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Questions tagged [kirchhoffs-laws]

Kirchhoff's circuit laws are important for circuit analysis. There are two laws: Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL). KCL states that the sum of currents flowing into a node is zero, and KVL states that the directed sum of voltages around a closed loop is zero. Consider also using the "circuit-analysis" with this tag.

Kirchhoff's circuit laws are important for circuit analysis. There are two laws: Kirchhoff's Current Law (KCL) and Kirchhoff's Voltage Law (KVL). KCL states that the sum of currents flowing into a node is zero: $$\sum_{k=1}^n I_k = 0$$

KVL states that the directed sum of voltages around a closed loop is zero: $$\sum_{k=1}^n V_k = 0$$

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How does the current know how much to flow, before having seen the resistor?

With the following circuits as examples : and How will the current I know how much to flow? Would any other wave travel first in the circuit and then come back and say so much current should flow?
Prabhanjan Naib
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How did scientists deal with electronics' problems before Kirchhoff and Ohm's laws?

Both physicists developed really powerful laws which still nowadays rule the electronic behavior of circuits. These help us every day to solve problems, calculate circuit variables… but how did engineers do it before the said laws were…
xvlaze
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What is wrong about this application of Kirchhoffs Current Law?

At a recent exam I had this very simple problem concerning Kirchhoffs Laws: I am concerned with problem c Now my understanding of this is: I can combine both nodes, and since all currents in the node need to cancel out, \$i_c\$ should be 2A. Now my…
peacememories
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Does this experiment show that Kirchhoff's Law hold when there's a changing magnetic field involved in a circuit?

In this video, the electrical engineer and youtuber Mehdi Sadaghdar (ElectroBOOM) disagrees with another video from professor Walter Lewin. Basically, professor Lewin shows in an experiment that if we have two different resistances connected in a…
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Basics of Transistors

something has been bothering me for awhile. When I look at a circuit involving anything more complicated than RLC components (and perhaps op-amps) I struggle to figure out what it's doing unless its a configuration I've seen before. In contrast, I…
NickHalden
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Circuit yields a peculiar contradiction between KCL, KVL and Faraday's law

I don't know if this particular circuit/loop is covered in another question but I stumbled upon a video where a peculiar consequence occurs for the following circuit: For the above circuit loop according to Faraday's law of induction one can…
user16307
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How do I decide whether to use Kirchhoff's Voltage Law or Kirchhoff's Current Law?

When I solve questions, I usually get confused between when to use the Kirchhoff's Voltage Law (KVL) and when Kirchhoff's Current Law (KCL). Please help.
user1799
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Do all components obey Kirchhoff's Current Law?

Kirchhoff's Current Law states that the net current through a node is always 0. AFAIK this derives from conservation of charge principle. My question is, is KCL applicable to any electrical component? For example is it applicable to transistors,…
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Explain kirchoff's law in Plain English

I'm having trouble in explaining kirchoff's laws to my cousin who is studying in first year Engineering. Can somebody explain me in simple plain english. Thank you very much in advance :)
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Can two voltmeters connected to the same terminals show different values? Circuit with induced EMF

The circuit shown below consists of two resistors connected in series that form a closed loop. No electrical sources are in that loop.Let’s assume that the resistance of the wires that connect the resistors and form the loop is zero.Inside the loop…
Slaven Tojić
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Trouble understanding when voltages get split

I am having trouble solving this Op-Amp problem. I'm looking for Vo, and am confused as what to do with the 9V supply and the 2k and 6k resistors. Would the 9V be split between these two resistors? Also, when doing KCL for the V- value, should I…
lm1998
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Solving an ideal opamp-circuit leads to a contradiction

Well, I am trying to analyze the following circuit: simulate this circuit – Schematic created using CircuitLab When I use and apply KCL, I can write the following set of…
Jan Eerland
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How does a dead battery look in a circuit?

I'm working on a Kirchhoff's problem where two car batteries are connected in parallel. One is dead and one is good. It's a basic three variable problem where I'm working out the three different currents (I1/I2/I3) in the circuit when the switch…
Chef Flambe
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Kirchhoff's Laws and Circuits?

I just started circuit analysis today and learn't about Kirchhoff's Laws. Its pretty straightforward, but in all the examples my book gives they already specify the direction of the current and the end of the branch with the higher voltage. For…
dfg
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How many measurements are needed to determine a black box with four terminals?

I am having a black box with four terminals and just resistors inside. I can model it like this: simulate this circuit – Schematic created using CircuitLab If I have four different currents and four different potentials at the four different…
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