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MsHomework
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Analyzing Electric Circuits: Homework Help
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SUMMARY
The discussion focuses on solving electric circuit problems using Kirchhoff's Current Law (KCL) and Ohm's Law. The user calculates the source resistance (Rsource) as 200Ω using the formula R = V/I with a voltage source of 50V and a current of 0.25A. Participants emphasize the importance of grounding the circuit correctly to establish a reference point for voltage, which simplifies the application of KCL. The conversation highlights the necessity of writing KCL equations for nodes in the circuit to analyze current flow effectively.
PREREQUISITES- Understanding of Ohm's Law (I=V/R)
- Familiarity with Kirchhoff's Current Law (KCL)
- Basic circuit analysis techniques
- Knowledge of series and parallel resistor combinations
- Learn how to apply Kirchhoff's Current Law in complex circuits
- Study techniques for simplifying circuit analysis using node voltage methods
- Explore the implications of grounding in circuit design
- Review examples of series and parallel resistor calculations
Students studying electrical engineering, educators teaching circuit analysis, and anyone seeking to improve their understanding of electric circuits and KCL applications.
- #2
MsHomework
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Anyone... Please help! I have tried so many times to figure this out but I can't! A hint my teacher gave me is to figure out the R4
- #3
berkeman
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MsHomework said:
Ground the bottom of the voltage source and write the KCL at the node between the left resistor and the right parallel resistors. What does that equation do for you?
- #4
MsHomework
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How do I ground it! I did not learn that...
- #5
berkeman
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MsHomework said:
It just means draw a little ground symbol on that bottom wire, to indicate that you are considering it to be the zero volts potential for the circuit. That way your voltage source output is the value of the source (since it is referenced to zero volts). You could arbitrarily set the bottom of the voltage source to something else like "10 volts", but that just introduces extra complexity into the KCL.
- #6
MsHomework
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64. (a) R4 5 2.50 x 102
I1 = 0.250 A
I2 = 0.150 A
I4 = 0.100 A
(b) V2 = 16.7 V
V3 = 8.30 V
This is the answer from the back of the textbook... Also my teacher said to use the basics aka... I am not suppose to ground!
I1 = 0.250 A
I2 = 0.150 A
I4 = 0.100 A
(b) V2 = 16.7 V
V3 = 8.30 V
This is the answer from the back of the textbook... Also my teacher said to use the basics aka... I am not suppose to ground!
- #7
berkeman
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MsHomework said:
Okay, no problemo. Nothing fancy.
Just label that bottom wire with "0 volts", and write the one KCL equation for the top middle node. Simple!
- #8
MsHomework
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Can you show me step by step, because I still am confused!
- #9
berkeman
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MsHomework said:
No, sorry, that's now how we handle Homework Help at the PF (which you know).
Tell us how to write KCL (Kirchoff's Current Law) equations. Then write the KCL for the node in the middle of the upper branch as I mentioned several times already.
http://www.wiziq.com/tutorial/32583-Solving-problems-using-Kirchoff-s-Law-I
.
- #10
MsHomework
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Just a quick question, How come you have to put 0 volts at the bottom in the parallel...
- #11
berkeman
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MsHomework said:
With the KCL, you will write the sum of all currents leaving that central node = 0 (amps or milliamps). When you write the currents as V/R for each branch, the delta-V is the voltage at the node minus the voltage at the node on the other side of the resistance. If you label the bottom wire as 0 volts, then that second voltage in the subtraction goes away in the equation (because it is 0). It's mostly a convenience thing for writing the KCL equations -- pick a logical node to label as 0 volts before starting to write out the KCL equation(s).
If a node is already labeled with a ground symbol in a schematic, you automatically take that node as being at 0 volts.
Can you take a cut at writing the KCL at that node now?
- #12
MsHomework
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I am sorry, but I personally feel more confused! I don`t feel that you are helping me as much. Thank you for trying to help!
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