L.
  • One participant suggests starting with the bandwidth equation (BW = fr/Q) to determine unknowns before moving to other equations provided.
  • There is a brief exchange about the meaning of "Rw," which is confirmed to be winding resistance.
  • A participant acknowledges a realization regarding the meaning of Rw after it is pointed out.
  • Another participant provides specific values for Q and XL, but the context of these values is not fully explored.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the sufficiency of the information provided for solving the homework problem, and there are varying opinions on the appropriateness of seeking help online.

Contextual Notes

The discussion highlights limitations in the information provided for the homework problem, including missing values for key components and the potential ambiguity in the instructor's expectations regarding collaboration and external assistance.

Keenan
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Homework Statement


CoPPLoB.jpg

2. Homework Equations
Resonant Frequency = 1 / [2 * pi * squareroot(LC)]
Inductive Reactance = 2 * pi * f *L
Capacitive Reactance = 1 / (2 * pi * f * C)
Q = XL/Rw
BW = fr/Q[/B]

The Attempt at a Solution


The information in the handy dandy jpeg I created is LITTERALLY all the information I was given for a take home exam. My instructor has never given an analysis problem that couldn't be solved, especially when there are only 2 on the exam. An electrical engineer friend and I couldn't tackle it. Without either the Capacitor, Inductor, or Reactance values I don't know that I have enough given information to solve. If I am wrong, then I lose 20% off my exam.
 
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As a non EE myself, I have two questions:
1. What does XL stand for?
2. Are you supposed to get help on the internet for your take-home exam?
 
We are allowed to collaborate, use books, the internet, seek help. My instructor never said to reach out for help. Even if this is the only time I've ever needed to reach out like this on a homework problem. Our finals are Monday of next week. I think he didn't want to spend a whole class period doing the exam.

XL stands for inductive reactance. It is the inductors opposition to current through an inductor. Inductive Reactance equals 2 x pi x frequency x inductance. It is answered in Ohms.
 
Hi Keenan. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

You start with this equation: BW = fr/Q
determine the unknown, then you move to another of those equations you supplied ...

BTW, I'm not sure what Rw stands for, but I'll pretend it stands for winding resistance
 
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RW is winding resistance.
 
I cannot believe I didn't see that ...
 
Q = 12
XL = 120
 

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