What is Circuit: Definition and 1000 Discussions

A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by excess current from an overload or short circuit. Its basic function is to interrupt current flow after a fault is detected. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.
Circuit breakers are made in varying sizes, from small devices that protect low-current circuits or individual household appliance, up to large switchgear designed to protect high voltage circuits feeding an entire city. The generic function of a circuit breaker, or fuse, as an automatic means of removing power from a faulty system is often abbreviated as OCPD (Over Current Protection Device).

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  1. SaiTatter

    I need to calculate the equivalent resistance

    Homework Statement The circuit is the one in "Fig.4" I need to calculate equivalent resistance between A and B. This is what I've tried: I think that the first resistor is shorted by that wire connected between A and E. Their answer looks like this, in fig 2.2.1. I'm not sure if their...
  2. MedEx

    Finding the Current in a Resistor in a Closed Circuit

    1. Homework Statement The ideal battery in Figure (a) has emf = 7.7 V. Plot 1 in Figure (b) gives the electric potential difference V that can appear across resistor 1 of the circuit versus the current i in that resistor. The scale of the V axis is set by Vs = 18.9 V, and the scale of the i...
  3. paulmdrdo

    Engineering RC-RL Circuit: Solving for Capacitance Value

    Homework Statement [/B] 2. Homework Equations 3. The Attempt at a Solution In got stuck. I'm not sure as to what Time constant should I use to solve for the capacitance value. In the original expression for the current, both terms are exponential function. I do not know whether to...
  4. Zack K

    Mesh Analysis Method for Finding Current in a Circuit with Dependent Source

    Homework Statement Find the current in each resistor. (refer to uploaded diagram) Homework Equations ##Kirchhoff's Law: I_s=I_1 + I_2## Mesh analysis method The Attempt at a Solution I'm calling ##I_s## the total current before and after the current splitting up, and ##I_1## and ##I_2## are...
  5. Z

    Engineering Amplifier circuit driving an 8 Ohm speaker

    Homework Statement Hi all. I need a bit help with the following. Estimate the power developed in the 8 Ω speaker of the circuit of FIGURE 2 for a 1 kHz sinusoidal input signal of 100 mV peak. All capacitors may be assumed to act as a short circuit at the frequency of operation. Compare your...
  6. Toolkit

    Engineering Circuit Mesh analysis question

    Homework Statement Homework Equations I've worked out the KVL's for four meshes, I1, I2,I3, and I4. Would anyone be able to error check this for me? Also, would I be correct in thinking that I can use ohm's law by dividing V1/Z1 to find the current of the first mesh and likewise with...
  7. Kenny555

    Ohmmeter question -- Measuring a 2-resistor circuit

    Homework Statement [/B] Find reading of ohmmeter. Homework Equations V=IRThe Attempt at a Solution I am a beginner of this topic and I think it is simple as ohmmeter directly measure the resistance of the resistor which is 2k ohm while the correct answer is 1.67k ohm. I have no idea how to get...
  8. L

    How to introduce a phase shift in an AC circuit

    Hello, I am trying to think of a way to introduce a phase shift in an ac circuit. For example, sin(omega*t+theta) to change theta. How can I go about doing this? I do not think introducing a cap or inductor would work, even though it shifts the voltage from the current graphs (phasors). A...
  9. J

    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...
  10. hagopbul

    Asking about the Vcc of some integrated circuits

    Hello: I have to ask some question , did anyone know any integrated circuits that have voltage Vcc of few kilo volts what was the catagoeries of that circuits ? And do they different from high current integrated circuits ? Where to read about it ? Best hope
  11. R

    Finding the values of voltage and current in this circuit

    Homework Statement It's best if one looks at the picture of the circuit diagram. What we're given is a current of 0.25 A and two resistances of 20 and 30 ohms. Homework Equations Kirchhoff's Voltage Law, Kirchhoff's Current Law, Ohm's Law The Attempt at a Solution My attempt at a solution...
  12. T

    What is the potential at point D in the circuit

    Homework Statement I've attached a picture of the circuit below for reference, but the question is asking what the potential is at point D.Homework Equations V = IR[/B]The Attempt at a Solution I was told that the answer was 9V, but I'm a little confused because I thought if I looked at the...
  13. Abdullah Almosalami

    Constant Current Source in Driving an RC Circuit

    Alright. So I'm getting two different solutions depending on how I look at this problem, and I know one is correct but I don't know why the other would be incorrect. So, given this general circuit of a constant current source driving an RC circuit in parallel: Now, what they tell me in class...
  14. Boltzman Oscillation

    Engineering What is the output voltage of this ideal diode circuit?

    Homework Statement Given the following circuit: what is the positive and negative peak values of Vo? vi has a frequency of 1kHz, peak of 5V, and is a sine wave. Homework Equations x(t) = Vsin(2(pi)*f*t) KCL, KVL, etc. The Attempt at a Solution [/B] I made Vi to be 5sin(2(pi)1000t) during...
  15. M

    Engineering Nodal analysis of an AC circuit

    Homework Statement Hi I have this question as part of my assignment but cannot get my head around part b, I have worked out part a with an answer of -9.2+17.3i amps which from a previous thread I know is correct, but can't understand why the equations given in the previous thread are different...
  16. S

    Correct statement about series RC circuit

    Homework Statement The battery is disconnected from a series RC circuit after the capacitor is fully charged and is replaced by an open switch. When the switch is closed, a. the capacitor does not allow current to pass b. the current stops in the resistor c. the potential difference across the...
  17. J

    B Help with math in a quantum circuit

    Hi! Sorry for the bad English! I'm trying to get a better understanding in quantum mechanics by doing the math of quantum circuits and I'm stuck! So, please, if someone can, help me! =) I'm trying to the math of this circuit: q0 ... l 0 ) .... x ... (I) q1 ...
  18. R

    Please could someone critique my circuit schematic (simple)

    Hi, I am just putting a simple representation of my equipment in a type of circuit schematic as part of my set-up figure. Please could someone who is more experienced than myself tell me if there is anything wrong with it / any suggestions. Thanks in advance for any help...
  19. Jason-Li

    Thevenin's Theorem, Superposition & Norton's Theorem

    Homework Statement FIGURE 1 shows a 50 Ω load being fed from two voltage sources via their associated reactances. Determine the current i flowing in the load by: (a) applying Thévenin’s theorem (b) applying the superposition theorem (c) by transforming the two voltage sources and their...
  20. Boltzman Oscillation

    Engineering How to analyze a circuit with one node using the node method

    Homework Statement I have the circuit given below with a single node where R3 and ground meet. How can I solve this problem using the inspection method? Is it possible? I can easily solve using another method but I would rather try using the inspection method. Homework Equations Ax = M A is...
  21. E

    Puzzled by how the Voltage is the same across different points

    If this is better for the HW section please tell me, sorry about that. So Voltage is the change in potential. I'm puzzled by how potential in circuits is the same along different points until we reach a resistor - at which point the potential changes. As in, if we take two points before a...
  22. dvscrobe

    Engineering Time Constant of an Opamp Circuit

    Homework Statement : [/B] Find the time constant of an inverting op amp with C = 50uF, Ri = 200 Ohms, Rf = 20 Ohms. This is a problem I have found in a prep book for the Fundamentals of Engineering Exam (Electrical component). The book gives the answer as time constant = Rf * C. I am not...
  23. Eduardo Leon

    Energy dissipated in the resistors in a 2 mesh RC circuit

    Homework Statement Hi mates, I have problems solving the third part of this exercise, I've already done all the previous calculations. Given the following circuit, where the switch S is open, the power supply = 50 volts and: The initial charge in the C capacitor: QC = 0 coulombs The initial...
  24. F

    Engineering What Is the Correct Probability Calculation for a Quantum Circuit Measurement?

    Homework Statement input state is |1>(tensorproduct)(2|0>+|1>). Homework Equations Find the probability of the outcomes being 0 and 1 measuring the second qubit. And then what the outcome states of each are. The Attempt at a Solution I have attempted this problem and for the probability of...
  25. Shivang kohlii

    Time constant for parallel RC circuit

    Homework Statement Question 6. Homework Equations Time constant = RC The Attempt at a Solution I think answer should be 1/2 RC as Rnet = 1/2R and to convert it to single resistance form we should first find Rnet But the answer is coming out to be RC . How? << Corrected Image added by...
  26. Z

    Help Understanding Circuit Requirements for Conducting Diode

    Hi all. I need some help with the circuit attached. For the diode to conduct, at point X the voltage must be 0.6V minimum. There is an equation to find the minimum required voltage input, Vin to give 0.6V at X. What I don't understand is the right hand side of the equation; why is it...
  27. DLeuPel

    Calculate the voltage in a circuit

    Homework Statement Given the following circuit, find the values of V1 and V2. Homework Equations The second law of Kirchhoff states that the sum of all voltajes must equal 0 The Attempt at a Solution I found in the book that the solution is V1: 15V and V2: 14V I tried to solve V1 by adding 9...
  28. dothep6

    Does a series circuit have branches?

    Does a series circuit have branches? or the term branch can use in series circuit too and there are only one branch in series circuit. please explain.
  29. F

    Engineering Design a logic circuit to add two 2-BCD decade numbers

    Homework Statement Homework Equations - The Attempt at a Solution Here's my work : When I added 0000 0001 to 0000 0000 , I didn't get the correct answer . Could someone check where is my mistake please ?
  30. F

    In a circuit, what causes current to go from L1 to L2?

    The photograph above this sentence is a photograph of a simple 2 leg circuit of alternating current with a light switch and a light bulb. I know how alternating current constantly switches direction from line 1 to line 2 and then goes from line 2 to line 1, etc. In the diagram in the above...
  31. I

    Calculating Short Circuit Current: Tips & Advice

    Good evening to everyone! I'm pretty new in this kind of job, so every help or advice will be helpfull and I will appreciate it. I know that short circuit current from picture in attachment depends on impedance and reactance of Source MV, transformer example (10kV/0.4kV) and cables. So if I...
  32. Boltzman Oscillation

    What is the gain error for this opamp driven by a voltage

    Homework Statement The op amp has a near ideal level 1 model with G = 5000V/V, ri = inf, ro = 0 How would I obtain the feedback function? Homework Equations I know I have to find the feedback function which is: f = - (ΔV/Vin) The Attempt at a Solution I will first drive using the...
  33. A

    Engineering Find the time constant for this RC circuit, help please

    Homework Statement Homework EquationsThe Attempt at a Solution
  34. Lapse

    Engineering Finals Study Time A Two Source Circuit w/Inductor, Cap, and Resistor

    Homework Statement Homework Equations Z = √(XC2 + XL2) XL = 2πƒL XC = 1 / 2πƒC I = V/Z The Attempt at a Solution First off, thank you for all of the help this semester. I'm sure you'll be seeing questions from me in the spring also. Here is how I'm thinking about this problem: 1. Using the...
  35. R

    LRC Series Circuit Critical Damping

    Homework Statement Homework EquationsThe Attempt at a Solution My attempted solution is above and here https://imgur.com/8RmDMf8/ I'm confused as to the answers in the book being i and iii (I just don't see how i is included). If critical damping occurs at the value above, and if you go above...
  36. S

    Engineering Solving a Circuit with a Complex Source

    Homework Statement An image of the problem is attached. I need to solve for ic(t) and vc(t) by adding a complex source. Homework EquationsThe Attempt at a Solution I don’t know where to start here. I don’t understand the question, and I can’t find the information I need in my notes. Can...
  37. L

    How to Determine the Resistance R1 in a Mixed Circuit Analysis?

    Homework Statement The following circuit is given, and all voltage, current, resistance and power must be found for each resistor. I have found the following information: Vsrc = ? Isrc = .5A Rsrc = ? Psrc = ? V1 = ? I1 = .5A R1 = ? P1 = ? V2 = 2.5V I2 = .25A R2 = 10 P2 = .625W V3 =...
  38. Y

    How do you analyze this circuit

    This in not homework. I am playing with this circuit and I don't understand what is not right. Here are the circuits. a) I "built" an opamp out of U6, U7 and U8. I set the gain to 21 by R6/R3+1=20+1=21. The output is OUT1. But I get a little more gain than expected, like 22 or 23. b) I use...
  39. F

    Engineering Draw the equivalent circuit using only NAND gates

    Homework Statement For the circuit shown below , draw the equivalent NAND gates . Homework Equations - The Attempt at a Solution Could someone check my answer please ?
  40. H

    Open circuit voltage of an old battery

    Why the voltage of an exhausted battery, in open circuit state, is almost identical with that of new battery? The internal resistance of an exhausted battery is very large and so, the large amount of energy consumed by the source (for overcoming the electric filed in the battery) would waste in...
  41. sneakycooky

    Find the charge q(t) for an LC circuit

    Homework Statement An LC circuit consists of an 82 mH inductor and a 17 microfarad capacitor that initially carries a 180 microC charge. The switch is open for t < 0 and is then closed at t = 0. a. Find the frequency of the resulting oscillations. b. At t = 1 ms, find the charge on the...
  42. e0ne199

    Engineering Problems about Zin in complex circuit analysis

    1. Homework Statement the problem is my answer for question (a) is not the same as the answer provided by the question, i get 2.81 - j4.49 Ω while the answer demands 2.81 + j4.49 Ω Homework Equations simplifying the circuit, details can be seen below The Attempt at a Solution...
  43. Nikhil Rajagopalan

    Charging and Discharging of a capacitor in an LC circuit

    In an LC circuit, the capacitor that is initially charged to a finite value starts to discharge cross the inductor, initially the current increases and the inductor opposes it, but as the current is supplied against the back emf, due to the discharging of the capacitor, won't it reduce the value...
  44. Boltzman Oscillation

    Engineering Derive expressions for the voltage gain of this opamp circuit

    Homework Statement Derive the expressions for the voltage gain (Gv) of the following op amp: Homework Equations In = Ip = 0 Vp =VnThe Attempt at a Solution I can use KCL, and the fact that In and Ip are both 0, to derive the two equations, one from the top node and the other from the...
  45. Shivang kohlii

    Current through source in AC circuit with R & LC in parallel

    Homework Statement In the circuit diagram shown , Xc = 100 ohm , XL = 200 ohm , R = 100 ohm , the effective current through the source is ? Homework Equations Z= √( R^2 + ( XL - Xc)^2) Vrms = Irms/ ZThe Attempt at a Solution I tried to draw the phaser diagram and calculate the relation...
  46. archaic

    AC Circuit and Thevenin's theorem

    Homework Statement I'm asked to find the thevenin equivalent circuit, the load being ##R_1## ##e(t)=E_0\cos{(\omega t)}## ##R_1=1k\Omega \ R_2=R_3=1k\Omega## ##C=220nF \ f = 250Hz \ E_0=10V## Homework EquationsThe Attempt at a Solution ##Z_{th} = Z_{R_2}//(Z_c+Z_{R_3}) =...
  47. Lapse

    What is the Voltage on C1/C2 after the switch closes?

    Homework Statement Homework Equations Vf+(Vi-Vf)e-t/RC Tau = RC The Attempt at a Solution [/B] Normally, I would use the eq'n mentioned above to find Vr in an RC circuit. However, this second capacitor is throwing me off. Is there a new equation I should use? How do I think about this...
  48. Peter Alexander

    Engineering Computing resistance in given circuit with BJT

    Hi, before you proceed with reading this question, I would like you to know what I do not expect anyone to solve this task for me. I have a problem with a single step in the solution and I'm only asking you to help me with this one step. 1. Homework Statement Compute ##R_B## so that Q-point of...
  49. A

    How do I use full-bridge strain gauge circuit to measure F?

    Hey all, I am using a Wheatstone bridge with 4 strain gauges as resistors. I have a formula for the output voltage (Vout). My questions is how do I make it so instead of voltage I measure force? Do I simply apply a set max. force (let's say 140N), see what voltage I get (Vout,max) and then use...
  50. C

    Engineering Input Impedance of a MOSFET circuit

    Homework Statement (From Razavi's Design of Analog CMOS Integrated Circuits - Chapter 6) Homework EquationsThe Attempt at a Solution Not too sure about calculating the input impedance of this. Initially I thought that it would be the series combination of C1 and C2, since we are...
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