Ac circuit Definition and 199 Threads

Homework Statement Homework Equations The Attempt at a Solution The text in the black box looks wrong to me. The method below is how I would do it. Why is it wrong? $$To\quad maximize\quad power,\quad \overrightarrow { Z_{ L } } =\overrightarrow { { { Z }_{ th } }^{ * } } \\ \\...

Here I have a problem I am dealing with. I answered the question and have it shown on the picture but I would like a double check on it as I think I am getting wrong values. The circuit is shown at the top of the page. If you can't see the values are 10 ohms for the resistor, 3.2 mF for the...

Homework Statement For the circuit in question1above: R=(3.74x10^2) (Ω), C=(3.8700x10^-7) (F), f=(4.610x10^3) (Hz) and the peak amplitude of the voltage of the source (ES)=(6.185x10^1) (V). Calculate the instantaneous value of the voltage across the capacitor at t=(4.110x10^-5) (s) after the...

I am half way through my Electrical Engineering program and have only just started to learn about AC circuits and inductive loads but I did a little reading and went off to try a simple project on my on. A company I work for wanted a switch to turn off their large refrigerator for certain...

Homework Statement 1. A 5.0 H inductor is connected to a 120 V rms, 60 Hz ac power supply. Periodically, the energy stored in the inductor reaches a maximum value. What is this maximum value? A) 0.010 J B) 0.020 J C) 0.40 J D) 0.80 J E) 10.0 J 2. A standing wave on a string is...

The circuit and questions are attached. Homework Statement First: Calculate the complex impedance of the circuit. Second:Limiting cases Third:Imax Lastly: Phase Homework Equations The Attempt at a Solution I've never had any ac circuits and the DC circuits I did before transferring were...

Homework Statement Homework Equations impedance equations for capacitors and inductors The Attempt at a Solution I thought something like that might do and then just do a matrix and solve for Va, but I am having second thoughts seems like I am over doing it.

Homework Statement Use the supernode technique to find I0 in the circuit Homework Equations nodal analysis, AC analysis The Attempt at a Solution Taking the left essential node as V1 and the right essential node as V2, V1 + 12V = V2 and -V1/(1-1j)Ω +...

Homework Statement Two nodes in a network are connected by a line with an impedance of 0.5 + 1.2j Ω. The voltage at the sending end is 33KV and at the receiving end is 32.5 KV with a lag of 1.5° compared to the sending end.. Calculate the current in the line and the real and reactive power...

Homework Statement If R1 = 2 Ω, X1 = 1 Ω, R2 = 2 Ω, and X2 = -2 Ω , the equivalent impedance Zeq (in ohms) at terminals a and b is: (the circuit diagram is attached to this post) a. 3 + j 0 b. 3 + j 2 c. 3 - j 2 d. 0 - j 2 e. 0 + j 2 The answer is a. I have no idea how to...

I'm trying to use single ac frequency analysis to measure voltage, current, impedance and phases stuff... But the current result displayed seem like decreased by 100 times?? this is my multisim file https://www.filesanywhere.com/fs/v.aspx?v=8b6a6b8e5c67757ab298

CAN Current pass Through INDUCTOR? how the AC circuit is completed when Inductor is in it as no AC pass through it?

I'm looking at an AC circuit. There is a voltage source, a resistor, an inductor, then another voltage source. One loop. I am supposed to find the power in each element and tell weather it is absorbing or delivering. I think I remember that when a current goes into the negative terminal of a...

Homework Statement In the circuit shown, a load having an impedance of 39 + j26Ω is fed from a voltage source through a line having an impedance of 1 + j4Ω. The rms value of the source voltage is 250V. a) Calculate the load current IL and voltage VL b) Calculate the average and reactive...

Homework Statement Use source transformation to find the Thevenin equivalent circuit with respect to terminals, a, b. Homework Equations Voltage Division: (V in)*(R1/R1+R2) Thevenin / Norton / source transformation procedures RTh = RNo VTh = INo*RNo Polar...

How does one go about triggering a switch (i.e. relay) via a resistive load in an AC circuit? For instance, if I have an AC relay (high impedance) and put the coil in series with the resistive load, it won't work: the resistive load will stop working. How does one go about triggering a relay...

Homework Statement For the circuit shown, what value of ZL results in maximum average power transfer to ZL? What is the maximum power in milliwatts?Homework Equations P max = (VTh)2/4RL Thevenin, Norton procedures, voltage division, current division, etc etc The Attempt at a Solution This...

Homework Statement For the circuit below, assume the source phase angle is 0° Write the differential equation which would allow you to find the voltage response across resistor R2. Using the General Solution for the solution of such a differential equation write the complete...

Homework Statement If an average power of 500W is dissipated in the 20Ω resistor, find Vrms, I S RMS, the power factor seen by the source, and the magnitude of VS (Based on circuit in attached diagram) Homework Equations Pave= Irms*Vrms*pf*\frac{1}{2} Imaginary number referred to as...

Not sure if this is in the right category because circuits are more of an electrical engineering-related area, but this is part of an assignment for a standard second semester calculus-based physics course (i.e. E&M), so I'll leave it here for now. Feel free to move it to another category if it...

When you're asked to find I(t) in an AC circuit, what form does I(t) need to be in? I remember from a long time ago that when the '(t)' is included you have to have it in a specific form.

1. Homework Statement . A wire coil has both resistance and inductance, and is connected in series to an AC power supply with 80Hz and 180V, drawing 0.4A current and 18W power. The circuit consists of a single loop. 1. Calculate the inductance and resistance of coil 2. Plot vector of...

From the 1st screenshot part ii of the question: My working: Vm x √2 = 28.284 x √2 = 40v (Answer Correct) I would like to ask a question from the 2nd screenshot. "Determine the effective (r.m.s) value of this voltage waveform over one complete cycle. I don't know how to solve this...

Homework Statement The question is: The given answer is: Homework Equations The Attempt at a Solution I already got the "correct" answers. My question is, I used Vrms voltage and Irms current to solve the nodal analysis. Would it be incorrect to use Vpeak and Ipeam to solve the circuit...

A 20.0-mH inductor is connected to a standard electrical outlet (ΔVrms= 120 V; f = 60.0 Hz). Determine the energy stored in the inductor at t = (1/180) s, assuming that this energy is zero at t = 0. Now when i tried to solve it, this is what i did: ω = 2∏ f = 2∏(60.0/s) = 377 rad/s XL =...

Homework Statement A circuit is constructed with an AC generator, a resistor, capacitor and inductor as shown. The generator voltage varies in time as ε = Va - Vb = m*sin(ωt), where m = 24.0 V and ω = 187.0 radians/second. At this frequency,the circuit is in resonance with the maximum value...

In an AC circuit, the average power dissipated is given by P=VIcos(\phi). Does that mean that in a highly inductive, or highly capacitave, circuit where \phi approaches \pm \pi/2 , the power can be made arbitrarily small? Even if a resistor were present? Does that mean it wouldn't heat up at all?

Recently, I've been studying AC circuits and have developed a couple questions. I think I worked out an answer to the first, but I don't know about the second. First, since light bulbs in houses are powered by AC current, why do we not see them flicker? Assuming they obey Ohm's law, the...

I need to perform mesh analysis using complex numbers on an AC circuit. My issue, is I don't understand how to do this. The circuit contains only one voltage source, where we have only been taught how to perform a mesh analysis on a circuit that contains 2 voltage sources. Can someone show me...

Hi, I'm investigating maximum power transfer in a AC circuit. I understand that for maximum power transfer the reactance both cancel each other out and the value of the source resistance and load resistance have to be equal. I have also found some formulas to prove this. what i would like...

I've been given the following problem (attached), not sure how to tackle this one, do I use mesh/node analysis and super node analysis, or can I find the v in the loop with the dependant voltage source then use that as the supply to the second and third loops? Not sure, any help would be...

How to draw a phasor ? Homework Statement Two alternating currents are applied out of phase with each other. One is 4 volts and the other is 3 volts 27° out of phase. These can be written as (4, 0°) and (3, 27°) Homework Equations a)draw both phasors b)draw the combined phasor...

Homework Statement Just before reading, i am posting this as this question seemed way to easy to solve in my assignment, problems aren't usually this easy ! haha. I need to find V0, i originally just found the voltage at that node using KCL which was straight forward, but in my lecture notes...

Homework Statement A radio tuner built by connecting an L=0.58mH inductor and variable capacitor in series with an antenna. The driving voltage is provided by the radiowaves that pass through the antenna, and the total internal resistance of the circuit is R=2.6Ohms. The variable capacitor is...

So I've been trying to figure out what I'm doing wrong regarding a theoretical aspect of this lab. I've used both ideal analysis and experimental analysis and can't figure out if I'm doing this right. The circuit is shown produced in Multisim below: The function generator produces a...

Hey guys, Just need some help with this question, It asks for the answers to be in circuit parameters: http://tinypic.com/r/k0k2ed/5 For some reason I don't think my answers are correct as I'm finding it hard to make sense of my answers to the questions. a)Find the voltage Vab (magnitude and...

Homework Statement A circuit contains two elements, but it is not known if they are L, R or C. The current in this circuit when connected to a 1.20×101 V, 60.0 Hz source is 4.70 A and lags the voltage by 4.20×101 degrees. a) What are the two elements? (Answer A,B or C) CL CR LR Homework...

I know that in an AC circuit at the steady state a capacitor behaves like a short and inductor behaves like an open. Since the inductor is open wouldn't that just mean the answer is 0?

"why are inductors preferred over resistors in reducing current in an AC circuit?" The quoted question from a recent exam has caused a little dilemma regarding it's interpretation and answer. 1) what does 'reduce' refer to? 2) inductors are preferred as the impedence is dependent on the...

I have taken apart a speaker set which uses a transformer to transform the 230-240v mains it receives into 9v AC 1A. I want to connect this circuit to a 9v battery. Nothing complicated-the standard Duracell one. Does anyone have any advice/comments on whether this will work or not? Regards...

how to find power factor of the load, the three voltmeter readings are V1=220v,V2=122v,V3=136v

Hi, I am currently struggling with this AC question that is required for my first year electrical engineering coursework. I know sort of how to go about it all, but am having a really difficult time implementing the correct calculations. Any help would be appreciated! Context You are given a...

Voltage V(t)=V1 Re{eiwt} produces a current I(t)=I1 Re{e(iwt+θ). Determine I1 and θ. The circuit is AC so do I treat it the same as an SHM question? Is π/2? And what do I need to do to find I1? I don't know where to start.

If you have an alternating voltage source in series with one inductor what happens? The book has a graph of the alternating voltage source and the current through the inductor. What I don't understand is how there is current in the inductor at t=0. If you look at how I solved the problem I...

Homework Statement I need help with determining the current through the 1Ω resistor. http://img403.imageshack.us/img403/5422/acex22.jpg The trouble I have is that the voltage sources are phased as given in picture, and I got stuck on how to deal with these phases when calculating the...

Hello guys! This is not quite a homework, but anyway. Homework Statement I'm trying to figure out some details about the circuit below. The circuit contains two voltage sources. V1 is 5V 100Hz AC source, V2 is 15V DC source. I know I can analyze this circuit simply treating it as if there...

Homework Statement A 200? resistor is connected in series with an AC generator that produces a peak voltage of 10.0V. What is the peak current through the resistor if the frequency of the source is (a) 100Hz and (b) 100kHz Homework Equations V=IR The Attempt at a Solution I just...

In an a.c.circuit containing only inductance, for example, it is said that the current is lagging behind emf by 90 degree. We can understand this that when the emf is zero,the current is at its negative maximum and when the emf reaches its positive maximum, the current becomes zero and so on...

Ok guys this one is straight out of a textbook, (Tooley, M. and Dingle, L. (2008) Higher National Engineering, 2nd ed. Oxford: Elsevier, p.353.) Homework Statement v=50sin(\omega t)+10sin(3\omega t + \pi /2) i=3.54sin(\omega t + \pi /4) + 0.316sin(3\omega t +0.321)Homework Equations...

Homework Statement An ac voltage source is connected in series with a 1 uF capacitor and a 750 ohm resistor. The amplitude of the voltage source is measured to be 4V rms while the voltages across the resistor and across the capacitor are 3V rms and 2.7V rms respectively. Determine the...