# 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.

617 questions
Filter by
Sorted by
Tagged with
1 vote
83 views

### Does KVL guarantee identical voltages/currents in similar circuits?

I have a question that is a bit abstract. Assuming I have two proper linear circuits, A and B, which have: The same ideal components (for example, voltage source, inductor, capacitor, resistor) The ...
• 240
317 views

### Is it correct to apply KVL through the 2 inputs of an op amp?

The question asks; "P14.25 Analyze each of the ideal-op-amp circuits shown in Figure P14.25 to find expressions for 𝑖𝑜. The top part is the question, the bottom is the solution from the ...
41 views

### KVL and KCL for an RLC circuit

I have a circuit for a resistor $R$, inductor $L$, capacitor $C$. I also have two sources of power, $u_1(t)$ and $u_2$. My task is to set up a state equation for the circuit, and I ...
135 views

### Application of Kirchhoff's voltage law to a section of a circuit

I have to write an equation for calculating value of current on the circuit section. Let's say that direction of bypassing the circuit was chosen the same as direction of current on the figure. I ...
79 views

### I am analyzing this circuit using KVL

I am analysing this circuit using KVL. My doubt is while writing the loop equation what will be correct format. $$70-V_x - 2V_x- V_o =0 \: \: \: \text{or} \: \: \: 70-V_x-2V_x + V_o = 0$$ Please ...
40 views

### Using Kirchhoff's voltage law for calculating S-parameters

Consider the following circuit: for which I'd like to calculate the S-parameters of the impedance $Z$ (and assuming $Z_G$ = $Z_L$ = $Z_0$). Will it be correct to use the Kirchhoff's voltage ...
• 101
1 vote
69 views

Does negative current mean the flow of negative charges? If so where do the positive charges from I_1 and I_3 go after reaching the blue node on the image below? I do not understand how the positive ...
• 27
72 views

104 views

### 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 ...
• 43
102 views

### 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 ...
130 views

### 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 ...
179 views

### 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: $$-120\ \mathrm{V}+I_0\cdot 10+I_1\cdot 50 = 0$$ ...
• 13
81 views

### 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, ...
1 vote
78 views

### 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 ...
• 13
690 views

### 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 ...
74 views

### 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?
165 views

### 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 ...
57 views

### 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 ...
• 19
82 views

### 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 ...
• 133
32 views

### 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 ...
• 19
82 views

### 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 ...
99 views

### 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 ...
• 137
70 views

### 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 ...
• 137
486 views

### 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 ...
• 137
1 vote
137 views

### 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 ...
• 133
1 vote
119 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 ...
• 149
91 views

### 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.
129 views

### 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 ...
• 147
48 views

### 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 ...
184 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 ...
307 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 ...
34 views

### 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+...
• 3
1 vote
106 views

### 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'...
204 views

### 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 ...
• 3
48 views

### 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:...
• 103
81 views

### 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 ...
338 views

### 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 ...
• 557
270 views

### 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 ...
94 views

### 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 ...
1 vote