Source Definition and 999 Threads

Hi, I am building a charger for my bicycle front and tail light that uses dynamo to charge them while cycling. However, depending on my speed, current is fed differently to lights and they start to flicker. Therefore, I was wandering if there is a way to make a constant current source which...

Small radioactive sources are often used for laboratory experiments. They are enclosed in a metal container with a small window. A gamma source might be covered by a stainless steel window. What would you expect the window of an alpha source to be like, and why? (I know the answer has to do with...

Hello All, Is it possible to analyze signals/photons/pulses from a 57Co source (strength 2 microCi) using a ADC (multihit readout) with 5 GS/sec? Just to look at pulse height spectrum..also I am interested to make a coincidence counting between 122 adn 14.4 keV levels! I heared that these ADCs...

Hi, I'm developing a very simple solar system simulator for educational purpose. I had taken from wikipedia mass, velocity of planet and applied universal gravitation formula and applied to all celestial corps. It works well, but when I add the moon... the moon is like a planet, rotating around...

I am now in the process to define a cubic volumetric source in mcnp code, does anyone have a clear explanation for that.

1. The problem statement, all variables, and given/known data I have a single loop RL circuit with no source. I am given the the inductance of 3mH, as well as that energy storage is as follows 1 J @ t=0 and 100mJ @ t=1ms. No current is given. I have to find R. I don't need the answer just some...

I am looking for joint(s) small enough that I can attach four of them at one point and still have them smaller than 1cm. U-joints would be small enough but may have too much "play". Ball joints probably don't come four at a time. I've looked at a dozen ways I could build such joints from...

I have read that at a balanced three phase AC system reactive power is not tranferred between source and load but instead it is exchanged between system phases. Is this true? I can't find any book or paper that corroborate this

Ok, according to my in depth research, wiki, the filament of standard incandescent light bulb will reach a temperature of roughly 2500 K. According to Stefan-Boltzmann, the power radiated from an object at temperature T (K) is given by P= A ε σ T^4 . Suppose the filament has a radius of 1mm...

Hi everyone, i need help you all to give me the where can i find the source about my project. I need to connect the raspberry Pi 3 to the hdmi switcher. so i can change the from hdmi to another hdmi. what i know, the connection of them need to be used by RS323. In the raspberry pi , i will...

Homework Statement [/B] Derive an expression for vc(t) in the circuit of Figure P4.13 and sketch vc(t) to scale versus. I attached a screen shot of the circuit for this problem. time. Homework Equations V = IR V = V0exp(-t/tau) The Attempt at a Solution [/B] I am trying to find the...

Hi everyone I would love to get some feedback on this silly idea I had when thinking of the balloon analogy. Another way to achieve the same effect - at least in 2 dimensions - is to move a projector further away from a screen - everything expands relatively. If the universe is a 2d hologram...

The source code is as follows: #include <stdio.h> #include <math.h> #define pi 3.14159265 #define nbin 10000 #define small 1.e-12 int addj(int data[nbin],double *tw,double x,double y,double vx,double vy, int xn,int j,double tc); void billiard(int data[nbin],int nx,int nt,double x); void...

I am looking for a source (or several) on advanced EEG design techniques, in particular how the highest quality electrodes are made. I understand the basic principles of how an electrode works but have no knowledge at all about design techniques. Does anyone know of something that would help me...

Is there a central authority or repository for physics equations something like the International Bureau of Weights and Measures but for formulas? The reason for my question is if I find a stock physics equation in a textbook that is incorrect and I want to see if it is incorrect everywhere...

Hello, everyone! When thinking about an issue pertaining to a work of fiction, does the "primary vs secondary sources" rules matter when coming to a conclusion? Does this wildly held belief hold up in the world of fiction where things are up for interpretation? An example would be, at the end...

Does anyone know what the open source code is called that hysys was built on so I can file a freedom of information act paper work. I would also like to do this for NEC-2 for antenna radiation modeling.

Hi everyone, I've been looking at a problem that seems simple at first, but appears to be deceptively difficult (unless I'm missing something). 1. Homework Statement I've been looking at a problem that involves the diffusion of a scalar quantity, ##q(x)##, on the semi-infinite domain, ##\leq...

1. For the circuit shown in (Figure 1) , where V= 2.8 cos(2 t+ 0.3 ) , R= 8 Ω and C= 4×10−2 F , find the average power supplied by the source, Ps and the average power absorbed by the resistor PR .2. p (t) = v(t)i(t) = VmIm cos (ωt + θv) cos (ωt + θi) PR = (1/2)(V2m/R)3. From the...

It has been demonstrated that it is possible to make humans hear sounds using waves. Abstract From Journal of Applied Physiology Is there a practical method for shielding? I mean using materials for simple attenuation, and/or altering characteristics of waves (frequency, phase and/or amplitude).

Homework Statement A voltage source E_0 cos ωt is connected in series with a resistor R and a capacitor C. Write down the differential equation expressing Kirchhoff’s law. Then guess an exponential form for the current, and take the real part of your solution to find the actual current...

Homework Statement Homework EquationsThe Attempt at a Solution (a) [/B]We can assume for ideal op-amps that there is: infinite input impedance low output impedance the potential for infinite amplification (b) Non-inverting op amp (c) This is the part I have trouble with. There is three...

Homework Statement Here i am asked to find the phase difference. Homework EquationsThe Attempt at a Solution I know that usually the equation is mλ=asinΘ

In X-ray diffraction, during the experiment a X-ray beam will create an incident and diffracted beam, but what exactly is the virtual source? I may be mistaken but isn't the source the incident beam, in the attached image, it seems to suggest otherwise?

My question is that in Michelson Morley experiment, how they produced the light? what was the light source and has anyone used sunlight as a source yet to re-confirm that experiment? I am interested in sunlight as a source of light due to certain reason... Please if you know kindly mention the...

I want to subscribe to a reputable news source (even if I have to pay). I want a news source that has not abandoned journalistic integrity. I'll still keep my current sources of news (Yahoo!, Google news, NPR, BBC, etc.) but I am now -- out of principle if for no other reason -- feeling like I...

I'm currently doing a chemical model of Titan's atmosphere and the simulation outputs several files (up to 1000) and I need to get an array of data out of them from a specific section labeled with a chemical name (i.e HC5N) that has an arbitrary number of values (usually above 100). I've seen...

Homework Statement Find the impedance as seen by the source. Homework EquationsThe Attempt at a Solution -j2||j1 = 2i Z = 2-j1+j2+(1^2)/(j2+2+j2) Ztotal = 2.1+0.8i Is this correct?

Homework Statement Vs = 100cos(2000t) Homework Equations KVL, KCL The Attempt at a Solution My mesh equations are: -Vs + I1(30-12.5j)-I2(120j)=0 4Ix+I2(120j+20)-I1(120j)=0 Ix = (I1-I2) Are these correct? When I solve I get a different result than when I do nodal analysis.

The specific information of secondary neutron source in French 1300MWe and N4 PWRs are needed, e.g.the total mass of Sb-Be in core and the thickness of Sb-Be cladding with stainless steel, but unfornately I couldn't find any useful information in google in English. I guess some informatio could...

Homework Statement The potassium isotope 4219K has a half-life of 12 hr, and disintegrates with the emission of a γ-ray to form the calcium isotope 4220Ca. What other radiation besides γ-rays must be emitted? How many electrons, protons, and neutrons are there in an atom of the calcium isotope...

Dear All, how to know whether electronic components such as spectroscopy amplifier (canberra 1413 or 2010), single channel analyzer (from ortec) and NaI Scintillator counter with its basis are working good. Are there any testing methods using a oscilloscope. I have a Mössbauer radioactive...

Homework Statement A point source of γ-radiation has a half-life of 30 minutes. The initial count rate, recorded by a Geiger counter placed 2.0 m from the source, is 360 s-1. The distance between the counter and the source is altered. After 1.5 hour the count rate recorded is 5 s-1. What is the...

Homework Statement Homework Equations S= 3VaIa* The Attempt at a Solution After transformation: Ia = 120<0 / (6+8j) = 12<-53.13 A Total complex power = 3 * Va * Ia* = 3*120<0 * 12<53.13 = 2592W + j3456 VAR This is the power supplied from source. What would be the power consumed by load?

Homework Statement Find the: -Complex power delivered by source -Power factor of total load -Is the power factor leading, lagging, or in unity?[/B] Homework Equations KVL/KCL The Attempt at a Solution I want to solve this via mesh analysis to get currents. Mesh1: -10V + V1 + 0.75V1 = 0 V1 =...

Homework Statement Homework Equations V=IR The Attempt at a Solution First I combined the -j3 capacitor and 4ohm resistor to get: \frac{32-j48}{25}. Then I combined that with the j4 ohm inductor to get: \frac{32+j52}{25}. Then I combined that with the -j2 ohm capacitor to get...

Hi. To frame things generally, I have a variable indoor light source that shines on an inclined plane. More specifically, I have a 3-D LED matrix that shines light onto a miniature pv array. Essentially, I am using an indoor “sun” to shine on the array. I measure the energy produced, and...

Homework Statement Using the superposition principle, determine the current i(t. 2. Homework Equations Zc = 1/jwC Zl = jwL V = I*R I = V/Z The Attempt at a Solution First, I converted inductor/capacitor to impedance: L = 1.5H -> jwL = j * 10 * 1.5 = 15j C = 10mf = 1/(jwC) =...

I have multiple sources that have a max power output of 60mW, I am using a power meter that can read up to 200mW but when I connect directly to the source channel I get approximately 15mW or less. I have tried a different meter and I have tried different sources only to end up with the same...

Homework Statement I am given this circuit...

Hey everyone... I've tried to solve this problem with all kind of methods ,but I couldn't do it. I have tried to make an open circuit between R2 and R2 and then to find thevenin voltage and Ri but I have problem solving for thevenin voltage because of this dependent current source... Please give...

Homework Statement I have to do nodal analysis and I was wondering if there is any transformations or simplifications I can do to the circuit. In this class we are supposed to be able to look at the circuit and input what we need into the matrix based on just looking at it. I am not sure that I...

[Moderator's Note: Thread moved from forum General Physics hence no formatting template] I am trying to study Circular Motion for my exams and I'm kind of unsure about one question. The question asks what's keeping the truck in circular motion. It has to be gravity I know, but gravity being...

Hello guys so I have this idea of mine which I can't get my head around and I need someone to tell me why it won't work, so let's say you have a fully pressurised tank of air and you blow that pressurised air at a turbine connected to a generator, ovisously the generator will then start to...

Homework Statement Homework Equations V=IR Thevenin/Norton The Attempt at a Solution I am trying to find the Voc, but this circuit isn't making sense to me. So to start we can ignore the 9ohm resistor and that branch for now when Finding Voc so you are basically left with the square...

Homework Statement A point source isotropically emitting 10^8 fast nuetrons per second falls out of its shield onto a railroad platform 3 m horizontally from the track. A train goes by at 60 mph. Ignoring scattering and attenuation, what is the fluence of nuetrons that would strike a passenger...

Homework Statement A 1 meter long uniform line source of high energy photons emits 10^7 photons /sec. Calculate the particle fluence rate (flux density) at a point P 1m away from the midpoint of the source. Homework Equations ## dN = number~of~particles ## ## da = differential~area## ##\Phi =...

Homework Statement A point source of light (wavelength \lambda = 600 \, \text{nm} ) is located a distance x = 10\,\text{m} away from an opaque screen with a small circular hole of radius b. A very small photodiode is moved on an axis from very far away toward the screen. The first...

Hello. I am reviewing the use of the Laplace Transform to do circuit analysis and I am slightly confused about the transform of a constant voltage source. For example, let's say we have a constant voltage source V1(t) applied to a circuit for a long time - let's say it reaches steady state. We...

Here's the amplifier in question: I'm not understanding this part: Why is Cs not included in the current divider ? To my understanding of current divider, It = Id+Io, where It is the current flowing through Rd So, Io = It*(1/Cs)/(1/Cc2)+RL