What is Ac: Definition and 1000 Discussions

The problem is shown below: (I am only asking about part b) ^Above is the problem. Below is the solution to part b. They have claimed that we can set potential at C = D = u(t), and A=B=0. Why is this claim true? What I realize: By applying Kirchoff's across ACDB, Voltage across C1 = Voltage...

I thought about this for some time but I can't seem to really understand the cause. Now I remember some time ago using a transformer for my self made soldering iron, I wound it to have the right temperature at about 45 VAC input but I guess I missed a bit , so that when I connected it to the 45...

I have a source of electricity that's alternating but at variable frequencies. So an asynchronous alternating current of sorts if you will. Can industrial rechargeable batteries be charged like this efficiently? Or would DC current work best? Or normal AC?

Hi! I'm trying to understand and solve this circuit by Node Voltage Method. I have to calculate u(t). In my mind, I don't have any idea if any current should go through Z1 in my calculations. I would be grateful if you could write even equations for this circuit. Is 'a' just a prefix to multiply...

The below are the formulas i have seen from the book, but no particular formula for the peak power Instantaneous power ##p(t) = v(t) i(t) W## ->eq1 Average power ##p(t)_{avg} = \frac{\int_{t_0}^{t_0+T} p(t)dt} T W## ->eq2 a. Instantaneous power ##v(t) =A\sin(\omega t)## ->eq3 ##i(t) =...

My attempt at solving this question: I realized my attempt is wrong however I just don't know how to proceed in the first step. How can I calculate the phase shift? and find Voltage and Current in phasor form??If I know that, then I can use power factor formula: pf=Pav/V*I

I have an AC brush motor it has 12 slots where copper wires go and 24 copper bars, if you take 12 wires and go in a slot and come out at different slot and as you go around you filled all the slots now you have 24 ends 2 wires out of each slot which you connect to the 24 copper bars. Heres the...

I've attached my attempts at the solution and the actual question below. I believe the only issue I am having is I don't know how to get rid of "I" in both my final inductor and capacitor equations as the HW states I shouldn't have anything in term of I. I believe I need to put "I" in terms of...

Assume a transformer as above, with 230V L-N, and I want to work out the L-L voltage. A phasor diagram will show me that the voltages are 120° out of phase. (230∠0°) + (230∠120°) = (230cos0 + j230sin0) + (230cos120 + j230sin120) = 230 + (-115 + j199.2) 115 + j199.2 = 230∠60 What I’m looking...

Hello! I think I am a bit confused about the AC Stark shift effect. Assuming we have a 2 level system with energy difference ##\omega_0## and we apply a laser of frequency ##\omega## and Rabi frequency ##\Omega##. If we look at the problem in a frame rotating at the laser frequency, before we...

I need to create a 5 V stable DC supply out of 6 V AC from a transformer. By "stable", I mean that I do not want the ripples in the voltage that one gets from the output of a full-wave bridge rectifier. I have to feed this to two ATmega 8A μCs. I am going to create the following circuit: 6 V...

The voltage and current are given as ##v(t) = 359.3\sin(\omega t + 15) volts ## and current is ## i(t) = 100\cos(\omega t + 5) ##. My question here is do i need to convert the voltage into cos terms or current into sin terms. suppose if i convert the voltage into cos terms, the calculations will...

Attached is the section from the book. I am doing section 31.3 We know that an AC source gives a sinusoidal varying current, and as far as I know its always given by ##i(t) = Icos(wt)##. Its like we take the current to be the base of all other quantities, so we use it to derive everything else...

When I record slow motion video of my filament bulb lamp connected to mains, I can be completely sure that it flashes 25 times per second. This is half of the 50 hertz AC frequency. I would expect it to flash 100 times per second as the current reaches a node twice per cycle in it’s AC wave. Why...

Hi. At school, I once worked with a Teltron tube that looked very much like this (I don't remember the brand): The electrons are emitted from a coil that must be heated with a voltage around 5 V. But for some reason, it must be AC, it doesn't work with DC (and it took me a long time of...

I would like to ask a question about the induced voltage of an AC generator. So, according to a graph I found on Google, the maximum induced voltage is reached when the loop is parallel to the loop. (The graph shown below.) Then I was wondering, what if the loop is initially (when it is at 0...

I integrated the second equation given in the form (integral)di= 1/L * (integral) V *dt and I got an answer of 3.52 for the current at 0.4 seconds, anyone can let me know if this is correct?

Hi I'm doing a uni project and need help with a Self Excited AC Single Phase Generator. I'm using an AC Single Phase Induction Motor to act as the generator. Its turned by a DC Motor The AC motor is 1350 RPM and the DC motor is 2500 RPM Its not producing any electricity (just a few volts) for...

Hello, I am looking for some information on how 2 different types of magnetic fields interfere with each other. And i don't mean, 2 magnets, but let me be specifically: Lets say that you have a very strong static magnetic field, from a huge magnet. (for instance, the strength of the magnet of...

Consider a purely inductive circuit with an inductor of self-inductance ##L## and sinusoidally varying AC source of peak voltage ##V_{m}##. First of all, Why is ##V_{ac} = ε_{ind}## (where ##ε_{ind}## is the back emf)? Now, at ## t=0 ##, voltage is increasing at a fast rate. Hence, due to the...

*Please refer to the attached question file

I have an object that will be under DC excitation in operation but will be qualified using 60 Hz AC. Because of this, I am interested in 2 simulations. 1) I would like to simulate E-field intensity representing a 60 Hz excitation. Do I need to do a transient simulation to truly get this value...

Anybody knows how to take this off because when I m doing for example 0.025 ÷ 2 = is showing the answer with a fraction.

Consider a circuit with a witch, capacitor and an AC voltage source. The sinusoidal AC voltage source is depicted in the following graph: We know that, ##Q = CV## ##\frac{dQ}{dt} = C \frac{dV}{dt}## ##i = C\frac{dV}{dt} \tag{1}## So from the graph, the voltage increases rapidly around ## t =...

Hello! Can someone explain to me in an intuitive way (or a nice mathematical demonstration) or point me towards some accessible papers about the AC Stark effect (Autler-Townes effect)? I am mainly confused by how can one start from a 2 level system (consider a 2 level system for simplicity) add...

Right triangle ABC is given with angles A, B, and C, where angle C is 90 degrees. Angle A is 60° and side AB = 12 cm. Find sides AC and BC. Here is the set up. To find AC: cos (60°) = AC/12 To find BC: sin (60°) = BC/12 Is this correct?

Preface to thread: I am darn well aware of the fact that on an AC circuit, there has to be a line 2 after the load to bring current back to the power source. This thread is about WHY does there have to be a line 2 after the load to bring current back to the power source. I hope that I don't...

For underground AC transmission, the line charging current prevents the lines from exceeding 100 km due to the close proximity and high capacitance between the line and ground. If the line was made with superconducting material, I think the same distance limitation applies (assuming same power...

In my city (USA) typical older houses have "100 Amp service" so their peak electric usage is limited to 100 Amps. In considering what sort of electric air conditioning system to install in such a house, peak usage is major consideration. Generally speaking, which type of residential unit...

Here, at voltage source zero crossing, cos(2to + pi/4) =0. So, 2to+pi/4 = pi/2 This gives to=pi/8 = 0.3926s. But the given answer is twice the answer I got i.e. 0.7852s. Have I missed anything here?

In parallelogram $ABCD$, $\angle B$ and $\angle D$ are acute while $\angle A$ and $\angle C$ are obtuse. The perpendicular from $C$ to $AB$ and the perpendicular from $A$ to $BC$ intersect at $P$ inside the parallelogram. If $PB=700$ and $PD=821$, find $AC$.

I will use examples of actual products: 1) 3 hp (2.2kW) 3 phase 2 pole AC Induction Motor 3 hp/2.2kW three-phase induction motor features 2 poles, 2840rpm rated speed, and 7.4Nm nominal torque, with a working voltage of 380V 50Hz. Cheap 3-phase asynchronous motor has outstanding performance in...

I have calculated V3 to be 294.62sin(1800 pi t + -0.56)V I am confident this is correct but I now need to work out the frequency of the waveform, I believe it may be 900 but I am not too sure if my calculations are correct and I can't find anywhere on line that aids me in this particular instance.

Hi all, In an LRC AC series circuit, at which frequencies are where you are mainly dumping your generator/current energy into capacitor to create electric fields or into the inductor to create magnetic fields? So, for example, at low frequencies, f --> 0, the impedance of the inductor goes to 0...

I was wondering about , have there been or are there any systems that would use a large capacitance rotary capacitor/s as a mechanism for soft start of larger AC motors and also they would serve as power factor correction devices? The idea is basically simple, say one has a 3 phase motor and we...

I used to work in HVAC. There are three main types of alternating current (AC) motors in residential air-conditioners and heat pumps: outdoor fan motors, compressors, and indoor blower motors. All three types of AC motors have the maximum number of amps stated on the nameplates of the units...

Hi, Scenario: Given a powerplant is being provided a constant power source - like steam is being produced at a steady rate, so that the generator rotates at a constant speed, and in turn, produces a constant electrical frequency. And, suppose, hypothetically, all the power being used...

In this example I am thoroughly confused on why Is is divided by sqrt(3). My understanding is that the transformer supplies 3 phase (which is always described in line to line or Y connected). So the current in the winding should be 120[KVA]/230[V] then multiplied by sqrt(3) to convert it to...

Why do the magnetic fields in-between the wires does not seem to cancel? Even those outside each wire? (the fields do are not in opposite direction). Yet most of the people I have talked to until now says that such magnetic fields do cancel? I am confused...

I = A_0 * sin(n_0wt + p) + A_1 * sin(n_1wt + p) + ... +A_n * sin(n_nwt + p) Looking at the equation, it only contains sinusoidal waves. Further, there is the possibility of waves having the same shift or no shift at all and even, having the same frequency. Is it really valid or correct to use...

No attempted solutions.

Hi all, Kirchhoff's equation for this simple circuit is equivalent to \dot I=\frac{V}{L} Where V=V_0 \sin(\omega t). Integrating both sides should give I(t) = -\frac{V_0}{L\omega} \cos(\omega t)+c where c is an arbitrary constant (current). Here, most of the derivations I've found simply drop...

Hey fellas, I’m trying to apply a variable phase shift (0 to 180 degrees) on an AC signal generated from a Variable Frequency Drive (VFD). The frequency is variable and ranged between 10 and 50 Hz. the voltage amplitude is also variable between 10-50Volts (this shouldn’t be a problem I suppose)...

If I consider a wire carrying AC current, I know that at an AC frequency of 0Hz, the current will always in the same direction. If I change the frequency to 1Hz, the current will flow left to right for 1 second and then right to left for 1 second. I guessed that at these higher frequencies, as...

By combining the formula for the reactance of a capacitor with Ohm's Law for a capacitor, I can solve for angular frequency, and divide by 2π to find frequency. The resulting equation is: f = I/(2π VC) Using the given values, I end up with 5.2 kHz, instead of the correct answer of 5.2 MHz. I...

Hi! I wonder if it is correct. Can someone confirm (maybe with a software) ? I(L) = I2 I(C) = I2 - I3 -- Thanks.

When an alternating current motor first turns on, what causes an alternating current motor to pull locked rotor amps for approximately one second after first turning on as opposed to just pulling the same amount of amps the entire time? What causes the amperage on an AC motor to drop after...

Hi! I was watching some random videos about electricity on you youtube and then got this question: if AC changes direction constantly (50 times per second) then why is it still important to connect live to live and neutral to neutral in wall outlets? For example some wall outlets have different...

I am getting one of those $10 WIFI units from china runs on 120 volt AC and I want it to run off of 12 volt DC car battery I am thinking will need to open up unit and try to figure out what the DC voltage is that is coming from the AC supply unit and then insert a fixed regulator of 12 or 5...

This is the circuit: I try with KVL: But the given answer is 6.66L33.67 Volts. So, I'm confused, any suggestions ?