What is Electrical circuit: Definition + 86 Threads

An electrical network is an interconnection of electrical components (e.g., batteries, resistors, inductors, capacitors, switches, transistors) or a model of such an interconnection, consisting of electrical elements (e.g., voltage sources, current sources, resistances, inductances, capacitances). An electrical circuit is a network consisting of a closed loop, giving a return path for the current. Linear electrical networks, a special type consisting only of sources (voltage or current), linear lumped elements (resistors, capacitors, inductors), and linear distributed elements (transmission lines), have the property that signals are linearly superimposable. They are thus more easily analyzed, using powerful frequency domain methods such as Laplace transforms, to determine DC response, AC response, and transient response.
A resistive circuit is a circuit containing only resistors and ideal current and voltage sources. Analysis of resistive circuits is less complicated than analysis of circuits containing capacitors and inductors. If the sources are constant (DC) sources, the result is a DC circuit. The effective resistance and current distribution properties of arbitrary resistor networks can be modeled in terms of their graph measures and geometrical properties.A network that contains active electronic components is known as an electronic circuit. Such networks are generally nonlinear and require more complex design and analysis tools.

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1. How does this potential divider circuit work?

The correct option is supposed to be (B). Can someone please explain why changing the resistance of the variable resistor affects the voltage across the other resistor? Also explain why (B) is the correct option? Thanks
2. Window fan: Bypassing thermostat with a button

I bought this window fan for my work shed. Installed it on a nice, mild day. Next day fan wouldn't work. Almost took it back to the store before realizing the day was much colder. The fan is on a thermostat - one that's probably set for summer, not winter. So, I want to be able to operate it in...
3. Find spring constant k using an electrical circuit

This circuit consis of two identical, parallel metal plates free to move, other than being connected to identical metal springs, a switch, and a battery with terminal voltage ##\Delta V##. With the switch open, the plates are uncharged, are separated by a distance ##d##, and have a capacitance...
4. Help Needed for Solving Electrical Circuit Problem

What I have done: (1) ##I(0)=\frac{V}{R}=\frac{1.5}{25}A=0.06 A.## (2) By setting ##I(t*)=0.06(1-e^{-(35/0.4)t*})=35 mA## we get ##t*\approx 0.01 s## What I have done seems correct to me, but the result for part (2) should be different. I would be grateful if someone could point out to me...
5. I Do electrons flow in an electrical circuit?

The video on youtube on the above link seems to imply that electrons don't flow through a circuit. At 01:29 into the video, the narrator says that he used to teach his classes how electrons move through a circuit by using a clear plastic tube with a chain inside of the clear plastic tube. The...
6. Engineering AC Circuit Phasors: Find I1, I2, I3

Summary:: Hi, I tried attempting this problem in alternating current in order to find out the phasors as complex numbers, and I would be more than grateful if someone could peer review it, and confirm my calculations (Please see below both the Figure and the calculations) Please find attached...
7. Electrical circuit problem (resistors, capacitors, inductors )

I did try redrawing the circuit at steady state , but I'm not really sure. I have attached the circuit that I tried drawing, I assumed the branch with the capacitors to be absent at steady state since current won't flow through them anyway. With this diagram I get the correct answer for Q 19 ...

9. Help designing an electrical circuit for camper van

Hi everyone Hopefully I am not out of line posting in this forum. I am looking for some advice planning the electrical system for my camper van. I know very little about electrical circuits and all related to it, and after 4 days of research I am still nervous to spend a lot of money and...
10. How to determine the power of this circuit?

In "Homework Equations" field, I wrote general equations for quadripole. I have doubt about the solution. True answer given in the electrical engineering textbook is P = 100 W. Here is my solution: 1) In scheme, I pointed currents and U(output) (Fig. 2). 2) U = A*U(output) + B*I2 I1 =...
11. Solving a Perplexing Thought Experiment: A DC Electrical Circuit

This thought experiment has been bugging me for a very long time - I'm hoping someone can help me understand it. Premise: - Simple DC electrical circuit consisting of a battery, wire, light bulb, and another wire to complete the circuit. - Each wire has a length of 1 light-year (yes, very...
12. Symmetry in Electrical Circuit Analysis

How is symmetry used to solve electrical circuits? I have seen several problems in books in which currents in two resistors are said to be equal due to 'symmetry'. That is a concept that I fail to understand and thus cannot apply. In class, we were shown a few circuit diagrams which were...
13. Current Dividing in an Electrical Circuit

A circuit contains a 7.5V d.c power supply and three resistors. The total resistance of the circuit is 30 ohms. Why will the largest current in the 18 ohm resistor? As far as I know is that the smallest current will be in 60 ohm resistor because it has the maximum resistance. Please explain...
14. How to find the relative error in the voltage reading

Homework Statement For a circuit with 3 resistors in series (R1=1.00 kOhms, R2=2.50 kOhms, R3= 4.00 kOhms and Va=12.0 V). A voltmeter was placed across R2 and R3. Calculate the relative error in the voltage reading if the internal resistance of the voltmeter was a) 5000 ohms, b) 50 kOhms, C)...
15. Find the current I in this electrical circuit

Homework Statement Homework Equations V = I.R The Attempt at a Solution 6 ohm and 3 ohm are series = b Then b pararel to 9ohm = c = total resistance b = 9ohm c = 9/2 ohm I = V/R I = 9.6/c I = 2,13 A Can you help me? Is it right? My friend's answer is 0,8
16. Why does having a high input impedance and low output impeda

Homework Statement Say you connect Circuit A with low output impedance to circuit B with high input impedance. Why does this cause minimal voltage drop compared to connecting them the other way around (high output to low input). Homework Equations P = V^2/R P = IV The Attempt at a Solution I...
17. Relating resonant frequency to electrical impedance

If a self oscillating electrical (passive) system is excited at two nodes A and B by a sinusoidal current, and if this system has one degree of freedom, then the response of the system is maximal at the resonance frequency. Quantitatively, this means that the ratio of the exciting complex...
18. I Electrical circuit differential equation

q''+ 20 q = 100 sin(ωt) I have been asked to find all mathematically possible values of ω for which resonance will occur. From the homogeneous solution, q(t) = Acos(√20 t) +Bsin(√20 t), I can see that resonance occurs when ω=√20. My question is, should I also consider -√20? And if so, what is...
19. Electrical Circuit Problem / Electric Potential Difference

Homework Statement In the following picture, the absolute value of the difference in electric potential, between points A and B is: A)5V B)4V C)3V D)1V E)0V Homework Equations E =qV V = iRThe Attempt at a Solution I have no idea where to start on this one, just started my electric circuits...
20. I What causes confusion in testing time invariance?

I understand what time invariance means but there are a few catches that I'm completely confused about: Suppose we have $$y(t)=x(\alpha t-\beta)$$ to test time invariance we shift the input then "plug" it into the output:$$x_1(t_1)=x(t-t_o)$$ so this is when I become confused; when we plug...
21. How to convert movemnt/speed to electricity or other E.forms

Hi I was wondering if there is a way to produce energy using the movement of vehicles on the road. I do not know which principles can come into picture, but I believe Electromagnetism/ detection is the way to go? If someone could at least throw me in the right direction of which field to...
22. Help with OP AMP Circuit Question

hi, i reallyt need help in this question. i tried this but i am not sure how to start this, so if you can provide me little help i will really appreciate it its based on OP AMP circuit thanks guys
23. LaTeX Draw Electrical Circuits Free in Tikz w/ GeoGebra

Can you suggest a free program that allows you to draw electrical circuits and export them in latex through tikz package (like geogebra)?
24. How to find the voltage 'v' in the given network?

Homework Statement Homework Equations [/B]The Attempt at a Solution
25. Electrical circuit Source transformation Question

I'm extreeeeamly rusty at basic circuit theory. I want to transform a sort of infinite arrangement of this circuit: The values themselves aren't important, just the representation of what's happening, all the verticle resistors are the same value as each other, and all the horizontal resistors...
26. Engineering Current in Series Circuit: 2V, 3V, 5V, 4Ω, 2Ω

Homework Statement Find the current for the next circuit. Consider the values given: V1= 2 V, V2=3V, V3= 5V, R5= 4Ω Y R4= 2Ω Homework Equations RT=R1+R2+R3+Rn I=V/RT P=VI=V^2/R The Attempt at a Solution My attempt of solutions is to sum the first two voltages and divide it between the first...
27. Solving Complex Electrical Circuit: V1, V2, & V3

Homework Statement Homework EquationsThe Attempt at a Solution I assumed there to be two supernodes. The first one was between V1 and V2. The second supernode was between V2 and V3. This is what i tried and i am not getting the right answers. Please can someone help me out! Apologies...
28. Electrical Circuit Calculations

Homework Statement Calculate the individual currents in I2 and I3 (See diagram). I basically need to know how I calculate the current at any point in that circuit and that would help me. Homework Equations V=IR Rseries=R1+R2... 1/Rparallel=1/R1+1/R2 The Attempt at a Solution I honestly have no...
29. Kinda tricky item in a question about an electrical circuit

I'm trying to solve item "c" of this question about the electrical circuit depicted on the attached picture. The question is in Brazilian Portuguese, this would be a rough and not 100% gramatically correct translation: "In the circuit shown below on Pic. 1 (labeled "Electrical Circuit")...
30. Energy flow in an electrical circuit

Hi, could someone explain how energy and voltage operate in an electrical circuit. I'm really confused because I was reading a book on misconceptions in electric circuits which said that energy is not associated with the charges in a circuit. It goes on to say that if it did then you would have...
31. Which Electrical Circuit Simulator is Recommended for New EE Students?

Hey! Are there any good softwares for PC that can simulate electrical circuits that you can recommend? /A new EE student.
32. MHB Setup an Electrical Circuit - Guidance Needed

I haven't set up a DE for an electrical system since 2008 so I need some guidance until I get the hang of it again. The circuit in question is: http://imagizer.imageshack.us/v2/800x600q90/594/0sze.png
33. Engineering Is the Unknown Circuit Component a Resistor or a Voltage Source?

Homework Statement The circuit has an unknown component that is a resistor or a voltage source, find which one it is and it's value. Homework Equations V=IR, KVL, KCL The Attempt at a Solution I first used KVL on the outer loop: 14-2I1-10=0 I1=2A Then on the...
34. Finding the Best Electrical Circuit Theory Book

Which is the best book for electrical circuit theory?
35. Electrical Circuit Analysis vs General Physics w/ Calculus

Hi. So, currently I'm a senior in high school taking classes at the community college (my high school is paying for them) and I am having trouble deciding between these two courses. I learned that General Physics w/ Calculus doesn't actually have that much calculus, and I already learned a...
36. Name of this electrical circuit?

Hi, I'm woundering whether this circuit has some kind of dedicated name in the field? https://dl.dropboxusercontent.com/u/22589354/VoltageDivider2.jpg It's not just the average voltage divider as it it influences the serial part as well the parallel part in the same time. And does...
37. Engineering Electrical circuit related problem

Homework Statement Determine the value of the voltage Vx across the 3A current source. Homework Equations The Attempt at a Solution I am really confused about how to do it. What I thought of is to find the voltage across the 4 ohm resistance which is 12 V. I though of subtracting...
38. Electrical Circuit Question - Integrating Amplifier

Homework Statement http://img801.imageshack.us/img801/4227/capturebsw.png Homework Equations The Attempt at a Solution Alright I'm not really sure how to solve this problem. I have redrawn the circuit below without the operational amplifier. In ideal operation amplifiers there's no...
39. What are the Currents in a Multi-Level Parallel Circuit with 6 Leads?

A branch of multi-level parallel circuit has 6 leads coming into it and currents of 3 A, 4.4 A, and 8.8 A flow into it, and one of the leads has a current flowing out of it of 6 A. If the other two leads have identical currents flowing out through them, what are those currents? Any help would...
40. A strange electrical circuit - resistance calculation

Hello. So I've got an electrical circuit on page 4 of this: http://www.iuventa.sk/files/documents/2_olympiady/fo/54.%20rocnik%202012-2013/ulohy%20a%20riesenia/skolske%20kolo/f54skcul13.pdf and I am to calculate the total resistance of the circuit, but I have no idea on how to solve that strange...
41. Engineering Electrical Circuit Question - Maximum Power Dispated in Resistor

Homework Statement http://img855.imageshack.us/img855/6951/captureaww.png Homework Equations The Attempt at a Solution Is one allowed to find R_{Th} by simply short circuiting all voltage source and opening all current sources and finding the equivalent resistance while keeping...
42. Engineering Nodal Analysis on Electrical Circuit

Homework Statement The Attempt at a Solution According to the similar problem Node X: I1=(22-Vx)/66 I2=(66-Vx)/44 Il=Vx/264 I3=I1+I2+Il Node Y: I4=Vy/240 I5=6 I4=I3+I5 After the calculations I get 1.08 for Vx, which I think is wrong. Thanks
43. What is the validity of this electrical circuit?

http://img15.imageshack.us/img15/771/captureuce.png Homework Statement Determine if the circuit is valid or invalid. Homework Equations The Attempt at a Solution Please note which node I used as the ground node and which node I have labeled V_{1}. By the node voltage method...
44. What Is the Relationship Between Voltage and Length in an Electrical Circuit?

Homework Statement So I was wondering if someone could help with part C. I have gotten the answers for A and B, at least I hope they are correct. Homework Equations The Attempt at a Solution So I'll just do the rectangle first and then try and solve the trapezoid. By the way...
45. Engineering Electrical circuit porblem using ohms law

Homework Statement Using all the following resistors : 2 x 12 ohms , 2 x 24 ohms , and 2 x 36 ohms. create a circuit where the total resistance will be 4 ohms. The problem states that I have to use ALL of the resistors..making it so complicated Homework Equations 1/Req = 1/R1 + 1/R2...
46. Calculate the Ratio of Ib/Ia in an Electrical Circuit

Homework Statement Part of an elecrial circuit for the olympic score board consisted of a single battery V and several resistors having on of two values. R or 2R. They are hooked up in the confriguration as shown. Calculate the ratio of the two currents shown Ib/Ia...
47. Solving Electrical Circuit Puzzle: Voltmeter & Transistor

Homework Statement http://web.stagram.com/p/362176186041336029_243276631 this is a link to the question. I'm stuck on 2a and b Homework Equations I don't understand if the voltmeter is reading 6v why the light is not receiving 6v? And why would a transistor help this problem? The...
48. Engineering Use KCL to solve a Very simple electrical circuit

Homework Statement Given I0=-2 A I1=-4 A Is= 8 A Vs= 12 V Find all the unknown currents. http://sphotos-a.xx.fbcdn.net/hphotos-snc7/398253_493549703997883_2004542070_n.jpg Homework Equations Kirchhoff’s current law The Attempt at a Solution I start at node a and found I2= 6 A and then...
49. Engineering Designing a Multi-Setting Stove Using Resistive Heating

Homework Statement Your first assignment with the Holmes Electronics Company is to help us design an efficient stove using resistive heating. Our market research tells us that the stove needs four heat settings: Hi, Med-2, Med-1, and Low. The Hi setting needs to have an electric power of 3...
50. Electrical Circuit Drawing Software

Hello, I am writing my MSc dissertation, and I want to draw some 3-phase circuits with different cabling configurations (6-wire, 4-wire etc). I need an easy software that can draw the schematics nicely, like the ones found in books. I do not need interactive software (like NI circuit design)...