# What is Kirchoff's voltage law: Definition and 30 Discussions

Kirchhoff's circuit laws are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits. They were first described in 1845 by German physicist Gustav Kirchhoff. This generalized the work of Georg Ohm and preceded the work of James Clerk Maxwell. Widely used in electrical engineering, they are also called Kirchhoff's rules or simply Kirchhoff's laws. These laws can be applied in time and frequency domains and form the basis for network analysis.
Both of Kirchhoff's laws can be understood as corollaries of Maxwell's equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits.

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1. ### Exploring Quadripole Interconnected with External Circuit

Hello, I'm struggling with the conditions under which makes sense employ a two-port 'external' representation of a quadripole (four-terminal electrical network) when interconnected to an external circuit (to take it simple assume a linear + permanent electrical network). Starting from circuit...
2. ### Engineering Kirchoff's voltage law applied to this circuit with three loops

I'm stuck straight out of the gate any help is really appreciated

4. ### Finding the Current in a circuit

Homework Statement The diagram below shows a circuit where; R1 = 5.0 Ω, R2 = 8.0 Ω, R3 = 1.0 Ω, V1 = 16.8 Volts, V2 = 1.5 Volts, and V3 = 39.6 Volts. What is the value of I1? In solving this problem, initially pick the current directions as shown. If the actual current turns out to be in the...
5. ### Engineering Applying Kirchoff's Voltage Law to a circuit

Homework Statement Using Kirchhoff’s rules, (a) find the current in each resistor shown in Figure P28.31 and (b) find the potential difference between points c and f.[/B]Homework Equations [/B] Σ ΔV = 0 (KVL) The Attempt at a Solution [/B] I have been trying to set up a system of equations...
6. ### Measurement Errors in Kirchhoff's Voltage Law

Homework Statement For a lab, we explored Kirchhoff's Laws. I made a procedural mistake while measuring my voltage values across my different elements. I know that all of my calculated voltage sums are correct, so I was wondering what I might have done to have loops ACBA and CDBC have almost...
7. ### Using Kirchoff's Voltage Rule to find currents in a system

Homework Statement Then solve these equations for i1-4 Homework Equations V=IR The Attempt at a Solution 80i_1-50i_2-30i_3 = -120 -50i_1+100i_2-10i_3-25i_4 = 0. -30i_1-10i_2+65i_3-20i_4 = 0. -25i_2-20i_3+100i_4 = 0. i_1=-4.18239492 i_2=-2.66455194 i_3=-2.71213323 i_4=-1.20856463...
8. ### Engineering Find Currents I1 and I2 in an Electric Circuit

Homework Statement I need to find the currents I1 and I2 in the attached image, but am having some difficulties grasping the concepts. I am given E(t) = 338sin(t) as well as values for R, L and C. I think I know what I need to use but I am not sure how to put it all together Homework Equations...
9. ### Kirchoff's Voltage Law and Current Law --

Homework Statement Homework Equations Using Loop 1, 2 and 3 The Attempt at a Solution
10. ### Optimizing Circuit Design: Voltage Range, Internal Resistance, and Wire Sizing

Hi all. In a project I'm working on I'm needing to model a DC circuit to find the required power sources/storage to keep the system voltages up to a sufficient level. There's a solar cell array, a reversible fuel cell stack, various DC "appliance" loads, and wire runs with resistances. I dug...
11. ### How does conventional current flow through the first light-bulb?

Homework Statement What way does the current flow through the first light-bulb? Homework EquationsThe Attempt at a Solution This isn't really a homework question but related ot my school work. I'm doing Kirchoff's Laws and normally I would have just thought that the current (if we use...
12. ### Calculating voltage between two points....

Homework Statement Homework Equations The voltage between any two points due to the field from a point charge q is: Kirchoff's voltage laws, which states that the total voltage around a closed loop must be zero, i.e.: The Attempt at a Solution To find V(e<-d) I used Kirchoff's...
13. ### Engineering Approach for solving voltage across a resistor in circuit?

Homework Statement I must solve for the voltage across the resistor labelled R1 in the circuit above. The values given are the resistance of each resistor, the voltage of each voltage source and the current of the current source. Note: If referring to circuit loops consider them as being...
14. ### Kirchoff's Voltage Law with Capacitor

Homework Statement Here is the problem in question. The only values given are those shown on the circuit labels. We are asked to form a voltage equation using Kirchoff's voltage law with specific loops. We were NOT asked to solve the equations for the currents. Homework Equations Sum of...
15. ### BotCan Kirchoff's Laws Be Applied to Non-Conservative Circuits?

Why can't Kirchoff's Laws be applied to a non-conservative circuit?. I'll be looking forward to a good discussion.
16. ### Calculation of equivalent resistance

Homework Statement : [/B]Given the circuit diagram, find the equivalent resistance between points P and Q. Homework Equations : [/B]ΔVloop = 0, ΔIjunction = 0 and V = IRThe Attempt at a Solution : [/B]Eliminating the wires with no resistors and solving for resistance gives me the answer as...
17. ### Power dissipated by a resistor in a circuit

Homework Statement Homework Equations P = V^2 / R 1/Rt = sum(1/Ri) (parallel) The Attempt at a Solution [/B] Since all the answer choices express the solution in terms of V^2 / R, I tried to find the voltage drop across resistor #2 to find the power. I collapsed the two parallel...
18. ### Finding Voltages in a Circuit with Nodal Analysis

Homework Statement Homework Equations KCL: Σi = 0 KVL: Σv = 0 The Attempt at a Solution Using KCL: 15 = (v1)/8 + (v2)/4 Using KVL: (v1) - (v2) = (I2)R + 10 (v1) - (v2) = (I2)2 + 10 (I2) = (v1)/8 (v1) - (v2) = (2)((v1)/8) + 10 (v1) - (v2) = (v1)/4 + 10 Now there are two variables and...
19. ### Why Are Currents Through 3 and 4 Ohm Resistors Zero in an Open Circuit?

Homework Statement Find the value of v1, v2, vab, vbc, vca. See picture Homework Equations Kirchoff's Law The Attempt at a Solution Is it true that both current through 3 and 4 ohm resistors are zero? The way I think of this is if they aren't zero, there would be charge building up at a...
20. ### Electrical Systems Modeling (finding current and voltage drops)

Homework Statement Hello! I've been really unsure of whether my solutions to the first problem and part (b) of the second are right. My book gives few examples and so I've been trying to look on other websites for resources. Sorry if this is a lot, but any and all help would be appreciated...
21. ### A Question about Kirchoff's Voltage Law

Hello Guys My Question about Kirchoff's Law is : why in this Example we considered that E2 is a Voltage Drop not a Voltage Rise ?? i mean why we didn't say that : +E2-V1-V2+E2=0 ? and Thanks Guys :)) !
22. ### Kirchoff's voltage law with coils

There is an idea that Kirchoff's voltage law could not be applied to circuit containing coils like this link. What makes me confused is that almost all books apply Kirchoff's voltage law to RL and RLC circuit.
23. ### Differentiating Kirchoff's voltage law expression

Homework Statement Differentiate V0 - iR - q/C = 0 to prove that di/dt = -i/RC. Homework Equations V0 - iR - q/C = 0 ^ derived from previous question for a circuit that had one battery with emf V0, a resistor of resistance R and a capacitor of capacitance C (all in series). di/dt =...
24. ### Contradiction between ΔV in circuits' wires and Kirchoff's voltage law ?

A simple electric circuit (such as one composed of a battery with Emf V and resistor with resistance R) is in an electrodynamic state since the battery's potential difference creates an electric field in the circuit's wires, which in turn moves charges around. So potential difference in wires is...
25. ### What is the voltage across vc(0)?

What is the voltage across vc(0) in the diagram below? The solution says its 10V but I don't know how they got that. Through KVL, I got 0V. Since all the current flows through the left most circuit, iA = 10/1000 = .01A 3k and 1k(right) resistors have no current. -10 + 1000iA + vc = 0 vc =...
26. ### Kirchoff's Voltage Law in RLC circuit

Homework Statement I am required to write KVL circuit equations for the following circuit I don't need to finish solving for I1, I2, I3 and I4 at the moment. I just need a bit of help setting up the equations. Thanks. Homework Equations Kirchoff's Voltage Law, which states that...
27. ### Help me, to understand kirchoff's voltage law.

N.B: I was trying to apply kirchoff’s voltage law to this ckt diagram. (created by myself :smile:) To apply kirchoff’s voltage law: 1) Assume current along with their directions in each branch of the ckt. (Assumed: and represented by arrows (red for I1 and violet for (I1 +...
28. ### Inductance in Kirchoff's voltage law

Hi, when summing the votages when using Kirchoff's voltage law around some loop, why do anywhere they take L(dI/dt) as the voltage fall on the inductance (if we sum the voltage in the current direction)? If I understand well , if there is a current in some direction, the induced voltage...
29. ### Kirchoff's Voltage Law: Circuit Troubleshooting Help

I am having trouble with the attached circuit to find the voltage drops. Can anyone please assist. Thanks
30. ### Differential equation based on Kirchoff's voltage law

a series circuit with an inductance of 15mH, a capacitance of 35*10^(-6) F and a resistance of 5 ohms conatain a sinusoidal source of emf with a frequency of 500Hz. The frequency with which the charge on the capacitor oscillates is? i think that it should still be 500Hz, right?