Poles Definition and 240 Threads

three phase induction motor can have minimum two poles, so synchronous speed of the machine can be 3000rpm. While single phase motors have two windings - auxiliary and main winding, so minimum number of poles in single phase winding is 4??!...am i right?

Neglecting equatorial bulge and using 'g' (9.81m/s^2) as standard before calculations, I wanted to see if I could calculate the change in 'g' before looking it up. Obviously this not a difficult sort of problem but I am finding myself a tad confused about something. It seemed intuitive to me...

Hi, I have a difficult time trying to perform the following integral, $$ j({T}, \Omega)=\int_0^{ T} d\tau \frac{\tau^2\exp(-i\Omega\tau)}{(\tau-i\epsilon)^2(\tau+i\epsilon)^2} $$ The problem is that the poles ##\pm i\epsilon## when taking the limit ##\epsilon\rightarrow 0## are located at...

Hi everyone, The charged particles in the magnetic field around the neuton star, is accelerated along the magnetic field lines, which would go in a curve, from the north pole to the south pole. Due to the acceleration the particles will emit radiation, along their movement axis, and because the...

I bought a couple of bar magnets at the local hardware store. They were acting so strangely. I couldn't figure out where the poles were. Finally I realized each magnet had four poles! They weren't quadropolar, rather half of each bar was magnetized one way and the other half the other way...

Is this phenomenon explicable with the simple laws of electromagnetism alone?

Could accreting material on a neutron star’s poles impact with enough energy to initiate fusion reactions, some of which escapes the star as ultra-relativistic jets?

I've always been taught: North poles attract south poles. Yesterday after studying electromagnetism, I've a question to ask. Here's a diagram: In circuits like these, this is how the north and south poles of these electromagnets are defined. Now my question is, is the reason that the South pole...

I am a bit confused. Why ##\frac{1}{\sqrt{z}}## is branch point and ##\frac{1}{z}## is pole. And why we cannot use Cauchy integral theorem when we have branch point? Why we need to cut off branch point when we integrate? Thanks a lot for the answer.

I've studied a 2-pole IM with its winding diagram and understood how the two poles are formed. But I'm struggling to understand the same thing about a 4-pole motor. How does this winding arrangement result into 4 poles?

In reading my physics book, there was mention of different types of poles. I was hoping someone could explain the differences and possibly supply a visual representation of the poles with respect to each other as to where they lie on Earth. The different poles were the magnetic N/S, geographic...

[Moderator's note: spun off from previous thread on a different topic.] how general relativity explains the variation in value of g at equator and poles? why the twist in spacetime is more at poles than equator and not viceversa

Homework Statement Locate the poles of the response function \alpha(\omega) in the complex plane for an LRC circuit. Homework Equations \alpha(\omega)=\frac{-i\omega}{L}\frac{1}{\omega_0^2-\omega^2-i\omega\gamma} \omega_0^2=\frac{1}{CL} \gamma=\frac{R}{L} The Attempt at a Solution So we've...

Homework Statement Homework EquationsThe Attempt at a Solution part a[/B] $$ \vec {x} = \left [ \begin{array}{ccc} X-X_{s} \\ S-S_{s} \end{array} \right ] $$ $$ \vec {u} = \left [ \begin{array}{ccc} S_{0}-S_{0s} \\ \frac {F_{0}}{V}- \big (\frac {F_{0}}{V} \big )_{s} \end{array} \right ] $$...

Also, How do we know the radioactive decay is constant? I know that carbon dating cannot be 100% accurate because the rate of production fluctuates based on cosmic rays hitting our upper atmosphere. Why isn't this true with Earth metal isotopes? Is time truly constant? It seems like a lot...

Hi Guys :) There were donut shaped ferrite magnets used in core memory of the 50s - 70s that stored bits by being electronically magnetised in a clockwise, or counter clockwise direction. If you had a larger donut shaped magnet that was magnetised in a clockwise or counter clockwise direction...

Consider the equation ##\mathcal{F}(\lambda)=0\ \ \ \forall\ \lambda = \lambda_{n},\ n \in \mathbb{N}##. I understand that the expression ##\frac{d}{d\lambda}\ \ln\mathcal{F}(\lambda)=\frac{\mathcal{F'(\lambda)}}{\mathcal{F}(\lambda)}## has poles of order 1 exactly at ##\lambda_{n}## because...

Hello, I want to know determining the number of poles by inspecting coils inside the motor. Generally, there are formulas allowing us to plug a frequency, an rpm, and give off the number of poles, or we can just simply look at its nameplate. My reason for needing the inspecting is that my...

Hey guys, I am learning about the filter shapes deduced from the poles and zero plots, however a lot of sources are describing it differently with no logical explanation. I want to know what exactly the poles and zeros do between the range Ω = 0 and Ω = π. One source i read explains if the pole...

I am trying to calculate a pole of f(z)=http://www4b.wolframalpha.com/Calculate/MSP/MSP86721gicihdh283d613000033ch4ae4eh37cbd4?MSPStoreType=image/gif&s=35&w=44.&h=40. . The answer in the textbook is: Simple pole at...

Suppose we have a complex function f(z) with simple poles on the complex plane, and we know exactly where these poles are located (but we don't know how the function depends on z) Is there any way to build up the exact form of f(z) just from its poles?

I wanted to know thta how the poles are generated specifically for induction motors..?? I am not getting the main concept behind it that how the poles are being created with flowing current and with reversal of current the poles become alternatively north & south?

I have several bar magnets with the north and south poles labeled on them. It is my understanding that a compass itself is a tiny magnet and the north (often the red part of the compass) end is itself a north polarity. This means that this end would point towards a south pole of a magnet. From...

Homework Statement Show that all the singular points of the following functions are poles. Determine the order of each pole and the corresponding residue. z/cosz Homework Equations maybe cosz = 1/2 ez+e-z is relevant but i don't use it here The Attempt at a Solution the pole i found was z =...

Homework Statement In order to use cauchy's residue theorem for a question, I need to put ##f(x)=\frac{z^{1/2}}{1+\sqrt{2}z+z^2}## Into the form ##f(x)=\frac{\phi(z)}{(z-z_0)^m}##. Where I can have multiple forms of ##{(z-z_0)^m}## on the denominator, e.g...

Homework Statement I am trying to understand what is meant by "poles can be used to obtain the form of the system response'' This is an example for a transfer function (s+2)/(s+5) and a step function input http://postimg.org/image/97vnos9uz/ Homework EquationsThe Attempt at a Solution For...

I have several questions about poles and towers. a. Does all of transmission towers carries three-phase powers? Is there no transmission towers designated for single-phase? b. Does all towers are for transmission purposes only? Is there any towers in the world used for distribution instead of...

What is the reason for the analogy that a magnetic south pole can be considered negative and a magnetic north pole positive? I understand magnetic field lines run from North to South and electric field lines run from positive to negative. Is this the only basis? Or are the magnetic poles...

When watching some videos about neodymium magnets, I came upon a very interesting phenomenon. Namely, the maker of the video put a large magnet near an old CRT TV. At first, a big black spot appeared on the screen. This means that the electrons were repelled from from the magnet and didn't...

I am working on problem a professor gave me to get an idea for the research he does, and have hit a point where I'm having a difficult time seeing where I need to go from where I'm at. I would also like to go ahead and apologize for not knowing how to format correctly. I was given that a...

If a battery has 6V of voltage, this means that P+ – P– = 6V or that P– – P+ = 6V ? Being: P+ = electric potential of the positive pole P– = electric potential of the negative pole

Hi folks, Been trying to fill some of the more formal gaps in my knowledge by tackling the more technical stuff in P&S Chapter 7. Their derivation of the LSZ formula is quite different to those of books like, say, Srednicki, as they basically Fourier transform the whole argument as I...

The root locus design method is used to locate poles at desired locations. However, it is not possible to locate poles arbitrarily. Provide reasons for this statement. K = 1/│G(s)H(s)│ K G(s)H(s) = (2k+1)π I've formulated the answer for this as, The root locus gives the path of...

Hello, I was reading over poles and filters, but I guess since I don't learn calculus, I don't learn transforms. With that said, the definition of Poles in my text is a bit iffy... It talks about how the term poles means how many bypass capacitors are in a circuit. I can't find ANY definitions...

Given the transfer function G(s) = 1 / (s(s+1)(s^2 + 4s + 13)), how would I determine the range of the values of K>0 such that the closed-loop poles are in the left-hand plane? Picture of block diagram with transfer function: Not sure if this is right at all, but I know that a system is...

This topic is not an application of the ordinary Residue/Cauchy-Riemann theorem, this is a search for any integral occurring within physics (or statistics/math which aren't tailored examples, but that's not the focus for my participation on this forum), which fulfills certain conditions: Do...

hi, There is one thing that I do not understand and nor do I find any direct explanations for it. Is there any relationship between no of rotor poles and no of stator poles in BLDC motor (or PM Synchronous Motor)? I have read somewhere there doesn't have to be. I can imagine if no of poles are...

Homework Statement Understanding the bode plot for, G(s) = \frac{1}{2s-1} Homework Equations The Attempt at a Solution Usually when I am drawing bode plots for either real poles or zeros, I simply solve for the break frequency knowing that a zero/pole will give me a +/-20dB/decade asymptote...

Hello, I know the magnetic field produced by a direct current flowing through a solenoid has a north and south pole, so how about the magnetic field produced by a current flowing through a straight conductor, does it have a north and south pole too? If it have them, where is it located? A...

Which equation is correct I have seen both- F=N/60*P Or F=N/120*P This is Frequency, N=RPM P=Poles

In the process of calculating the integral \int_0^{2\pi}\frac{\sin{x} \cos{x}}{\sin{x}+\cos{x}}dx by contour integration,I got the following: -\frac{1}{2}[ \LARGE{\oint} \large{\frac{z^2}{(1-i)z^2+i+1}}dz-\LARGE{\oint}\large{\frac{z^{-2}}{(1-i)z^2+i+1}}dz] Where the contour of integration...

\[ \int_{-a}^{a}\frac{dx}{\sqrt{a^2 - x^2}\big(x^2 + b^2\big)}, \quad a,b\text{ real} \] So we have poles at \(z = \pm ib\) but...

Hi guys i wanted to clear out some confusion, Suppose $\text{z=a}$ is a simple pole, my Professor classify it as follows: Simple Pole at z=a Type 1: $$f(z)=(z-a)^{-1}g(z),g\in H(D(a;r)):$$ $$Res\{f(z);a\}=g(a)$$ Type 2: $$f(z)=\frac{h(z)}{k(z)},h(a)\neq 0,k(a)=0,k^{'}(a)\neq 0:$$...

Hello, I need some help understanding this question. If we take a mass of a person as 100kg, what would he weigh at the poles and the equator, in Newtons? How do I do this please? Thanks and much appreciate some help.

In multipole generators, why do the poles facing each other have the same polarity? Wouldn't this give rise to a zero net current? Consider this link: http://electriciantraining.tpub.com/14177/css/14177_40.htm Initially, it gives the example of a simple generator with opposite poles...

Suppose you have two poles separated by the distance $w$, the first of height $h_1$ and the second of $h_2$, where $0<h_1<h_2$. You wish to attach two wires to the ground in between the poles, one to the top of each pole, such that the angle subtended by the two wires is a maximum. What portion...

I have a little trouble with positional astronomy so I wanted to clarify a few things to get my understanding right. The imaginary celestial poles are located directly above (or below) the poles of the Earth, right? And the Zenith is the position in the sky that a person would look if one was...

Hi all Here, I attached a figure presenting the Lorentz-Drude function. The resonance number is clear from the m in the equation. But I like to know if the number of poles in Lorentz model is the same as the number of resonance or not. I am confused. I would be very grateful if you can help me...

I'm working on a few questions for an assignment but am unsure whether my approach to this type of question is sufficient or valid. I will show my solutions to two problems that are not part of the assignment just to ensure my method is correct. "...locate each of the isolated singularities...

Im a little confused...If a black hole has a true point of singularity how does it have magnetic poles, and how does it have jets of charged particles shooting out from its poles,how does this escape the event horizon if light cant? are black holes real?