Questions tagged [circuit-theory]
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Does KVL guarantee identical voltages/currents in similar circuits?
I have a question that is a bit abstract. Assuming I have two proper linear circuits, A and B, which have:
The same ideal components (for example, voltage source, inductor, capacitor, resistor)
The ...
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Power dissipation in an IC
Here is LM741 op amp circuit in Figure 1. The amplifier has two power supplies \$V_{cc}\$ and -\$V_{ee}\$. The up arrows are connected to the positive power supply \$V_{cc}\$ which is +15 V. Current ...
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Transient circuit analysis with additional source
The circuit in the image below is what I get when I open the switch of a larger circuit which I have already analysed. Therefore, I know the initial condition.
simulate this circuit – Schematic ...
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Are voltage ratings defined differently for capacitors and light bulbs?
The voltage rating of a capacitor is the maximum operating voltage, while the voltage rating of a light bulb is its normal operating voltage. Are there two different definitions of voltage ratings, or ...
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How can I infer a circuit topology only from measuring/controlling its input and output?
Let's have a circuit only composed of resistors connected in a given topology. This topology (network) has a well defined boundary (input/output connectors) but otherwise we don't know how it is ...
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IV curve arithmetic - reference request
When playing around with electrical concepts in my head, I realized that the IV characteristic of any combination of elements, in series or in parallel, can be computed by simply adding the IV curves ...
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How to write the equation for the input side of a JFET?
I have been reading about the voltage gain of JFET, but I am unable to understand how to write the equation for the input side. Can somebody explain the method to write the equation for the input ...
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Resistive network with two voltage sources
Update: (I updated the description/Question for clarity)
I am currently stuck trying to solve a seemingly simple resistive network. The voltages U1 and U2, aswell as Rr are known. The unknown ...
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Why doesn't mesh analysis work here?
I am new to theory of circuits and I just learned about mesh analysis. When I was doing some reviewing, I stumbled across this question and wonder if you can use it here:
I plugged the equation into ...
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Transient Charge Density in Conductor
Veritasium's (Derek Muller's) video How Electricity Actually Works makes the claim at
4:44 that:
The truth is, if you average over a few atoms, you find the charge density everywhere inside a ...
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Computing input resistance of two common-base configurations
When computing the input resistance of this common base configuration, the collector current \$I_C\$ is approximated as equal to the emitter current \$I_E\$:
simulate this circuit – Schematic ...
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Combining cable resistance and law of resistances in parallel circuits
For a parallel circuit it is true that
\$1/R = 1/R_{1} + 1/R_{2}\$
Consider two equal cable switched parallel to each other. Their individual resistance is \$R = phi * l * A\$, where phi is constant.
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Does a resistor between two pairs of series resistors affect the equivalent resistance?
For the below DC circuit, does the 1Ω resistor in the middle have an effect on the equivalent resistance?
If it does, how would you calculate the equivalent resistance? The rules for series and ...
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How to find a missing resistor?
This seems to be a really simple question. I'm not really sure where I went wrong in my solution. Please forgive me if this seems irritatingly simple, I've only just started learning about electric ...
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How to simplify this complex DC circuit?
I find it very hard to simplify this circuit. Currently practicing for my removal exam and this was one of the problems I failed on one of my previous exams.
Especially the middle part makes me so ...