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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Electric circuit Characteristic equation from drawing [closed]

Is there a tool that I can draw an electric circuit and it gives me its characteristic equation? Not have to solve it, just give me the equation?
Dor Gotleyb's user avatar
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How to formulate an equation for the electrical circuit with both a voltage and a current source?

This problem asks me to find Rx, the electrical power of each element and the algebraic sum of the electrical powers of all elements. How to apply Kirchhoff's and Ohm's law correctly in this problem? ...
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How to calculate current limiter resistor when voltage regulator is involved?

I'm designing my first PCB and I'm not sure if the diagram I found on a datasheet is complete. For what I have read, there should be a resistor between R1 and the transistor Tr1. I have followed this ...
Waripolazo's user avatar
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How to calculate the value of resistor R2?

How to find the value of R2 in this circuit? If I1 is 8 mA in this case (I = I1 + I2) and then given 5 V over R2 and R3, 5 V/0.008 A = 625 Ω. Is this answer valid ? Or is it 5 V/I = 2mA = 2.5 = 1/2.5 +...
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What are the currents and the power dissipated by the load \$R_{T}\$ in the following circuit

The circuit has 2 voltage sources one of which is 0.5UR2, one current source, resistor elements R1 & R2, the load is RT 10 ohms. Having the following circuit, I have used the Kirchhoff's circuit ...
Chum Chum's user avatar
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Energy stored in a magnetically coupled circuit

In the circuit shown, inductors $$L_1,L_2$$ are magnetically coupled with the mutual inductance being $$M$$. The red dots are for dot convention. Normally,the energy stored in such a circuit is $$\...
green_blue's user avatar
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Looking for intuition for KVL regarding parallel resistors

I'm completely new to electrical engineering. I came across KVL and my previous intuition about how voltage works broke down when coming across an example of KVL and parallel resistors. Some ...
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DC circuit and capacitor

What method should I use to calculate the voltage across C1 and C2 in the following circuit in DC conditions? I've already tried using KCL, but I'm confused with what point on the circuit to use. Is ...
Agatha Hadasa's user avatar
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How to perform Kirchhoff's Voltage Law on an open circuit? [closed]

I am wondering how to perform KVL on an open circuit. For V_s = 10V, I have determined the V across R2 to be 10 Ohms but am confused about R3. The algebraic sum of the voltages around any closed loop ...
9_daytona's user avatar
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Confused about usage of Ohm's law & Kirchhoff's laws to solve a circuit

I'm solving this circuit using Ohm's law and Kirchhoff's laws: I solved the circuit correctly the second time. Equation A: $$I_1-I_0-6=0$$ Equation B: $$-120\ \mathrm{V}+I_0\cdot 10+I_1\cdot 50 = 0$$ ...
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Is it correct to generalize Kirchoff's current law to areas?

I'm very new at learning electronics, and I came across KCL. I think I understand it, I've used it to solve problems, and it makes sense to me (it feels very much like conservation laws in mechanics, ...
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KVL on circuit with transistor

I have a question regarding applying KVL in a circuit with a npn-transistor. Unfortunately this is badly documented in the textbook, and I couldn't find the answer so far. For the circuit below, it ...
LLScheme's user avatar
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Why does this op-amp circuit show current flowing like that?

This image shows an op-amp being powered. Is there any reason why it shows current flowing from the negative side of the bottom battery into the op-amp or why it shows current flowing from the ...
Analysis101's user avatar
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Doubt in applying KVL

I want to apply KVL to loops abcda and befcb in the circuit given below. Is there any role of the 2A current source in those two loops, that I need to consider before applying KVL?
Sagar K. Biswal's user avatar
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How can there be no Thévenin voltage with only a dependent voltage source? [closed]

I don't understand why the Thévenin equivalent is equal to zero in this case because, if the load is a resistance, then yes, the circuit would be dead as there would be no voltage drop across Vx. But ...
Analysis101's user avatar
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Example 3.17: find Vo in a circuit containing a voltage controlled voltage source

Trying to solve this circuit using mesh analysis. However, I am having trouble understanding why Vx = 4kI1 specifically why to go through the 4k resistor using current I1, my intuition wants to set Vx ...
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Including resistance between supernodes

Here,as per the circuit,we can take \$V_1\$ and \$V_3\$ with the voltage source across them as a supernode(as the area marked in red). In the red marked portion i.e supernode,we see that current can ...
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Find Vs and the power supplied by the 10V source [duplicate]

I am stuck on this textbook problem where the chapter is about Kirchhoff's Laws (Ohms, KCL, KVL, Voltage Division, Current Division, Wye-Delta, and lastly Dependent Sources). The chapter does not ...
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A student who should know how to do this, kirchhoff's edition [closed]

We know that the voltage of the volt meter gives 2V and the ammeter is 2A. We must find I1 and I2, and I'm at a loss as to what the voltage can be used for. Especially considering the correction of ...
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Special case nodal analysis

I tried to calculate, but I'm quite confused to go further. The calculations can be seen in the image itself. This is a special case, nodal analysis with special dependent voltage source branch. How ...
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Special case of nodal analysis

In this diagram, we see node V2, I can understand how it can be treated as a node. But I don't understand in the equation how \$-v2(0)\$ comes. I thought maybe the R for short circuit is 0, then also ...
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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 ...
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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 ...
olympus_mons's user avatar
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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.
Serkratos121's user avatar
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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 ...
travelingbones's user avatar
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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 ...
manubrio's user avatar
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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 ...
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Amplifier circuit: Voltage divider x KCL

I was checking the solution to one question when I found out I couldn't use voltage divider rule to easy the formulas, the amplofier circuit (infinite gain): My first attempt: $$ V_{x}=\frac{R_4}{R_1+...
Duca's user avatar
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How do you use nodal analysis to this circuit?

By using mesh analysis I have 4 equations: 6ia - 2ib = 24 -2ia + 12ib -20ic - 2id = 0 -8ib + 12ic = 0 -2ib + 12ic + 3id = 0 Got ic = 8/3 A, so Vo = 4(8/3) = 32/3 V ; correct me if I'm wrong But I don'...
New student's user avatar
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2 answers
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Simplifying a circuit for nodal analysis [closed]

I am trying to simplify/classify the following circuit: My textbook says it is a four-node circuit but I am coming up with 3 nodes. Doesn't the "Ref." dot and the rightmost dot combine into ...
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Circuit reduction: Voltage across terminals [closed]

I'm new to electrical engineering and there is debate in my class about a problem. We are asked to find the voltage across A and B after reducing the circuit. Circuit is symmetrical. Information given:...
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How to determine the directions of voltages across resistors in circuit diagrams?

In the following diagram, the directions of both currents and voltages for voltage sources are shown. My task is to write KCL and KVL for all 3 loops, and my question concerns KVL. I believe I am ...
Nare Avetisyan's user avatar
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5 answers
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Does current prefer to take a series path over a parallel path?

simulate this circuit – Schematic created using CircuitLab Based on the simulation I have done, current here prefers to take the C1 - R2 path first and once C1 is saturated and cuts off it then ...
Dan's user avatar
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Is there a sequence of thought I can do to solve complex circuits using only KVL and KCL?

This question took me a good 20-30mins of solving, and this just feels like a long time especially when I take my midterm exam it will only be 2 circuits in 1 hour only, so I need to make sure I find ...
Ahmed Soliman's user avatar
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How does the current direction affect KVL?

I'm a bit confused about using KVL on circuits. For example, suppose I have this circuit, and we are given the direction of inductors current and capacitors current, and we have to find VA. Using the ...
Rose Haze's user avatar
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Current constant circuit

Did this circuit ok since no resistor on circuit? the voltage for each led is 3V for each led. Did i need to add resistor since 3Vx7=21V. The diode is led driver for 15mA. Btw, I'm designed for ...
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KCL confusion about currents direction

Sometimes when I use KCL for nodes in a circuit I cannot correctly determine the direction of the currents. My book also says that according to KCL the algebraic sum of currents entering a node is ...
math_noob's user avatar
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KVL/KCL and Thevenin Concept [closed]

I have solved the following question but little bit confused that this solution is correct or not as attached in figure. How can I solve this question by KCL/KVL also if by using Thevinin theorem its ...
Zerox's user avatar
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Applying KVL to a grounded MOSFET circuit

I'm rather confused as to how to how this circuit doesn't violate KVL: The two node voltages on the right side of the loop add to -4.16V, which means the voltages on the left should add to 4.16V, ...
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Derive a State-Space Model for an Electric Circuit with three Energy Storage Components

I want to model the shown circuit diagram with a state-space model. However, I cant solve it since I obtain four unknown variables while only three of the derived equations are linear independent. ...
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Why is my expression for current I(2) wrong?

simulate this circuit – Schematic created using CircuitLab Hi! My question is if I(2) is a current that runs from Node 1 to Node 2 then the expression of I(2) as a function of I(A), I(B), R1, R2 ...
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What is I1, I2, I3 and I4?

simulate this circuit – Schematic created using CircuitLab I have really gotten stuck on this question where I need to calculate I1, I2, I3 and I4. The numbers for the circuit is: V(a)=2 V, V(b)=...
DiodeLight97's user avatar
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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 ...
blablubbb's user avatar
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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 ...
Math Keeps Me Busy's user avatar
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Why does the E-Field not change given two parallel capacitors?

I just cannot imagine, why connecting two voltage sources in parallel does not change the E-Field (strenghting it) and thus does not lead to higher voltage. In this case charged plate capacitors are ...
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KCL in a particular node (problem)

Above is an AC circuit in which terminals A and B are used to connect to a load. I am asked to find the equations for currents coming into and out of nodes 1 and 2 (using KCL). I had no trouble ...
kauselis3000's user avatar
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1 answer
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Why is clockwise KVL done like this?

My task is to find voltage across the resistor of this circuit where all the 4 components are connected in series with each other. The given information are : V1 (t) = 100 * sin(100 * t) V, R = 100 ...
RK Eshat's user avatar
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Mesh loop analysis 2 loops, 2 voltage sources of different polarity

I'm having problems trying to work the following problem. The polarity is reversed on the right hand loop so I guess it becomes a -7v however does the current now go clockwise in loop one and anti in ...
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