Electric circuits Definition and 136 Threads

  1. Z

    Find V-I characteristic for this circuit with ideal diode

    This circuit has an ideal diode, which is modeled as That is, when the potential difference across the diode is ##\leq 0## then we replace the diode with an open circuit and no current flows through it; when the potential difference is ##\geq 0## we replace the diode with a short circuit...
  2. A

    B How can scalars like voltage, impedance, etc. be added like vectors?

    So we learnt about the different types of circuits and their behaviour when connected to an alternating current source. (DC was treated as an AC with 0 frequency and/or infinte time period). For purely inductive and purely capacitive circuits we were shown the derivation and why things are the...
  3. Dario56

    I How can concentration gradient field come into existence immediately?

    Suppose there is a non-stationary diffusion process in 2D rectangular plane. Component diffuses from the outside through all four faces of the plane. When I think about the simulations of the non-stationary diffusion in Matlab for example (finite difference numerical solution), I remember how...
  4. Z

    Determine Thevenin equivalent circuit.

    Here is the circuit that we need to find the Thevenin equivalent of I am really not confident that the attempted solution below is correct. Let's put a test current source between the terminals we're interested in First let's compute the open circuit voltage. We set the newly introduced test...
  5. electricx

    What causes voltage between AC Mains phase and me?

    So my question is that if i put other lead of multimeter to my hand and other lead to socket 230 phase wire why it shows 150 volts when i stand at floor and 80 volts when i stand at carpet? what causes those voltages? And yes i know doing that could be dangerous. It also shows weird voltage if i...
  6. Z

    How to determine drain-source voltage for this MOSFET amplifier.

    TL;DR Summary: I took a few hours to come up with the solution below. The problem isn't the math or anything, but rather the concepts involved. We are asked to find the relationship between two voltages in a MOSFET operating under different conditions. The MOSFET in the circuit below is...
  7. brotherbobby

    Name of software for drawing electric circuits

    I loved working through Alexander and Sadiku's book Fundamentals of Electrical Circuits. However, what attracted me the most about the book was the way the authors drew the electrical circuits. I copy and paste two typical drawings, hoping I am not violating anything. Does anyone know the...
  8. D

    Classical Looking for a textbook that uses the electromagnetic wave view of electric current

    So I watched a couple of videos on Youtube with the titles 'How Electricity Actually Works' and 'The Big Misconception About Electricity' ( and ). The main message being that while the view of current being the flow of electrons might be useful practically, it's not an accurate representation...
  9. Z

    Understanding dependent sources in electric circuits

    The amount of voltage provided by an independent voltage source and the amount of current provided by an independent current source do not depend on the circuit they are in. There are other types of sources, however, that do depend on the circuit they are in. That is, such dependent sources...
  10. Z

    How to find the equivalent resistance of this infinite circuit?

    TL;DR Summary: I am following the course 6.002 "Circuit and Electronics" on MIT OCW. There are no solutions to the problem sets. I would like to check my solution to one particular problem. We are asked to find the equivalent resistance of the network as viewed from its ports. I simplified...
  11. Dario56

    I Is the Poynting Vector Field the Only Factor in Energy Flow in Circuits?

    In a simple circuit consisting of a battery and a resistor, current will flow if the circuit is closed. Resistor uses the energy provided by the battery, creating heat with a power ##P = UI##, where ##U## is a voltage across the resistor and ##I## is a current through the resistor. In my...
  12. Dario56

    I How is Potential Difference Created across a Resistor?

    In a simple circuit consisted of a battery and a resistor, how is potential difference actually established on the resistor? My understanding is that battery creates the electric field which propagates through space at the speed of light. Resistor is put inside this field and therefore...
  13. Z

    I Is this example incorrect in Agawal's book on electric circuits?

    Consider the following circuit In Example 2.14 of Agarwal's "Foundations of Analog and Digital Electronic Circuits", he asks us to determine the value of v using energy conservation. The result in the book is ##v=0.5\text{V}##. This seems incorrect according to my calculations. I am...
  14. H

    B Where Do Electrons Go When a Battery Loses Charge?

    I am no physicist or student and am asking question in order to out try and understand why my old tractor is not charging. This got me into understanding the concepts of how the generator and voltage regulator work to create a current to charge the battery. My investigations pulled me down in...
  15. V

    An electric circuit problem involving 5 current variables

    I came up with the following set of equations. I try to express all currents in terms of ##I_1## and then substitute in the first equation to get the value of ##I_1##. Since ##I_4## needs to be determined and I have already expressed it in terms of ##I_1##, so it can be calculated. The problem...
  16. Franklie001

    AC circuit analysis involving resistors and inductors

    Summary:: Hi anyone can explain me how to solve this circuit, finding the current I2 and I1? Really don't know where to start Thanks
  17. Dario56

    I How is Potential Difference Created in Electrolytes?

    When we have a resistor in electronic conductors, potential difference is created via surface charges which accumulate on conductor surface. What about electrolytes? I am not sure if electrolytes can create potential difference in the same way since surface in electrolytic conductors isn't as...
  18. Dario56

    Internal Resistance of the Battery - Ohmic Resistance

    When current starts flowing in a circuit, voltage of the battery drops from EMF value. There are three sources of this however here I am only interested in ohmic resistance of the battery. EMF of the battery is created because of electrochemical processes on both electrodes which create...
  19. J

    How does the current divide in parallel inductors?

    I apologize using English fluently because I am not an Enlgish speaker. When I tried to solve this problem, I used current divider rule. So, $$i_o(t) = \frac{3}{3+5}*4e^{-2t} = 1.5*e^{-2t} A$$ However, This was wrong. The answer is $$ 1.5*e^{-2t} + 0.5 A$$ If I use $$V_O = L*\frac{di}{dt}$$...
  20. W

    Is seeing believing in physics?

    I am new here and I am not going to say I have any formal schooling in physics or electrical engineering. I have been in the automotive field for almost 40 years. What I am getting at is, myself and my research partner came across a very unusual circuit about 4 years ago. We spent about 3 years...
  21. Paola Flores

    Engineering Fundamentals of Electric Circuits - Sadiku Question on KVL

    Hi, this is my first time posting, I'm glad there is a space like this where we can share our doubts and hopefully get some help from other students. As you can see on the image above, there's a KVL applied to the circuit in practice problem 2.6, but my question is the following: On equation...
  22. MermaidWonders

    MHB What's the difference in resistance between A and B vs A and C?

    I tried redrawing the above circuit so that it resembles more like the circuit diagrams we see from day to day. However, what confused me was when it asks for the resistance measured between A and B versus between A and C What's the difference between those two, and how would the calculations...
  23. Alettix

    Capacitor filled with two conducting materials

    Homework Statement a) State the boundary conditions for the electric field strength E and electric flux density D at a planar interface separating two media with dielectric constants ε1 and ε2. b) A parallel plate capacitor with a plate separation d is filled with two layers of different...
  24. S

    Ideal conditions in which circuit analysis is done

    What are the ideal conditions in which circuit analysis or analysis of an electrical system is done?I know that the air friction,friction between materials is ignored in ideal systems, such as for ohms law applications.What else is ignored in analysis of ideal electrical systems?
  25. G

    What Causes Maximum Joule Heating in a Resistor Circuit?

    Homework Statement 2. Homework Equations [/B] Consider the following circuit where: $$R_A=330 k\Omega$$ $$R_B=220 k\Omega$$ $$C= 2.2 nF $$ $$v_1(t)=6u(t) V$$ $$ i_2(t)=-10u(t-t_2) \mu A$$ $$t_2 = 12 ms $$ All the currents go clockwise (with the obvious exception of the current source)...
  26. R

    I Lagrangian method for an LC-Circuit

    In the paper http://physics.unipune.ernet.in/~phyed/26.2/File5.pdf, the author solves the LC-circuit using Euler-Lagrange equation. She assumes that the Lagrangian function for the circuit is $$L=T-V$$ where $$T=L\dot q^2/2$$ is the kinetic energy part $$V=q^2 / 2C$$ is the potential energy.She...
  27. S

    What is the best software for the analysis of chaos in electric circuits?

    What is the best software for the analysis of chaos in electric circuits.
  28. C

    Electric circuits -- Finding the V-I characteristics of a light bulb

    Homework Statement Homework EquationsThe Attempt at a Solution I know Ammeter and bulb goes in series and Voltmeters in parallel. But am I supposed to connect the voltmeter to the little arrow on the potential divider, or just across the bulb?
  29. Vectronix

    Lightning striking electric circuits

    Why does lightning seem to hit objects with free electric currents inside (like computers or cell phones) more than "neutral" objects?
  30. Ali Zain

    Rank in order, from largest to smallest, the resistance (eq)

    Homework Statement There is a figure, I'll try my best to draw/describe. 1. All three resisters are in parallel ___R____ !___R____! !___R____ ! 2. 2 resisters are parallel and one in series, after the parallel (ignore the dots) ___R___ ... _____R___ !___R___ ! 3. 2...
  31. U

    Engineering Electric circuits methodology question

    Homework Statement Homework Equations The Attempt at a Solution My problem lies in when I get equations like: and if I plug in Vi and its derivative, I get equations like: How do I solve for t in these equations if I have a sine and a cosine term that contain t?
  32. solour

    Reducing all circuit resistors to only parallel and series?

    Homework Statement The problem from the textbook is: Is it possible to connect resistors together in a way that cannot be reduced to some combination of series and parallel combinations? Homework Equations V = IR kirchhoff's current law kirchhoff's loop law The Attempt at a Solution I am...
  33. Asmaa Mohammad

    Determining the total current of many batteries

    Homework Statement The figure represents a part of a circuit, and the potential difference between the f and d is 12Volts, depending on the information shown in the figure, determine: 1-the reading of the Ammeter 2-the value of (Vb)₃ 3- the potential difference between (c , b) Homework...
  34. G

    Water model for electric circuits: Pipe diameter?

    Hi. There's this nice water circuit model for electric circuits where pressure corresponds to electric potential and the (mass or volume) flow rate to electric current. In the water model, we can vary the pipe diameter along the circuit. Since water is practically incompressible, the flow rate...
  35. M

    Use KCL and KVL to find the power supplied by the two ideal sources

    Homework Statement The Question wants to find the Voltage Across The Current Source 2A and 5A Homework Equations KVL KCL Ohm's Law The Attempt at a Solution I tried to Using KVL and KCL for all Closed paths and node but I just Couldn't Figure how to relate them to find the voltage across the...
  36. V

    Engineering Electric Circuits - Superposition and Mesh Analysis

    Homework Statement Exercise 4.15 on the image. The exercise asks for the value of the current I using superposition Homework Equations Superposition theorem, nodal and mesh analysis The Attempt at a Solution I think i am doing the mesh analysis wrong, but can't see where. Can someone...
  37. V

    Engineering Electric Circuits problem - Superposition

    Homework Statement The problemas statement is: "Find Vo and Io by the superposition principle" Homework Equations Nodal Analysis and The Superposition Theorem. The Attempt at a Solution So, I tried to shutdown first the independent 30V tension font. It led me to Vo = 8V. Then, turning off...
  38. G

    Second order derivatives and resonance

    Homework Statement 2. Consider an electric circuit consisting of an inductor with inductance L Henrys, a resistor with resistance R Ohms and a capacitor with capacitance C Farads, connected in series with a voltage source of V Volts. The charge q(t) Coulombs on the capacitor at time t ≥ 0...
  39. M

    Series and Parallel Combination

    [Note: Thread has been moved to the homework forums by a mentor] This is the Given problem This is my solution part 1 - What I did here is I series the R3 and R4 (R3 + R4), and I parallel the R34 to R5 (most of the calculation are from the calculator) This is my solution part 2 The...
  40. John Pang

    Voltage drop in an electric circuits

    I don't understand why the voltage drops only when the charges in an electric circuitnpass through resistors or electric devices, but don't drop as charges move through the wire. As charges move through the wire due to electric potential differences, from a high potential to a low potential...
  41. lucasLima

    Help calculating the voltage in a capacitor when t->infinite

    Hello Everyone! So, I need to calculate the voltage in the capacitor, let's call it Vc(t). For t=0- I know that there is no current in the capacitor. Did some calculations and I've found that Vc(0)=6v. Now i need to know Vc(infinite) But when the switch key is opened and the time goes to...
  42. alexandria

    Examining electric circuits and deducing current and voltage

    Homework Statement Homework Equations equations listed below in chart The Attempt at a Solution here is my answer, i just need to know if I am doing this correctly, thanks :)[/B]
  43. Mr Davis 97

    How electric circuits really work

    I've been studying circuits, but I can't find any resources that really answer my specific questions. So far I understand that a battery creates a potential difference between the two terminals, one of which is positive while the other is negative. There is a buildup of positive charge on the...
  44. A

    Finding equal potential points in electric circuits

    Hi! I have a real problem in understanding the use of symmetry for finding equal potential points in nasty electric circuits. There are lots of problems were the solution simply says: "due to symmetry reasons, nodes X and Y have equal potential", but I rarely really understand the so called...
  45. Sam19KY

    Question about electric circuits ?

    If the current is 0.5 A and the battery supplies 6 joules of energy to each coulomb then will it supply only 3 joules per half coulomb ?
  46. Domenico94

    What are the limitations of using electrical circuits to solve PDEs?

    Hi everyone. In electrical engineering, when you study control theory, you're taught that electrical circuits can be used to simulate the behaviour of complex systems. What I don't understand is, what are the limitation of this sistem, and why it can't be obviouslly used in a general way to...
  47. A

    Find the equivalent resistance between AB

    Homework Statement Find the equivalent resistance between AB. Homework EquationsThe Attempt at a Solution I could not find any Wheatstone bridge or series parallel combination. Should I use star delta transformation ? If yes, how exactly should I use it ?
  48. Domenico94

    How do you apply the wye delta transformation in complex electrical circuits?

    Homework Statement What can be special cases, in the study of electrical circuits, in which one can not apply wye delta transformation? Can someone graph them in some way? Homework EquationsThe Attempt at a Solution
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