Ac circuit Definition and 199 Threads

Homework Statement Now suppose the power supply is 1200 V, and the motor is rated at 100 W at this higher voltage. If the wires have a resistance of 7.0 ohms, what is the voltage drop across the wires? The voltage at the motor? Homework Equations Power= Irms*Vrms V=IR The Attempt...

Homework Statement Given the load impedence is 18 + j15 ohms, what is the line current. Follow this link to see the circuit and the variables. http://www.flickr.com/photos/61312863@N07/5584165017/ Homework Equations Vab = Van*root[3] angle 30 degrees Iab = Vab/Z Ia = Iab*root[3] angle...

Homework Statement I'm struggling to figure out what vectors I use for my phasor diagram for an RLC series circuit. Homework Equations VC = 1/j\omegaC VL = j\omegaL VR = IZ The Attempt at a Solution I know how to add vectors, so that's not a problem, transfer my circuit from the time...

An AC circuit consists of 3 segments: a capacitor, then another capacitor which is in parallel with a resistor, and then finally another capacitor, these 3 segments being in series with each other. The formula which describes the charge Q(t) on the left hand side plate of the first capacitor...

http://imageschip.com/image-2CC0_4D720BE9.jpg In AC circuit when the voltage is zero the current is maximum... When it reaches to 90 then the current is zero... And same as for the other cycles till 360... Why the current is maximum when the voltage is zero and when the voltage is maximum the...

I am confused when it comes to this AC circuit problem. It is part e. The back of the book shows that V_R3 = 100 V. But as you see from my calculations, I get V_R1 = 20 V and V_R2 = 100 V. So shouldn't V_R3 = 0 V because the original voltage source for this AC circuit is 120 V, yet the book...

Homework Statement A non inductive resistor takes 8A at 100 volts. What inductance of a coil of negligible resistance must be connected in series in order that this load can be supplied from a 220 volt 60 Hz mains. Homework Equations Z^2 = R^2 + XL^2 R=V/I XL = 2pi(frequency)...

Homework Statement An induction motor load of 2000 kVA has power factor 0.80 lagging. Synchronous motors totaling 500 kVA are added an operated at a leading power factor. If the overall power factor is then 0.90 lagging, what is the power factor of the synchronous motors? Homework...

Homework Statement I am given a RLC circuit with a AC power source (e.g. signal generator), and i want to find the reactance of the capacitor. Given: R = 2200 Ohms, L = .025 H, C = (1 x 10-9) F, V0 = 5 V f = 3000 Hz Homework Equations edit: Sorry i wrote wrong formula.. here is...

capacitor question...(why does AC need a return path) say you have an ac power source (120 v) connected to a circuit which just has one parallel plate open air capacitor, with the plates separated by, say, 1 mm. you measure the current flowing through the circuit and you get some rms value...

Homework Statement [PLAIN]http://sphotos.ak.fbcdn.net/hphotos-ak-snc4/hs894.snc4/72731_10150110340044992_712009991_7710053_709779_n.jpg The circuit has a non-ideal inductor with parasitic R. v0(t) goes to coswt as the limit of w goes to zero. The output signal has a +15 degree phase...

Homework Statement I was able to find the solution to this problem but I don't understand where it comes from. A series RL circuit is connect to a 110-V ac source. If the voltage across the resistor is 85 V, find voltage across inductor. Homework Equations Not sure. The...

Homework Statement For which of the following AC circuits does impedance depend on frequency? A circuit with Check all that apply. a resistor and inductor. a resistor and capacitor. only a resistor. Homework Equations The Attempt at a Solution I think that for a capacitor...

Now this is not a homework question, just a practise question and my answer doesn't match. An AC source of 200 V rms supplies active power of 600 W and reactive power of 800 VAR. The rms current drawn from the source is ? (the answer is 3.75 while mine is 5) I did was squared and added the...

Homework Statement R=250 L=6 C=15microf e(t)=300sin(50pi t) Find Z, phase angle, lead/lag, emf(215ms) (got all of this right) Voltage across inductor, capacitor and resistor, also show that the sum of the voltage across the elements at 215ms is equal to total emf at 215ms. Homework Equations...

Homework Statement Fit P(w) to determine Q, and w_0, and R. You should put in Vrms as a known constant. Homework Equations P(\omega)={\frac{V_{rms}^{2}}{R(1+Q^2(\frac{\omega}{\omega_0}-\frac{\omega_0}{\omega})^2)} Q=\frac{\omega_0}{\Delta\omega} R=R_load+r The Attempt at a...

Homework Statement Given resistance of circuit 68 W, I(max) = .191 A, V(max) = 22.5, what is the average power of this circuit? Homework Equations P(avg) = I(avg)V(max) The Attempt at a Solution I took .191 and divided by sqrt(2) to get the rms current and multiplied by the max...

Homework Statement A Purely resistive resistive 100w, 110v lamp is to be supplied by an a.c. source of 230v r.m.s at 50Hz. what value of pure capacitance could be put in series to adjust the current flow to a suitable value? Homework Equations p=iv q=cv v=ir i know a number of other...

Getting powers from Ac Circuit Homework Statement Hi guys,, need help with the following question : The Attempt at a Solution OK, first things first ,, what does the question mean by saying ?? and I know that real power equal I^2 R for series & V^2/R for parallel but the problem it...

How do you express impedance in terms of w(omega), R, L and C knowing the circuit diagram. I understand that for R Z=R L Z=iLw C Z=-i/wC What is the effect of having components in parallel/series, could someone please give an example of a circuit and it's impedance expression...

I'm having a bit of trouble understanding how phasors/complex numbers are used to solve circuits which include capacitor, inductor and resistor components. Has anyone come across video lectures/youtube tutorials/websites that provide comprehensive solutions to a whole bunch of...

Homework Statement I have a couple of questions about one of my homework assignments any help would be greatly appreciated. 1. How do you find the Voltage drop of a Resistor in an AC Circuit is it similar to DC? V=IR The Resitor value is 68 ohms and there is an 80mH inductor in front of...

Hi there Im new to this site and i have noticed that you give advice to electronic questions. Presently I am studing electronics and on some of my course work i am having some difficulty in understanding some of the questions. such as, Q1 A conductor 300mm long moves at a uniform speed of...

Homework Statement Calculate the magnitude and sign of i12 which will flow through a capacitor of 10microfarads when: v12 = +50V, and decreasing at a rate of 104V/s Homework Equations Vab=Q/C The Attempt at a Solution No idea where to even begin with this question I am affraid. :(

I don't understand when you have an AC Circuit that has a coil, capacitor and resistance. What factor will the resonant frequency change when the frequency is tripled?

Was wondering if anyone can confirm that I am on the right track or not? I'm not sure whether Irms is meant to be a complex number not :/ Thanks in advance, otester Homework Statement A complex voltage v(t)=60sin(3wt)+15sin(3wt)+10sin(5wt) volts is applied to a coil of inductance 5mH and...

Assuming equal voltage, will it burn-out an AC light bulb if I put it on a DC circuit?

Homework Statement The voltage across and inductor reaches its maximum value 22ms before the current supplied by the generator reaches its maximum value. What is the lowest possible frequency at which the generator operates? Homework Equations I used the equation V=V_(max)sin(wt+90)...

Homework Statement A circuit contains only two of the three elements L,C ,R. When connected to a 120 V , 60 HZ ac generator, the current of 6.4 A lags the voltage by 30o. What are the two elements and their values? Homework Equations The Attempt at a...

Hi All, My name is Joaquim and I'm new in this forums. I am a Electronic Engineer student (1st Year). I have a question about a Thevenin equivalent circuit in AC. I need someone to tell me if I'm doing the right math in finding the thevenin equivalent (AB point): Please see the...

Homework Statement It's a simple AC circuit with a 100ohm resistor and a 10mH inductor connected in series. The voltage is given as a function rather than a quantity: V = 20sin (5000t). Problem asks to find the peak current in the circuit. Homework Equations i = integral (V/L)dt Z = sqrt...

Homework Statement http://img159.imageshack.us/img159/1867/es100wi8.th.png http://g.imageshack.us/thpix.php a) Write an expression for V1 and V2 both in time domain and phasor domain (Solved) b) Write an expression for the current I both in time domain and phasor domain (Solved) c) Calculate...

Im doing mesh analysis on an AC circuit only problem is i don't know how to handle the dependant voltage source. My circuit: http://img139.imageshack.us/my.php?image=accircuitrx0.jpg I think I am supposed to just assign a value for Vo but I am not sure. Is it possible to work out what Vo...

Homework Statement Find the impedance of the circuit (R and L in series, and then C in parallel with them). A circuit is said to be in resonance if Z is real; find ω in terms of R, L, and C at resonance. Here is the circuit: http://img382.imageshack.us/my.php?image=g...ccircuitgf5.png...

Homework Statement There is a circuit formed by a capacitor and a resistor with an AC source of 212V. It is known that the currentr that goes through the circuit is 0.5A, with a phase angle of pi/8 rad in relationship with the tension and that the power consumed by the circuit is 50W. What...

Homework Statement In a domestic house, the voltage on the supply is 230V at angle 0 degrees. A number of household appliances are connected to the single phase supply causing a current of 20A at a power factor of 0.75 lagging to flow from the supply a) What power is being consumed by the...

At resonnance, the phase angle in an a.c circuit is ?pls need an answer. 2. the magnetic force on a charged particle moving with velocity v is ? 3. The current through a resistor in a.c circuit is given as 2 sin wt. Determine the d.c equivalent of the current? 4. What is the angle of dip at...

Hello. When a capacitor is connected in a circuit with an ac supply, a current flows in the circuit. fine. The problem is, does a pd develops across that capacitor, and does it store energy. As in does it "Charge" up?

Hello, suppose we have a sinusoidal AC source connected to only a pure inductor of self inductance L ( no resistance at all ) ..then emf induced in the inductor is L * dI/dt and is equal and opposite to the applied emf. but if the induced emf opposes the applied emf , then how can there be a...

Homework Statement A resistor with resistance R and a capacitor with capacitance C are connected in series to an AC voltage source. The time-dependent voltage across the capacitor is given by V_c(t) = V_c_0 sin(wt). A) What is the amplitude I_0 of the total current I(t) in the circuit? B...

A 60 Hz power source with a peak voltage of 12.0 V is connected to a resistor. At a particular instant the voltage across the resistor is 10.0 V and decreasing. What is the voltage 1.5ms later. I tried using the equation v= V cos(2 pi ft) v= 12.0V cos(2pi (60Hz)(1.5 X 10^-3s)) v= 10.13...

i have no idea what it is.. Please help An AC circuit contains only an inductor. Which of the following is correct. a. the current lags the voltage by 90 degrees b. the current lags the voltage by 180 degress. c. the voltage lags the current by 180 degrees d. the current and voltage are in...

Ok I've been given a problem that I've got stuck on, I was wondering if anyone here could help. Q: v(t) = 100 sin(200t+20^) i(t) = 10 sin(200t-10^) Express voltage and current as phasors, and calculate the average power being supplied. (I've used ^ to denote degrees) The phasors part...

Hello everyone. This should be a fairly simple question to answer because I should really already know. Anyway, I was just wondering how exactly a battery is recharged in an AC circuit. In particular, I was looking at an electric car's rechargable battery. I know when you plug the car in the...

Homework Statement The voltmeter in the circuit sketched in the link below reads 100 volts. What currents would ammeters indicate for I1, I2, and I3? What is the phase relation between the applied voltage and I3? http://i43.photobucket.com/albums/e394/risendemonx/prob3pic.jpg...

Homework Statement Imagine a simple AC circuit with a voltage source and an inductor: Determine the current going through the circuit. Homework Equations voltage of the source: v = V_m\sin{\omega}t induced emf in the inductor: e = L\frac{di}{dt} The Attempt at a Solution By...

Explain why a pure capacitor or a pure inductor does not consume electrical energy, while a pure resistor does. Illustrate your answer using waveform diagrams. I need some wave diagrams for this. I have no idea what the waves look like

Physics Help?? In an AC circuit write down the voltage (V) versus current (I) relationships for a resistor, a capacitor and an inductor in terms of agnular frequency (w) and the resistance (R), Capacitance (C) and inductance (L), respectively. From this define capacitive reactance and inductive...

Consider an AC source with series elements (resistor,inductor, capacitor). In order to determine information from the circuit it is useful to consider impedance. So here's the question, total impedance is a complex number, and that is because the impedance of the cap and inductor are imaginary...