# Questions tagged [kirchhoffs-laws]

Kirchhoff's circuit laws deal with the conservation of charge and energy in a circuit.

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### Finding a current in a given circuit

The problem has given the following circuit: And asked to find the value(s) of Ix if the elements absorb the power(s) given. I tired to set up KCL/KVL but I keep getting stuck. I first drew this: ...
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### Cascading/multiple voltage dividers

Could someone explain the voltage readings on the following "oscilloscopes" of the simulated schematics below: (I understand the concept of a voltage divider but it seems something less ...
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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 ...
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### Potentiometer Working

Let's suppose that $E \gt V$. Now, the voltage $V_b$ at point $b$ will always be $V$ and will not depend on $E$. Similarly the voltage $V_A$ at point $A$ is $V_E$ which will be ...
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### nodal analysis, current direction

Right, first the diagram, I tried using the schematic function,but it never actually added the schematic. I picked this because it illustrates my confusion in the simplest schematic I could find. We'...
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### Finding the output of a node with two diodes (kind of full-wave rectifier)

Maybe this question sound stupid, but I really suck at electronics. I have this circuit here: simulate this circuit – Schematic created using CircuitLab and i want to find the values of ...
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### Performing small signal ac analysis with non-linear components

I have written a circuit simulator that uses Kirchoff's voltage and current laws to solve linear circuits containing capacitors, resistors, inductors and op-amps (where the op-amps are assumed to be ...
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### How can I find the voltage across R4?

I am trying to find the voltage across R4 in the following circuit: It confuses me that there are 2 voltage sources. I am not sure how to approach it, so I tried this: First, I use Kirchoff's ...
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### Kirchhoff Voltage Law in a two port network

In a tutorial about h parameters of a two port network, I find the below snippet in the image unable to grasp. According to KVL, the total voltage in a loop is the algebraic sum of the individual ...
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### Ideal Battery in Circuit

Does Kirchoff's voltage law hold when we connect a single battery to a circuit that has no other components. If it does hold, kindly let me know how. If it doesn't, how do we reconcile with that?
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### Resistor Coefficient Voltage Matrix Doesn't have a Solution

Follow the link to the circuit that I need to solve for all the resistor voltage drops. I have to make 5 linearly independent equations in order to solve for all 5 unknown voltages. Using the loops ...
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### Resources on Noise Circuits

Back when I was taking an RFIC design course, I was pretty disappointed by the noise part of the class, specifically calculating the output-referred noise voltage, noise figure of an amplifier, etc. ...
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### 3 Loop Circuit-Kirchhoff's Voltage Law(KVL)

I am struggling to solve the circuit given in the attachment. I have found the current values in the circuit and I am not sure about it(I do not have the answer sheet). I would like to ask whether it ...
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### Should I perform Delta to Y before analysing the following circuit?

I am working on the following circuit: I am asked to find the node voltages at N1, N2 and N3. This problem seems pretty straight forward to me but the challenge I'm facing is due to resistor R4. ...
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### How to solve for node voltages using mesh analysis?

I am given the following circuit to analyze: The problem asks me to solve for the unknown currents and then find the node voltages at N1 and N2. Here are the mesh equations I came up with: $$Mesh1$$ \$...
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### Output Voltage Formula verification of Operational Amplifier circuit

I'm trying to built an op-amp circuit for a PT100 temperature sensor. I've found the following circuit diagram online (from a polish website): And I'm trying to find the formula for the output ...
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### How to write inductor ODE equation properly?

I've drawn a following scheme, and now want to write ODE system for describing inner processes, in order to explore it: simulate this circuit – Schematic created using CircuitLab I wrote the ...
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### Finding current through a diode

I am asked to find the current through the second diode, as shown in the image below. I have gone through my procedure to find this current, and can not figure out why my answer is wrong. What I did ...
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### Y-Δ transform with generators. Equivalence of three-terminal devices

So my book asks me to find $i_a, i_b, i_c$ (as functions of $v_1, v_2, v_3$) as well as $G_a, G_b, G_c$ such that the circuit on the right picture (shown below) is equivalent to the circuit on ...
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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 ...
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### What is the best approach to calculate the transfer function of this RC circuit?

I want to calculate the transfer function of the circuit below. I tried to calculate the equivalent impedance of each block and work my way with voltage dividers until I get to V3, but this method is ...
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### Kirchoff law exercise

I need to determine the current across the 4 ohm resistor (name it I1). What I calculated, thought out so far : Current of 2 ohm resistor : I=5V/2ohm=2,5A. I Think this current is flow towards the A ...
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### How can I solve for impedances if given RMS currents?

Given a very simple circuit such as this. If I where given the RMS values for the three currents, how could I go about solving R and Xl? (the resistor and inductor in paralell) I know I can not ...
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### Calculate the Norton Resistance and Current and the Thevenin Voltage of the following circuit

U=10 V, R=10 ohm I calculated the resistance as such: 1/Rt = 1/R + 1/R <=> Rt = R/2 = 5 ohm To calculate the voltage I did KVL as such: U - 2Ur = 0 <=> Ur = 5V, where Ur is the voltage in the ...
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### Calculating the Thevenin Voltage of this circuit

What I did was apply kirchoff's voltage law to the closed network with the 2 resistors and the voltage source to calculate the voltage of the resistors. I got U - 2*Uresistor =0 <=> Uresistor =5V ...