Ac Definition and 1000 Threads

i am not sure if this is considered electrodynamics under classical forum but oh well, here goes i was reading wiki about p-n diodes and its that for reverse bias diode, because of the anode attracting the holes WITH the cathode attracting the electrons, the depletion zone widens and causes...

Hello All, I am interested in constructing a small Hofmann apparatus for electrolysis (as a hobby), like this kind: http://en.wikipedia.org/wiki/Hofmann_voltameter" I am confronted with the choice of either using a bunch of 9V batteries, or some kind of AC/DC rectifier. As I am a...

I just wonder if the readers here realize a couple of things. 1. Basic Ohm's law is different than the Laboratory Ohm's law. 2. If a DC voltage is applied to a resister, an AC voltage is always generated across the resister. I hate to use 'always' but as far as I know it is this way...

Please remember that I'm not a science or physics student, so please explain as simply as you can. Thanks. In the case of DC current electrons flow from a negative terminal to a positive. A negative terminal is full of electrons and the positive is electron deficient. I'm trying to understand...

Hello everyone, I have a few microwave caps rated at 2100 Volts AC and was wondering about their DC rating. I've heard that the DC rating of AC caps is usually 3-5 times the AC rating which seems to make sense but I'm not absolutely sure... If someone could please confirm or deny this I'd be...

Homework Statement An AC generator in an LRC circuit produces a voltage V(t) = 1.414sin(wt) = 1.414sin(1000t) The values of inductance, capacitance, and resistance are shown in the diagram. Recall the w = 2pi*f. i made a picture of the diagram...

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...

Hey guys I just need some help on something The question is: A motor attached to a 120 V/60 Hz power line draws an 8.50 A current. Its average energy dissipation is 800 W. I got the first 3 parts of this question correct... 1. What is the power factor ans = .784 2. What...

Im using the 7809 IC to get 9v regulated dc supply. However, I'm also getting about 14v ac in the output as well. I've tried putting a notch filter tuned to 60hz to remove the ac voltage, but its still there. I'm using this power supply to power tl072 op amps and I'm worried that the ac voltage...

Homework Statement An AC generator, originally designed to provide a peak output of +/- 155V at frequency 60Hz, is required to provide a peak output of +/- 340V at 50Hz. If the generator is connected to a transformer with 200 loops in its primary coil, how many loops should there be in the...

Can anyone help me convert 12v DC to AC for the purpose of measuring fluid permittivity in real time, automotive application? I'm new to PF and limited experience, so all the help/details you can provide are greatly appreciated.

if you connect a DMM across a 120V peak AC signal what should be your output in DC mode??

Say you have a conductor (a single straight wire) which goes from left to right across your computer screen and moves up and down in periodic motion in a constant magnetic field that goes into your computer screen (see diagram below). (note: you can ignore the computer screen, and you can...

Homework Statement ac with R-C coponents. Determine the tensiondrop over a capacitor in a circuit with ac. Homework Equations The Attempt at a Solution In the solution they use components of the V in sin and cos for the V of the capacitor but should it not be squared and then the...

i have an electric winch that runs off a 12v dc car battery and i want to run it off of 120v ac house electric current. is this possible, and if so how would i do it? thanks for any help

Homework Statement Hey. I am new here. Recently i got a C assignment (computing) in which i was given around 20 files..each with thousands of AC voltage test samples sampled at 1 ms..so technically 100 samples= 1 second. I was told that there 3 different kinds of frequencies in the files and...

Homework Statement Hello, I have one hard exercise, that I can't do. Sorry for my English, it's not my mother tongue, but maybe somebody could help. To charge a battery with direct current I, it takes t=8 h. But they didn't have a DC supply, so they charged it with AC, that was rectified...

greetings, when a transistor in common emitter configuration is given a ac signal with base current,the amplified output form from collector of it gives inverted polarity of the input voltage or the output graph of voltage versus time gets inverted of input graph of voltage versus time.how 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...

OK, here's what I'm doing: I currently have a single 20 watt halogen puck: [PLAIN]http://www.lightingfx.com/media/images/product_category/ro29.jpg powered through a rectifier from AC. The reason I've done this is because I need the interrupt the AC with a light timer switch. I want...

I'd like to stick an ac adapter onto a circuit such that when the adapter is plugged in it runs on the ac adapter, but when it isn't plugged in it runs on batteries. Anyone know of a quick elegant solution? I'm sure these circuits get made all the time, but I can't seem to find any! I'm...

1. The problem Remember that acceleration is a change in velocity. There are 3 driver-operated controls in an automobile that will cause the automobile to accelerate. 2. The attempt at a solution Is it axis of rotation, tangential speed, and uniform circular motion?

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...

Hello, I have a small 9hp engine with electric start and a stator that puts out between 5-18 volts ac, it only has one wire coming out and would like to convert it to dc to run lights and charge my battery on a cushman scooter. any help would be appreciated...

Hi, I have a basic understanding of electrical wiring from when I was in school, and have a question that I have always wondered about that I hope someone could answer. My electrician mate tells me for household wiring its important for active and neutral wires not to be mixed up. That...

Homework Statement An electric motor draws a 1A (rms) from the 230V (rms) mains. and is found to shift the phase of the 50Hz alternating current by 30% of the period. What is the self inductance of the coils in the motor? Homework Equations The Attempt at a Solution i've started...

Homework Statement If possible, find reasons why the resistance of a resistor may have a different value when measured with a sine wave signal (a.c.) than when measured with a d.c. (dirrect current) source. Homework Equations The Attempt at a Solution Please correct me if anything...

My knowledge of AC voltage is very basic but I have a question. I stumbled upon this by accident. If you take a piece of aluminum, stick one one end into the ground just a little, say 1". Then take a volt meter, stick one lead into the ground, the other lead anywhere on the aluminum...

Why is AC more dangerous than DC even if the peak voltage of AC is the same as the DC voltage? This is a problem from our exam. Before I read the question I always thought that AC is more dangerous than DC because at the same voltage, AC voltage is higher as it has a peak voltage than DC. I've...

Homework Statement Hello i just have an interesting question, and was wondering if my answer to it had any validity. Ok so i did an experiment The Current balance experiment(for everyone not familiar with it, you can google it and get all the info you want) to try and estimate mu naught...

Homework Statement A series circuit contains only a resistor and an inductor. The voltage V of the generator is fixed. If R = 12 ohms and L = 4.5 mH, find the frequency at which the current is one-half its value at zero frequency. Note: The ac current and voltage are rms values and power is...

Homework Statement I have three questions 1. How do you find AC voltage across resistor when there are both AC and DC current? 2. is AC voltage across a resistor different from voltage across a resistor? 3. Find AC voltage across Resistor (in this image) http://img199.imageshack.us/i/acv.gif/...

I am constructing a small wind generator for a college project. I want the 0.1 V AC output of the generator to charge a battery. To do this, I need to convert the current into DC. I am familiar with things like bridge rectifier circuits, but the smallest diodes I can find have a forward "turn...

One of my friend says that it is possible that there will be no magnetic filed around an AC current carrying wire but he did,t know about the reason. can anyone give the reason

Homework Statement You don't even have to read the whole thing... just the red part is sufficient. I saw this on the homework: V= (100 v) sin (1 000t) What does this mean? ----- Can I treat it as having 100 real magnitude and 0 imaginary magnitude (and therefore 0 phase angle)? or does sin(1...

Hello, My prof showed a way of dealing with difficult circuits using complex numbers. But I have no idea what he was on about, and can't find that method in any book. Does someone know what I'm talking about, and can someone point me in the way of some materials for this? Thanks!

Homework Statement I am given an RC circuit with an alternating current. The circuit contains a capacitor and a resistor in parallel. Part (a) says "Use KCL to find a differential equation for I in terms of V." Part (b) says "For an applied voltage V = Voexp(iwt), find the current I."...

Hi Everyone, It is great to be here. I have a problem concerning the estimation of power of AC Adapters that are used for the charging Forklifts batteries. What data would I need to calculate the Power of such charger / inverter ? Thanks, Marcin.

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 The output voltage of an a.c. generator is \emph{V}=\emph{NBA}\omegasin(\omegat). When the voltage is connected across an inductor, the rms current in the inductor is found to be 10mA. What will Be the rms current if the rotating speed of the coil inside the generator is...

Hi My GEM PK5(keyboard) ac adapter broke down. I used an alternative ac adapter on 12 volts but the whole keyboard shuts off and then on everytime I play on the keyboard when the volume is high enough. The original keyboard is big in size and the alternative ac adapter i used is small I am not...

I have a company that makes electrical resistance heaters. We have an application where we are trying to achieve 60 or less watts in a 5' 120VAC heater. The problem we have is that the heating element wires need to be on the order of 24ohms/ft and that ends up being a small gauge wire (ie 40 ga...

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...

In a typical full-sized home AC system [central air] is there a problem with oversizing the condenser? In particular, the idea is to add a pre-cooler just before [above] the condenser. This would provide additional cooling as well as increasing the volume of the system. I tend to assume that...

So i know the whole picture starting from power from the generating plants that go all the way to our homes..and the ground serves as a return path to complete the circuit..What i don't get is...how does that current find its way back to the source through ground?..is the source somehow...

Regarding this topic, https://www.physicsforums.com/showthread.php?t=421945" a question sprung into my mind. How many conducting cables go to my home circuit to deliver the power from the grid? If heard these electrician's jargon words: 1) phase (up to 3) 2) null 3) ground...

Can anyone tell me what the most standard way of changing the frequency of an AC power supply is? Can it be done with circuitry or does the method of generation need to be set at the desired frequency?

Hoping that one of you electrical wizards may be able to help me out! I have a 30A DC HP power supply and a 1000W stereo amp that I want to use create a 10mT static DC magnetic field superimposed on top of a 1 mT AC magnetic field. To generate the AC field I have a 1 uF snubber cap. in series...

Homework Statement A resistor of resistance R is connected to an AC generator with EMF(t)=(EMF_max)sin((w_d)t). (a) Write Kirchhoff's Loop Rule for this circuit at a particular instant of time. Is your result a differential equation? (b) Find the current as a function of time. Now...

I have created blueprint for a DC generator.THEORITICALLY it is 100% power efficient,it involves no AC in PRODUCTION,i need to know whether AC devices we work daily cope up with dc power or not?