Ac circuits Definition and 75 Threads

In circuit complexity, AC is a complexity class hierarchy. Each class, ACi, consists of the languages recognized by Boolean circuits with depth



O
(

log

i



n
)


{\displaystyle O(\log ^{i}n)}
and a polynomial number of unlimited fan-in AND and OR gates.
The name "AC" was chosen by analogy to NC, with the "A" in the name standing for "alternating" and referring both to the alternation between the AND and OR gates in the circuits and to alternating Turing machines.The smallest AC class is AC0, consisting of constant-depth unlimited fan-in circuits.
The total hierarchy of AC classes is defined as






AC


=



i

0





AC



i




{\displaystyle {\mbox{AC}}=\bigcup _{i\geq 0}{\mbox{AC}}^{i}}

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  1. S

    Engineering AC Circuits: Phasors/Polar to rectangular transformation

    40<50degrees + 20<-30 degrees, I get how to convert to rectangular, I got 43.03 + j20.64, but converting it back to polar... how exactly do you do so? The answer is 47.72<25.63degrees... my book doesn't explain it. Also with (2+j4)(3-j5)... how exactly do you tackle this sort of...
  2. A

    The Skin Effect in AC Circuits

    In DC circuits the charge carriers move uniformly through the entire cross sectional area of the wire. In AC circuits the current is constrained to travel in a thin "skin" just below the surface of the wire, effectively reducing the cross-sectional area of the wire. The effect becomes more...
  3. C

    Electromagnetic Induction in AC circuits

    A 9.7 Ω resistor, a 10.8 µF capacitor, and a 27.9 mH inductor are connected in series with a 120 V (rms) source with variable frequency. (a) At what frequency will the current be maximum? Hz (b) Find the maximum rms current. A (c) Suppose you now replace the 10.8 µF...
  4. Q

    Why does OHMs law not work on AC circuits?

    can someone please explain to me physically how is it that when i have an AC source and i measure Voltage on a resistor its the same with and without the resistor and when i have a DC source and i measure Voltage again on the resistor and now there's a different reading its like ohm law...
  5. H

    What Is the Peak Voltage Across the Capacitor?

    Homework Statement A coil is connected to a 60 Hz ac generator with a peak emf equal to 80 V. At this frequency the coil has an impedance of 14 and a reactance of 12 . a.) What is the peak current in the coil? answer-5.71 Amps b.)What is the phase angle between the current and the...
  6. U

    Why Does Adding a Choke Dim an Electric Lamp in an AC Circuit?

    A)) A choke boil placed in series with an electric lamp in an AC circuit causes the lamp to become dim. Why? B)) A variable capacitor "added" in this circuit maybe adjusted until the lamp glows with normal brilliance. Explain how this is possible ATTEMPT: If V is the voltage of alternating...
  7. U

    Inductive and Capacitive Reactances - AC circuits

    Question: If we increase the driving frequency in a circuit with a purely capacitive load, do (A) amplitude Vc and (B) amplitude Ic increase, decrease or remain the same? If instead the circuit has a purely inductive load, do (C) amplitude V L and (D) amplitude I L increase, decrease or remain...
  8. O

    AC Circuits II: AC Power Generator

    Homework Statement A An AC generator supplies an rms voltage of 110 V at 60.0 Hz. It is connected in series with a 0.300 H inductor, a 5.80 μF capacitor and a 236 Ω resistor. What is the impedance of the circuit? B What is the rms current through the resistor? C What is the average power...
  9. S

    AC Circuit Resonance Angular Frequency Calculation

    Homework Statement In an L-R-C series circuit, L = 0.270 H and C = 3.80 µF. The voltage amplitude of the source is 120 V. (a) What is the resonance angular frequency of the circuit? Homework Equations Xc = 1/(wC) XL = wL w=angular frequency The Attempt at a Solution...
  10. I

    Engineering Magnetically coupled inductors an AC circuits

    Homework Statement I've actually uploaded the question. When solving problems with magnetically coupled inductors I like to add dependent sources so that I can keep everything straight. My question is when I add the dependent sources does there need to be a specific polarity to them. With...
  11. C

    Engineering AC Circuits Help: Get Answers & Solutions

    http://img12.imageshack.us/img12/5694/figure1.bmp Any help/explanations would be greatly appreciated.
  12. K

    How AC Circuits Work: Explained for Beginners

    This is a pitifully simplistic interrogatory, but here goes. Is this roughly how an AC circuit works?: An AC generator supplies an electron flow to start the circuit. These electrons then flow down a single wire to say a household fusebox/breaker. From there they flow to a wall plug and then...
  13. J

    What will be the voltage across the resistor in an AC circuit?

    Homework Statement Connecting a 250 ohm resistor, 1.2 mH inductor, and 1.8 micro F capacitor in series across a 120 V, 60 Hz peak source, what will the voltage be for the resistor?Homework Equations 1) I_peak = V_app peak / Z 2) V_R = I_peak * R ? The Attempt at a Solution I used equation 1)...
  14. R

    Engineering Questions regarding AC circuits

    Suppose that we have a simple system like one illustrated in attachment. If we need to find complex admittance of that system,we can write: \underline{Y}=G+jB=\frac{1}{\underline{Z}}=\frac{1...
  15. R

    How Can AC Circuits Be Analyzed Using Ammeters and Voltmeters?

    Homework Statement In circuit given in attachment,find the value which is showed on ammeter A,if voltmeter is showing 50\;V. Values are R=R_2=X_L=X_C=10\;\Omega and R_1=5\;\Omega. The Attempt at a Solution First I calculate current thought branch with R_2 and X_C...
  16. R

    A variety of questions regarding AC circuits

    Homework Statement In this circuit (In attachment.) find the value which is showed on ammeter A,if voltmeter is showing 50\;V. Values are R=R_2=X_L=X_C=10\;\Omega and R_1=5\;\Omega The Attempt at a Solution First I calculate current thought branch with R_2 and X_C...
  17. I

    Do AC Circuits Combine Coherently at 60Hz?

    Homework Statement my question is when you connect let's say many ac circuits into one circuit and the cycle is 60Hz. Do the cycles stay coherent to one another or do the pulses of the alternating current get mixed once they all combine into one circuit. Homework Equations The...
  18. C

    Why Did They Add 2π When Shifting AC Circuits?

    Hi everyone, I ran into the following little problem: Homework Statement Given v=40 cos(100*pi*t + pi/3), the question is: what is the minimum number of millisec that the function must be shifted to the left if the expression for v is 40 cos(100*pi*t) Homework Equations The...
  19. K

    AC circuits and Kirchoff's laws

    I was trying to solve an exercise. We are given an AC circuit (see attachment). We had to find the current trough the resistor, the inductor and the capacitor. This can be solved using the impedance: The voltage by the source is sinusoidal: V=V0*sin(w*t)=(complex) V0*exp(j*w*t) The total...
  20. S

    Understanding Resonance in AC Circuits: Exploring its Purpose and Applications

    Hi Guys! well can u explain me the term RESONANCE in AC Circuits. For what purpose it is used. How to use it. Can u recommend me any website from which i can get the right information and knowledge about resonance. Thanks in advance
  21. O

    How Does Ohm's Law Apply in AC Circuits and Oscilloscope Measurements?

    Ohm's law and AC circuits/ Biots / Oscilliscope hey wasssup... i'm doing a practice final and need some help ... It's askin which is true (1) Ohm's Law is true for all materials; (2) Resistance may depend on temperature (3) REsistance may depend on current (4) Ohm's law is...
  22. E

    AC Circuits: Signal Speed & Wavelength Calculation

    If an AC circuit has a certain frequency of oscillation, let's say undamped, i.e. first order. Then there is a way to figure out the wavelength and therefore speed of the signal? Does that mean that signal does not travel at speed of light all the time, but can potentially? Thanks in advance.
  23. denian

    How Do AC Circuits in Capacitors Behave with Increasing Frequency?

    there is one question i need someone to help me to check and another question that i need someone to help with. an alternationg voltage, V = Vosin (omega)(t) is applied across a pure capacitor of capacitance C. derive an expression for the capacitive reactance. i do it this way...
  24. A

    Software to help learn about AC circuits

    I'm a physics student studying AC circuits at university at the moment. To help in my understanding, I'm looking for an application which allows me to construct a circuit and simulate it working, and make measurements. Something which covered basic LRC circuits would be a start. I use Mac OS...
  25. A

    AC circuits with resistor/inductor/capacitor

    Hi folks, I am unable to answer the following questions. I know what the answers are (5 - b, 10 - b, 12 - c), but I do not know how those answers are explained. I am also unable to find any relationships in my textbook that explain the relationships expressed in these questions: 5. As...
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