Source Definition and 1000 Threads

Folks, Is there a online source I can use for evaluating Incomplete elliptical integrals ##F(\phi,k)## and ##E(\phi,k)## I do not have Mathlab or Mathematica and Wolfram alpha requires payed registration for extended computation time. Any information will be appreciated. Regards

I am going to be building a small 'monument' that will be intended to last thousands or more years. I would like to include some electronic/electrical appartus that will have a small power consumption when demanded (no power use until a button is pushed or something). My question is this (and I...

I have a question about observing a field of radiated light (and it's source) through a microscope, specifically vis magnification and the scale of the final image observed (the field, and also the source). I have a slice of field intensity at the plane of a microscope's numerical aperture...

Hi, I am preparing for my circuits final and I am having trouble with this question. Can someone guide me through it? I am trying to solve this using phasors. I know I will have to use superposition since the circuit contains sources with different frequencies. So first I start of...

Here's the scenario: I need two plates that start off in proximity (a few mm apart), and I would like to vary the charge in these plates to achieve a repulsion force. Ideally it would be varied by a voltage source, so that I have fine control over the repulsion. But as it happens, it is not...

Homework Statement I need to find the current through the 3V voltage source: picture of the circuit and the equations there: vantraveller.blogspot.ca The Attempt at a Solution I was about to get 3 equations, however, I find myself having 5 unknowns, what other equations can I write...

http://img31.imageshack.us/img31/6178/ladno.jpg The floats, thanks to the principles of buoyancy, will keep ascending, maintaining the rotation of the wheel, thus achieving the world's first neverending source of energy! Or, perhaps, there is a catch? ;)

I could not figure out definition of arc voltage and arc current. Is that true arc voltage if the potential differences between dual electrode and the current is flow through one of these electrode? any help would be appreciated.

Is there an open source math software for Mac OS X which is equivalent to Mathematica? I intend to use it for vector geometry problems (drawing planes, lines in 3-D space).

If everything has energy... Which "thing" can be an energy source? Well... If we look at everything in this world,galaxy,universe, We find that every physical object is capable of doing work... If we apply the proper "INPUT" force within a distance in this humongous universe work can be...

This is an observational exercise where I have to find several different light sources and observe their spectra through a diffraction grating, then record my observations. I need two sources of each (i.e. continuous, emission, absorption). Continuous and emission are fairly easy, but for the...

Hi. I'm new here and wasn't sure which forum to post this request on, but this one seemed a good start. I am developing a talk/seminar on dealing with legacy code. In the late 1990s I was working for a large corporation in a software capacity and one day idly wondered what the source code...

Homework Statement Mesh and nodal analysis are used to find unknown currents and voltages in planar networks. Why is it necessary when performing these network analyses that all of the source frequencies be the same? The attempt at a solution I know that superposition let's us analyze...

Hello all of you very bright physicists, The local physics dept. is not answering us thus far and long story short we need a rough estimate of the power of a light source based on wavelength and a measured concentration of photons. We need a method of converting the photon concentration...

Hello, I've read that Dirac introduced the idea of the creation and annihilation operators in the solution to the quantum harmonic oscillator problem, but can anyone tell me where he did this? In a paper, or maybe in a book? I've had a little search online, but I've yet to discover...

light O / \ / \ / \ ---*--- image The above image gets brightest in the middle, but photons get equally emitted in all the directions, so what is it that keeps them form making the whole image equally bright? Is it angle of impact? Could it be the rate by which photons...

Homework Statement http://www.wifstrand.se/Albert/stuff/p7.7-1.png Homework Equations vL = L * (diL / dt). All of the inductors can be reduced to a single 8 H inductor, so iL = (6 / 8) * ∫ cos 100t dt = 0.0075 sin 100t if you integrate from 0 to t. The Attempt at a Solution The formula...

Hello everybody! There is interest in making point-like light sources, especially to measure the quality of optics, and possibly to produce optics. Here are some ways I imagine. ================================================= Semiconductor technology can make a hole of 20nm diameter...

Homework Statement The intensity produced by a long cylindrical light source at a small distance r from the source is proportional to a)\frac{1}{r^2} b)\frac{1}{r^3} c)\frac{1}{r} d)None of these Homework Equations I=\frac{dF}{dω} I is the intensity, dF is the luminous flux of the...

Hello all. I am preparing to take my math department's preliminary qualifying exam for pure math. It covers analysis and linear algebra. I have a good number of past papers but I was wondering if there is a good source, maybe a book or a website, for problems of similar difficulty. Thanks.

In the case of nuclear fission, when U-235 splits into Ba,Kr and three neutrons , then it is shown that the total mass of the products on the right side of the equation is slightly less than that of the reactants on the left side. So this missing mass-the mass defect – is converted into energy...

Hi, I've recently been reading up on circuit electricity and as the title states have found difficulty understanding the difference between pd of a source and a component from the textbooks I've been reading. So far I am to believe that the pd of a circuit is directly proportional to its...

Please I need help to understand how diffusion current can occur in a circuit that contains an N-type or P-type semiconductor without being connected to an electric souce such as a battery.And how can both drift and diffusion current occur when the circuit is connected to a battery?

Homework Statement In the circuit shown in Figure Q8 below, if Vs = 10V, use Kirchoff’s Laws to determine the currents i1, i2, i3 and the source current is. Calculate the power dissipated by the resistors in this circuit. Confirm that the power dissipated by the resistors is the same as the...

I need help finding some animals whose application of physics in the nature have inspired people to use the same physics in inventions/different applications. Some animals I've thought of are: Bats (Radar) Dolphins (Sonar) Birds (Airplanes) Bats (Radar) These animals would be...

I need help finding some animals whose application of physics in the nature have inspired people to use the same physics in inventions/different applications. Some animals I've thought of are: Bats (Radar) Dolphins (Sonar) Birds (Airplanes) These animals would be perfect, except...

I need help finding some animals whose application of physics in the nature have inspired people to use the same physics in inventions/different applications. Some animals I've thought of are: Bats (Radar) Dolphins (Sonar) Birds (Airplanes) These animals would be perfect, except...

Hi I am searching on freeman ION SOURCE for my BS thesis. I have lots of problem about the material of the FREEMAN ION SOURCE and sizes of all the part to have the best design and better beam density. I need some details. Any help would be appreciated.

Greetings, I want to ask you somthing if i understood well this subject. Lets say we have an order 1 binary source. H(a)=-Paa*log(Paa)-Paa*log(Pab) bit/symbol. From what i understand this is the average information of a symbol generated after an "a", like aa or ab. Is it right?

I'm sending this message to anyone who has knowledge about neutron generator. is there anyone who knows how does penning ion source works. I mean how could ions exit the holes but electrons can't exit. I didn't find any explanation about it on the web

Hello there, I want to solve the heat PDE in a 1D domain for a source moving at constant speed. The problem has been solved already, the solution being stationary in a reference frame moving with the source. This is highly un-intuitive, and I suppose the result originate from the fact the...

Is the answer correct?

Homework Statement Hello guys! Now this is not a homework question, but it may sound like one. If a uniform sized and massed sphere was spinning in space away from any source of forces that could affect it, wouldn't the only forces that act on it are the centripetal and centrifugal? And if...

Hello, everyone, I have to design a constant current source for NTC, to have a more precise measurement. The NTC resistance used range is 1kΩ~13kΩ. I have tried several circuits, but the problem is the the current is not precise enough even in simulation. 1uA difference All the...

I'm still not very confident in analyzing circuits. Here's what I know: 1) v_o=v_IN - v_T 2) id=k/2*(v_IN-v_T)^2 3) v_o=v_S-(k/2)(v_IN-v_T)^2*RS 4) v_o = v_S-id*Rs iDS = v_o/RS The answer I chose in the photo was based off of other online discussions. I'm very confused and don't have the...

Homework Statement Homework Equations Anyone Know why If an ideal voltage source and an ideal current source are connected in parallel, then the combination has exactly the same properties as a voltage source alone? and If an ideal voltage source and an ideal current source are...

Does anyone out there know of a US based source or distributor for high capacity lithium batteries? 100Ah, 200Ah? 3 - 3.2 volts Everything I am finding is China, and the shipping is just outrageous. Thanks, pud

If Neutron stars are what they are... I mean made of literally only neutrons ...how do they generate such immense magnetic field (of the order 10^8 or something) .. I think the name is somewhat misleading and it ought to have a near half ratio of protons ...But still being so compact how...

This circuit is really confusing me. I'm trying to find i using KVL and KCL. What's throwing me off is the short circuit effectively created by the inductor. I know that the whole circuit can't be short circuited because there is a current source that is preventing all of i from going through...

1. What is the difference between non-ideal voltage and non-ideal current source ( not in terms of circuit diagram like ideal voltage source plus series resistance )? 2. And how to decide that which source is used where and when ? ( because output of both is not constant)

Solve i_x when a=2. (See attached picture) This is my attempt (mesh current analysis): I made i1 be the lower left loop current. I made i2 be the lower right loop current. I made i3 be the upper loop current. Mesh1: i1 = 2ix Mesh2: -10 + 3(i2-i3) + 20i2 = 0 Mesh3: -5 + 3(i3 -...

Homework Statement For the circuit shown in Figure, find the equivalent resistance seen by the source. How much power is delivered by the source? http://sphotos-b.xx.fbcdn.net/hphotos-snc7/304377_496325960386924_988412599_n.jpg Homework Equations Req = R1R2 / R1+ R2 P = V^2 / R Thanks you...

I am using An Introduction to numerical linear algebra by Charles Cullen and I'm not very satisfied with it. Kindly suggest me some alternatives. Also suggest good linear algebra book to clear up basics. finally also suggest any online study materials, lecture notes, videos regarding the...

Homework Statement A girl 5 feet tall is running at the rate of 12 feet/second and passes under a street light 20 feet above the ground. Find how rapidly the length of her shadow is increasing when she is 20 feet past the base of the street light. The Attempt at a Solution I let the distance...

Homework Statement This problem has two parts, so I might as well inquire about both. https://www.edx.org/static/content-mit-6002x/images/circuits/H4P3%20Thevenin.2b9528ba9f62.png The figure above shows a circuit with a linear current-controlled-voltage-source and its Thevenin...

I've been given the following problem (attached), not sure how to tackle this one, do I use mesh/node analysis and super node analysis, or can I find the v in the loop with the dependant voltage source then use that as the supply to the second and third loops? Not sure, any help would be...

Turning FETs "off" in presence of AC signal at Drain or Source Hello, I have a very interesting problem that surprised me, and as of yet have not been able to find a solution for. I have two coupled coils. One is being driven by a pulses. The other coil has FET switches to switch the...

Homework Statement Basically, I'm having trouble doing the source transformation and subsequently finding the norton equivalent for this circuit and I don't really know where to start. The circuit is attached where: i=3A V=90V Please help!

Is the local propagation of an entity at invariant speed a sufficient condition for its stress-energy tensor, independently of its explicit mathematical form, to be trace-free, or to have null covariant divergence, or both in curved space-time? In the book “An Introduction To Mechanics”, by...

Homework Statement Determine the voltage across the 2A current source Homework Equations kirchhoff voltage law (kvl) kirchhoff current law (kcl) ohm's law The Attempt at a Solution I'm new to the concept of a current source. I'm not sure how there can be voltage drop across the...