# 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.

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### Circuit theory basic problem

What approach do I have to take to find Vs. I don't really want an answer to this question but I want to know how to solve these circuits. I'll first tell the approach I tried. I took KVL for all the ...
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### Determining Thévenin voltage using nodal analysis

Here I want to determine $V_{th}$ without using mesh analysis and just by using nodal analysis. Now, $V_{th}$ is the same as the voltage across the $6\ \Omega$ resistor since no current passes ...
1 vote
86 views

### Voltage distribution with two batteries [closed]

I have a question regarding a simple circuit of two batteries (9V) in series with a single resistor connected to the outer contacts to prevent a short. When I'm simulating this circuit, a current also ...
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### Find Thevenin's voltage

How could I find Thevenin's voltage in this circuit? I can't use KVL since i don't know the voltage rise of the current source after removing the load.
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### Two-port network

I have been trying to solve a problem on two-port network but I am getting two different answers: APPROACH 1: In the problem the Y-Parameter is given so I converted Y parameters to H parameters and ...
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### Can an RCL circuit be asymptotically unstable? If so, what does that mean physically?

I'm analyzing the asymptotic stability of the system of ODEs that comes from an RCL circuit in series. Below is my circuit, with battery voltage $u(t)$, resistor with constant $R>0$, capacitor ...
154 views

### Voltage generation using 4 LEDs in series. Why does the voltage drop if I add a 5th LED in series?

I am making a device that doesn't use any batteries or outlet power. I need it to momentarily (<1 s) produce 5V DC or more after a bright light is applied to a hole with a 10 mm diameter. Due to ...
204 views

### Calculations of mesh and nodal analysis of my dc circuit doesnt satisfy any of the KVL or KCL conditions

So I'm working on a course project under my professor and I seem to have encountered a huge problem. I built my own circuit and solved it using mesh and nodal analysis in MATLAB, got some values but ...
29 views

1 vote
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### (KVL) Different direction results different answers

Why does clockwise direction is giving one answer and anticlockwise giving different when applying KVL? Fig E2.49 io (clockwise) = 13.33 mA and io (anticlockwise) = 0.02 A Please help me point out ...
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### I'm getting 11.547 kVA, but the answer is supposed to be 10 kVA. What am I doing wrong?

A 3-phase transformer bank consists of three identical 2300/230 V, 15 kVA single-phase transformers connected in delta/delta. The bank supplies a 20 kVA, unity p.f. 3-phase load. If one of the single-...
107 views

### How to apply KVL with current source?

In order to write an ODE for the inductor current I have to write a KVL equation that includes the current source. How do I do that?
264 views

### How to calculate unknown resistance from known current in the vector-matrix form of Ohm's law

I was trying to answer this question (pic 1) using the following method (pic 2): Step 1. Apply junction law to find the current vector. Step 2. Apply loop law to find the voltage vector and resistance ...
1 vote
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### How to apply KVL to MOSFET circuits?

I'm a little bit confused about applying KVL to circuits containing MOSFETs. I hope someone can provide some clarity. I'll be using the figure below to ask my questions. First Question If we want M1 ...
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### How to apply Nodal Analysis on this circuit?

The two voltage sources are forming a supernode right? should i take the resistance 6 ohms into consideration? How the solution will be?
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### Trouble solving a specific KVL KCL question

Now I know this is newbie-ish kinda question but I was going over the basics of KCL and KVL, and encountered this problem: For 1., I determine the drop using Ohm's law, ie. 2V for 2-4 things get ...
1 vote
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### Can anyone help me with this circuit analysis problem?

The problem I have is that my answer depends on the assumption of the direction of I1. If I assume the direction of I1 to be like in the picture, I got I1 = 0.00005A and I2 = 0.00205A. The equations I ...
1 vote
163 views

### KVL contradiction in LC circuit

Let's write down KVL in direction of current flow for an LC circuit. We have 2 cases: a) $-\frac{q}{c} + L\frac{dI}{dt} = 0$, which is wrong. b) $\frac{q}{c} + L\frac{dI}{dt} = 0$, which is the ...
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### Voltages around a loop

I am taking the voltages sum around a loop and I reached the following equation. Do you see any problem with it? vC is the voltage of the capacitor.
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### Am I applying KVL correctly to this very simple circuit?

We have this circuit: I make the following assumptions about the current: Such that $$I_1+I_2+I_3=0$$ at the blue junction. I then draw two loops, l_1 and l_2: which yields the equations -12 -...
229 views

### How to calculate current in a complex circuit? [closed]

Regarding a) How do I calculate the current for I1? Regarding b) How do I calculate IA? I have calculated I3 and I4 by using I = V/R and got the following: I3 = 5 V/10000 Ω and I4 = 5 V/100000 Ω
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### Node method circuit analysis

There is my ungraded homework. I have watched many node method videos but they didn't help me in this question. I'm struggling the determine where ground should be and choosing points A and B for ...
1 vote
329 views

### Frequency response of coupled LC oscillators

We can use coupled LC circuit to understand the normal modes of coupled oscillators of a lattice. We are using this to get the dispersion relation of the angular frequency for the oscillation. ...
1 vote
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### Analysing the behaviour of inductor in the circuit

Suppose we have an L circuit with DC power supply of emf $\mathscr{E}$ simulate this circuit – Schematic created using CircuitLab By KVL, $\mathscr{E}=L\frac{dI}{dt}$. This suggests that \\$\...
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### Current and voltage relationship for superconductors

Before superconductors enter our everyday life, we must figure out a way to relate their voltage to current. For example, how would a circuit of two superconducting lamps in series behave? What if ...
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### Is it possible to have a resistor network whose total value is unsolvable?

Home hobbyist here. I've been doing a lot of theoretical resistor, voltage divider, Ohm's law, and Kirchhoff law type problems just for practice, and ran across this older video on YouTube, which ...