Ac Definition and 1000 Threads

Is there a simple way to "make" static electricity from an AC outlet? Looking for a way to make my hair stand (what is left of it) on its end for an experiment. Thanks for your comments in advance.

What will happen in a ferrofluid in an elastic cylindrical tank when subjected to high voltage alternating current? Is it will expand and then back to its normal dimension periodically because of repulsion? The diagram on the attachment is the set-up, all answer will be appreciated. Thanks

Hello, I want to design an AC voltage indicator. So i designed the circuit attached, but now i am trying to calculate the value of the resistor R1. I have the following problem: 1- The voltage should be given at the terminals of the optocoupler. 2- The minimum current that should flow...

Often I'm reading on other sites that if a 2 pole 3600RPm (synchronous speed) motor were connected so that the ratio would lower the speed to the same as a 4 pole (2X) and so on with 6 pole (3x) the output HP will remain the same. However the larger the number of poles the larger the motor and...

I am new to engineering so i might not understand the concept well , but i want an ac source to provide current only in one way , so i can connect them in parallel. I have 2 AC sources one with a 100 V output and one with a 120 V output , i need to connect them in parallel so i can get a 220 V...

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...

What happens to the power dissipated in a resistor when the voltage across it is changed?

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.

I'm using a LM[Three-One-Seven] to regulate dc voltage output from mains power(240V ac). For PSPICE simulation, I was instructed to use an ideal OpAmp and Darlington BJT to model the IC in PSPICE. I came up with the following model, which satisfies the equation Vo=Vref(1 + RL/RH), where Vref =...

Homework Statement hello everyone I'm a little confused with the whole 3- phase system. for example: I tried solving using differenet methods we were taught, but every way i try i get a different result. For example: 1) I thought that the wattmeter will measure the Real Power of a...

I have checked How Stuff Work, About.com, Ask.com, Google and even asked an electrical engineer and found no satisfying answer to the following questions: For household AC current, why do we need 2 live, a neutral and a ground 4-wire connection? We get 3 wires from the street transformer where...

A trapezoid ABCD ,AB//CD ,AD=BC Prove : $AC^2=AD^2+(AB).(CD)$

I am sure this is a set of naieve question first of all. However i'd appreciate someone taking the time to enlighten me, as my mind is boggled by this and has been for some days now. I have watched numerous videos on the subject of electricity but am still somewhat confused. My issue is taking...

I have a torque meter using a full-bridge Wheatstone bridge (all legs are strain gauges). The bridge has some non-zero, unknown offset (it's old). I would like to strip this offset out prior to signal amplification. My theory is, under DC conditions, the offset exists, which mucks up the...

Homework Statement Determine the T-network equivalent of the ∏ (Pi) network shown in the Figure? Homework Equations I started working on this question and don't know if I am heading in the right direction. The impedances of the T network (Z1, Z2, Z3) can be found from the impedances of the...

Hello again, I am having a bit of trouble understanding superimposed voltage. Here is the problem: A sinusoidal AC voltage source is in series with a DC source. Effectively, the two voltages are superimposed. Draw the total voltage across RL. Determine the maximum current through RL and the...

Hi all, I would like to ask for suggestions on how to measure the frequency from my main supply which is 240V? As i know the frequency varies very little, hence i would like to measure it as accurate as possible. The reason for this is because I'm doing a smart meter project with Arduino...

I really don't know much about circuit design, but I have built a device and it requires a LED indicator when power is applied to the load. I also need a very low parts count. The Problem. As I have designed it the LED glows ever so dimly when ac voltage is removed and when power is...

Hello, I have a question, How can I calculate the working time for the following scenario: I have 12V 7.2AH LEAD ACID SLA DEEP CYCLE BATTERY Then I used DC 12V to AC 220V Power Inverter USB 1000W to give me AC I connected one 100w lamp .. For how long it will work ? how can I...

Hello people! I've been absent from this forum for quite a while. But now I return with questions regarding a little project I have to do. So basically I have to make a AC and DC power supply. I need 24 V AC output and 0-30 V DC power supply. I have a transformer(I think its 220V/24V)...

Assume that $a, b, c, d$ are positive integers and $\dfrac{a}{c}=\dfrac{b}{d}=\dfrac{3}{4}$, and \sqrt{a^2+c^2}-\sqrt{b^2+d^2}=15, find $ac+bd-ad-bc$.

Hello everyone. I have just bought myself a multimeter just for fun. So I've been going around testing voltages and current of things... I have a few questions, and more to surely come later... 1st. When they say Direct Current flows "in one direction" and Alternating Current flows in "both...

Hello, This is my first post; so first of all, let me thank all of you for starting and running such a good forum that provides lot of help and insight into various engineering problems. As to my brief introduction, I am an IT professional with educational background in (Mechanical)...

Hey all, Just a question concerning the image I have provided. If I have an offset of 0.1 mV at the non inverting input, how exactly does coupling take effect in this set up? If I input an ac signal, it will pass through the cap, but will the op-amp not still experience the offset voltage?

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...

Is there a formula that shows the relationship between AC power and DC power? Something on the lines of, for example: Power of AC ... = Power of DC ... ? Thank you.

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...

On a hot day the AC in my car starts working immediately pumping cool air, on a cold day I have to wait till the cooling system heats up before I get warm air. It would be perfectly possible (with the aid of a couple of solenoid valves) for the AC unit to run as a heat pump providing immediate...

The unit consists of a single, long rectangular chamber. On the inside is a moving wall. On one side of the wall is a vacuum, and the other side is room-temperature air. The moving wall starts much closer to the side with the air and moves slowly in the vacuum direction. As this happens, air...

We have ~78 underground pull boxes (12ft by 12ft) scattered around our 700m by 1500m yard that are passing 12kV cables through underground ductwork.(i.e. pipes) See figure attached for detailed drawing of layout including pull boxes, station service transformers and control buildings...

Hi, I work in the construction industry. I have a homeowner that would like to protect herself from electromagentic field (EMF) exposure. (She fears cancer from EMF's.) The airconditioning unit in their AC room produces a large electromagnetic field. She wants to prevent this field from...

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?

With large wind turbines which have AC generators why do they convert from AC to DC and then back to AC before connecting to the grid, why not just connect straight from generator to the grid without converting? Very confused please can someone explain!

So far i have learn Vrms, Vdc and Vac, and this is what i understand Vrms is the power of the voltage, Vdc is the average voltage. And what is Vac actually? The sine wave? another word for R.M.S, or it is the value of AC voltmeter can measured out, I am not sure where i find this...

I've an emergency fan with an AC/DC button on it, but its manual doesn't say on which setting it should be charged. I've tried charging on both settings, and it can be charged either way. On the back of the fan it reads: "AC 220/240 50/60Hz 19w" The fan's box only says: "DC...

OK... so my understanding is that a DC generator under no load generates high voltages without any current, but does the same hold true for an AC alternator? What happens with current when the RPMs of the alternator exceed what is necessary for the current requirements?

Hello physics friends! I have a question about AC current I hope you can help me understand. So I know that putting AC through a transformer will raise or lower the voltage, but because power has to be kept constant, the current changes in the opposite direction. But according to Ohm's law...

Hi All, I am looking for a sensing circuit, which can sense voltage signal between AC (85-265Vac) and DC (20-28VDC). Any idea how to design this circuit? Here is the main project: - looking for power supply circuit with Single Input terminal for AC as well as DC voltages. I would like...

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...

"when we apply AC to an inductor (pure inductance), the current will lag the applied voltage by 90 degrees. " how this happens? why current lags applied voltage by 90 degrees? :confused:

AC Electric Neutral Current "Flow" Hi everyone Can someone point me in the right direction here please. Happy to do the digging, but so far I can't find anything that helps! In an AC alternating-current electrical circuit, the Neutral wire is ultimately connected to "mother earth" / "big...

Hey guys! Novice physics scholar here who's studying electronics on his downtime. I have some questions concerning AC and DC. If you guys could answer them (simplistically please, I still have a lot to learn :P) I'd really appreciate it. I'm reading here that 'AC costs less to generate then...

Hello dear PF-members! :shy: I'm looking for some appropriate formula which could be utilized to calculate the magnetic field density in a straight high voltage AC mere cable. If you're more into the details of why I may ask this - I'm working with the railway maintenance and got interested in...

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...

Hi guys! So I've just recently started learning about phase relationships for inductors and capacitors in an AC circuit. But a few things keep bugging me: Say we have a RL circuit (a resistor + inductor + voltage source all in SERIES), and we we're asked to draw a phasor diagram for the...

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...

Hello, Is it possible to run heating and elements and other devices with DC supply? I have turned on Nickel-Chromium Heating wires with AC but is it okay to use it with DC supply? What's the main practical difference between AC & DC, as long as the voltage and current of supply is...

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...