What is Ac: Definition and 1000 Discussions

Homework Statement provide a detailed review on how alternating current is produced and the relation that determins movement and current flow direction. Homework EquationsThe Attempt at a Solution I know the basics of how AC is produced- AC is produced from an alternater (type of generator)...

Homework Statement why is there a loss of energy in DC circuits and power loss is reduced in AC when transmitted Homework EquationsThe Attempt at a Solution Loss of energy in a DC circuit is due to the resistance of the wire cauing the wire to heat up therefore energy is being lost by heat...

Homework Statement similarities and differences of AC and DC current in simple circuits. Outline using diagrams and a clear desciption the loss of energy in DC circuits and power loss reduction of AC when transmitted. Homework Equations N/A The Attempt at a Solution DC loses energy over long...

Homework Statement Homework EquationsThe Attempt at a Solution I don't understand why would the current be zero in any of the branches . May be I am missing something very fundamental . Please help me understand this question .

Homework Statement In an ac generator Voltage is maximum when the coil is parallel to the direction of magnetic field (B) Voltage is minimum (0) when the coil is perpendicular to the direction of magnetic field (B) I'm trying to understand why. Homework EquationsThe Attempt at a Solution A...

Homework Statement For a series LCR circuit,the voltage across the resistance,capacitance and inductance is 10V each.If the capacitance is short circuited,the voltage across the inductance will be (a)10V (b)10/√2V (c) 10/3v (d)20V Homework Equations Potential difference across...

Hi, I have a problem understanding the ac capacitive circuit, where Vc = Vm * sin(ωt), and, current leads the voltage, so at t = 0, v = 0 which means no emf, no pushing energy for the electrons, I think, then how current is max? what is the energy source that supplied the electrons with the...

Hi everyone! This is my first thread :) I've been working a bit with AC and radio, and would like to make a simple(-ish) circuit in which a 1-volt peak audio signal is stepped up to around 5 volts with a transformer, and is fed into a crystal oscillator to make a crude-but-effective AM...

Given an ABCD.EFGH cube whose its side length is 8 cm. The point P is within AB so that AP = 3PH. The distance between P to AC is ... A. 2\sqrt3 cm B. 3\sqrt3 cm C. 2\sqrt6 cm D. 3\sqrt6 cm E. 4\sqrt6 cm So AH is 8\sqrt2 cm and PH = 6\sqrt2. What do I do now? Is the triangle HPC a right triangle?

does the magnetic field created by AC alternate? reverse poles? if so why does a motor rotate the same way every time? does it alternate in three phase as well? thanks, if you want to direct me to literature i would appreciate that, what i have in my motors book talks about the hand rule for...

Homework Statement 2. The attempt at a solution Am I doing something wrong? I know it's just voltage division with AC phasors and we have to equate the real parts and imaginary parts to find the unknown, but I feel like the question shouldn't be this hard.

Homework Statement Homework EquationsThe Attempt at a Solution I am assuming that the given value of voltage applied is an RMS value . Same voltage is applied across both the branches . In the upper branch the net resistance is the sum of capacitive reactance of the capacitor and...

Dear community, For one of the projects which I am currently working on, I want to quantify my three phase AC induction motor in the following ways: 1. Find Torque vs RPM Curve 2.Find Efficiency vs RPM Curve Now since I don't have the industrial "Torque Sensor" to plot Torque vs RPM curves, I...

Hi, I have a question about ac component and dc component of a source. For example, there is a current source connected directly to a resistor. If the current source supplies a sine wave with no dc offset, then I understand that power supplied by dc component is zero, and so power absorbed by...

A 4160v chiller motor is drawing too much power at start-up. Utility company only let's them run it once or twice a year because of it. It dims all the lights etc.. It was originally a primary reactor starter (2 contactors). The PR was replaced with an auto-xfmr and wired the same. So now it’s a...

How is the phase difference between the current in the primary coil and induced e.m.f. in the secondary coil be 90*??

Ok so I've been reading a book on electronics and I got to a section that talks about full-wave bridge rectifiers. This is the diagram the author gives: In this diagram he says the D2 and D4 diode are forward biased. But, doesn't the current flow through D2, goes through the resistor, and then...

I was vacuuming my house, the vacuum cleaner is 1600w rated I remember, then i unplugged the cord from wall socket and I observed something interesting , and to be honest I remember I have seen this before with my washing machine and elsewhere, when I take out the plug from the wall socket I...

I'm having trouble figuring out how to solve Maxwell's equations for the electric field of an AC wire. I assume the Voltage waveform in the wire is 120sin(60t). This circuit only has a 14ohm heater in it, according to Ohm's law I=V/R. The current is equation to I(t)=120sin(60t)/14 It is...

So I was messing with the induction from power lines and fluorescent bulbs, and I noticed all the plants under the power lines were dead but plants around it were fine. Do EMF's have something to do with this?

my transformer book does not cover an area i am interested in and was wondering if someone would direct me to literature that would help me understand something and if you wouldn't mind trying to explain it to me yourself that would also be appreciated. you have three single phase transformers...

i was desigining a simple ( simple as in no MPPT) PV-pump standalone system, and we decided on using an AC-pump, so while i was searching for inverters i noticed the remarkable difference in price ranges, so i started to read about the difference between the two, so far the disadvantages of the...

I am trying to build a Voltage Doubler to use a motorcycle 6 Volt a.c. alternator's dedicated headlight coil (which presently runs a 36W incandescent headlight bulb) to provide 12 Volt d.c. to drive a commercially-bought 12V LED headlight unit (also rated at 36W). Frequency will be (1500 ~ 5000...

Hello, I have a very basic question. And, admittedly, my knowledge is limited in this field. It is about the rpm of a rotor inside a generator. I know, to be aligned with the existing grid, standard frequency (of 50Hz, Europe and 60Hz, US) will require the RPM to be 3000 and 3600 respectively...

I'm trying to measure high voltages with a DAQ card. Obviously I'm going to have to attenuate the voltage, but I need to make sure that I can measure accurately (within 1%) The code width of the DAQ is Vcw = 20Vpp/2^16 = 305.176uV For this code width to be within 1%, the minimum voltage I...

Hi, did you ever get to understand why a fuse installed in the Hot (Live) conductor of a circuit doesn't rupture when the AC Polarity reverses with the Neutral conductor bonded to Ground ? I still don't get it i.e. if current flows in both directions then the polarity is allowing the Hot wire...

Homework Statement Q1: A power plant produces energy at a voltage of Vi = 18667 V. Before being sent along long distance power lines this electricity is sent through a transformer with 143 turns in the primary coil and 8971 turns in the secondary coil. Voltage is calculated to be...

Homework Statement [/B]Homework Equations Can I use KCL at the central node? The Attempt at a Solution I tried KCL and got: 5cos0 + j 5sin0 + 10 cos 60 + j 10 sin 60 = (-I1) 5 + 5 + j 10 *1.732 / 2 = (-I1) 10 + j 5 * 1.732 = -I1 This gives 13.33 angle (220.89) Book answer is A Is the 5 and...

Is it true that AC synchronous motors (the ones with the DC slip rings and excitation current running into rotor poles) have a power factor of 1.0 when they run in synchronous mode? Would that be because with sufficient rotor DC current he rotating AC magnetic field is precisely counterbalanced...

Homework Statement For AC Circuit shown in the picture, ##C=60nF##, ##L=100uH##, ##X_3=-100Ω##, ##Z_2=50Ω## and ##Φ_2=\frac {\pi}{6}##. When the switch is closed the ammeter shows a current ##I_1=0.6A## and the voltmeter shows ##U_l=60V##. The measuring instruments mentioned are ideal...

If i connect 2 capacitors in series with an AC source ,and an output ,then how exactly will the phase vary with input source ? A single capacitor makes a 90 degree phase difference with the current,if I don't want that ,what steps can I can take to change the phase difference to 0 ?

Hello, new member here. I'm giving myself a crash course and can't find a direct answer to my query outright, so here I am: Do A.C. generators make use of interpoles? I understand the concept of interpoles in D.C. machines, offsetting neutral plane shift; however, if we have, say, a brushless...

Homework Statement Homework Equations I think both A and C are right answers. The Attempt at a Solution 1 condition is pu Z(leakage) must be same on respective KVA rating for load sharing. Now: Zpu = Z(actual)/Z(base) ----equation 1 For Zpu of both transformers to be same, the right side...

Hello Everyone, I have a question about the type of signals that are used in projects involving the microcontroller Arduino or similar ones. It seems that the currents and voltages in these microcontroller's projects all unidirectional, i.e. they can vary with time in different fashions but...

I want to program a little power grid game and have the problem of connecting things via transformers. Imagine the following setup: You can see the AC voltage sources as generators (or together with the resistor as a "consumer", if the amplitude is 0). What I need to figure out are the...

Homework Statement More than one options may be correct . Homework Equations Inductive reactance =ωL Capacitive reactance = 1/ωC The Attempt at a Solution On increasing the frequency , inductive reactance increases whereas capacitive reactance decreases . Thus , option a) is correct ...

Homework Statement Homework EquationsThe Attempt at a Solution I believe none of the options are correct . Option c) would have been correct if E represented peak voltage , I represented peak current and Z is used instead of R . But I suppose the question is considering E to be E(t) and I...

Hello and thanks for looking at this question. I have a semi-conducting sample which has been run on a PPMS system - measuring it's resistivity as a function of temperature. I switched to AC transport mode in order to measure the resistivity again while applying frequencies between 1Hz -...

Hi there! I've been tinkering with some homemade speakers, and wanted to make a simple amplifier circuit to step up the some 3 volts that comes out of an aux jack to 9 or 10 volts. I decided that the common-emitter model looked the easiest to understand. I was mistaken. This is the simplest...

Hello, I was thinking that using AC to supply power to a lamp would cause it to flicker, considering that the potential difference keeps changing signs. This would mean that the current supplies voltage to the lamp, only to take it back after a really small amount of time. Voltage say's...

Hi. Can anyone tell me how my AC generator is constructed. It is a Hyundai unit, the main windings consist of 4 wires in parallel, 2 sets of 6 coils, each one of the set is maybe 8 or 10 turns. There is a secondary pair of 2 windings each. This is centre-tapped, so I guess to provide exciter...

Hi, everyone. I'm working on a project right now where I need to amplify an AC signal to create as much current as possible in a solenoid to generate as strong a magnetic field as I can. I'm likely dealing with a maximum of 10 V and 10 mA from my signal generator, but I ideally need a peak...

I am retired from a major railroad co. where I worked on electronic weighing equipment. I have an associate of applied science degree from a local university. I have a basic understanding of dc and ac electricity but the explanation I recently read on this forum was the easiest to understand...

Given A(-4, 6), B(-1, 2), and C(2, -2), show that AB + BC = AC. Can this be done using the distance formula?

Hi Problem: Three loads are connected in parallel across a 12.47 kV three-phase supply. Load 1: Inductive load, 60 kW and 660 kvar. Load 2: Capacitive load, 240 kW at 0.8 power factor. Load 3: Resistive load of 60 kW. (a) Find the total complex power, power factor, and the supply current. (b) A...

Hi. As far as I know, the main reason for using AC in electric power transmission is that voltage can easily be transformed. If there was a similarly easy way for transforming DC, would power grids work basically the same? To be more specific, how much does AC power transmission rely on the...

This question is from my physics book and neither I nor my teacher can find the mistake in my method. (The original question is not in English so I'll do my best translating it) > When a coffee maker is connected to the wall (230 V, 50 Hz) its power consumption is 180 W. The power consumption...

Hi, I need to find the peak voltage of the ac current produced by the sensor connected to the alternator on my motorcycle. The workshop manual recommended a peak voltage adapter which goes on a multimeter. I don't want to buy this expensive thing. I was wondering since Vp=Vrms*sqrt (2). I can...

Homework Statement For the circuit given in FIGURE 1 the power factor is 0.72 lagging and the power dissipated is 375 W. Determine the: (i) apparent power(ii) reactive power (iii) the magnitude of the current flowing in the circuit(iv) the value of the impedance Z and state whether...

Homework Statement An A.C. voltage, V, comprises a fundamental voltage of 100V rms at a frequency of 120 Hz, a 3rd harmonic which is 20% of the fundamental, a 5th harmonic which is 10% of the fundamental and at a phase angle of 1.2 radians lagging. (i) Write down an expression for the...