Source Definition and 1000 Threads

Homework Statement What is the photon flux (photons/ m2 s) at a distance of 1 km from a light source emitting 50W of radiation in the visible domain, with wavelength 6000 Angstroms. Homework Equations The Attempt at a Solution Energy of one photon = hc/λ = 3.32 x 10-19J. So, number...

If we have a circuit (see attached) will our voltage source's supplied voltage be delayed by the capacitor in anyway? (as the voltage across a capacitor lags the current through a capacitor by 90 degrees) then, as the resistor,voltage source, and capacitor are all in parallel does this cause the...

Homework Statement Homework Equations The Attempt at a Solution

Homework Statement I am a bit confused on why they can just randomly short the 4kΩ resistor, as you can see from the first pic to the second pic. THanks Homework Equations The Attempt at a Solution

Homework Statement Use source transformation to find the Thevenin equivalent circuit with respect to terminals, a, b. Homework Equations Voltage Division: (V in)*(R1/R1+R2) Thevenin / Norton / source transformation procedures RTh = RNo VTh = INo*RNo Polar...

Hi! I was doing some exercises about the doppler effect on sound until I found this problem that I can't find the solution! "A source of sound of frequency f0 moves horizontally at constant speed u in the x direction at a distance h above the ground. An observer is situated on the ground at...

In the full wave centre tap rectifier, piv of diode require is twice of the input current of the transformer. I can't understand why is it twice when the source is only 1V-peak.

Hello Dear Fellows! We all know that light is an electromagnetic wave and also we know that an antenna receives EM waves and convert it into electrical energy. My question is that is it possible for any specially design antenna to receive Light as a source of EM waves...

Homework Statement Find Vout at t=0.782s (I already found Vout at t=0 s. It is 0 V.) Homework Equations V=IRThe Attempt at a Solution First I found Vs = 9*sin(14*0.782)=-8.989817V (with t in radians) Since Rpi is in parallel with the Vs, its voltage Vpi also equals to -8.98917 V. Since the...

Homework Statement R=50Ω L=5H C=1/125F vs=200.[1+u(t)] V Find i(t) Homework Equations The Attempt at a Solution Write the KCL equation -vs+Ri+L.i'+1/C.∫idt=0 Do the derivation to get rid of the integral, replace all possibly values, we got: i''+10i'+25i=1/5.vs' (*) solve...

Is the laser perfect monochromatic light source?

Homework Statement 2 point sources 20cm apart produce 3 cm waves at a rate of 8 waves every 1.2 secondsHomework Equations how many nodal lines are present what is the angular deviation of the 3rd nodal line? what is the angle between the 3rd nodal line and the 5th nodal line? The Attempt at a...

I do not know how to approach this. I am trying to use r1 - r2 = mλ but I can't seem to find the answer! please help. I figured it out that it is constructive, but i just don't know how to mathematically prove it. r1 - r2 = mλ.

Hi, I currently have a black body calibration source which I use for work. It works great, I can calibrate all the IR thermometers just fine, however it isn't a simple quick "check". The IR thermometers are the ratio type in that they measure two wavelengths and using the ratio it can work out...

Homework Statement Solve for the flux distribution using the 1D neutron diffusion equation in a finite sphere for a uniformly distributed source emitting S0 neutrons/cc-sec. My problem right now is that I can't figure out the boundary conditions for this problem. We usually work with...

My company uses MS TFS for source controlling and I find this really difficult because we have to code on VMs (log on VMs and handle the code in TFS). I would like to make a suggestion to change this into SVN using command line or Tortoise GUI tools. But the client seems not to let publicly seen...

Homework Statement determine thevenin equivalent of circuit at terminals (a,b): Homework Equations Z(L)=jwL Z(C)=-j/wC V(th)=V(oc) R(th)=V(ex)/I(ex) The Attempt at a Solution actually 1st i need help with finding V(th). i do know that V(th) would be the voltage across the 2ohm resistor, so...

Hi I want to define an Am-Be source in MCNPX 2.6 I have Neutron spectrum But I don't have Gamma spectrum of this source. Please Help!

I know that the quasar is a huge source of energy, it can produce energy and light more that glaxies do ; so the question is how that can be possible and the quasar is a super massive Black hole which absorb every thing even Light couldn't escape ?! My Friend tell me when the Black Hole is...

Since friction is a "force" and is able to stop a moving object, why doesn't it possesses energy? For example, light, which is an electromagnetic wave, is emitted from a source which have the energy to "do light". Then what is the source of friction? An object cannot just intrinsically...

Homework Statement Homework Equations P = 1/2 Vm*Im*cos(θv - θi) The Attempt at a Solution First I added all the impedance values to find the total impedance seen by the source. Zt = j10 + (50 || 20 + j10) = 15 +j5 Ω Now since the circuit is not purely resistive, I can't...

Homework Statement A typical incandescent light bulb emits ~3x10^18 visible-light photons per second. Your eye, when it is fully dark adapted, can barely see the light from an incandescent light bulb 10 km away. How many photons per second are incident at the image point on your retina...

Is a resistor a voltage-controlled current source? WHY? I think it is but I don't know whether I'm correct.

Dear forum members, I am trying to solve the following system of equations. ψ(x,y,z)=∫∫ψ(x',y',z)K(x',y',z)dx'dy' z=f(ψ) What I do is to solve the integral equation with a Monte Carlo method, evaluate "z" and do a loop until convergence. My question to you is whether it is...

Hi everyone, As I was doing some research on nuclear energy moratorium, I came across the Bulletin of the Atomic Scientists Journal . After reading some of their articles, I realized that they have a very negative view on nuclear energy. I do not completely trust the source but I would like...

Homework Statement Homework Equations The Attempt at a Solution First, I found all the impedance values. (starting from the left) Z1 = 1 / (j * 16E5 * 15E-9) = -j41.67 Z2 = 80 Z3 = 30 Z4 = j * 16E5 * 60E-6 = j96 I then combined Z1 and Z2. Z1 || Z2 = (-j41.67 * 80) /...

Guess the source of this headline. No search engines allowed! Are secret overseas tax havens essential to the world economy or a benefit to the rich that should be more tightly regulated?

I was having trouble while thinking about the unreal source for refreaction through a lense... In lense light is refracted twice...the real image for the first refraction works as an unreal source for the second refraction... I understand how it is... But fail to feel it... I mean how would I...

Homework Statement http://www.mediafire.com/view/?3efd7326e49kteb I've worked out all except part (iv). These are my workings : http://www.mediafire.com/view/?elswc5g5412zhzq I just can't see how to get rid of cos(pi*(x1+x2/λ -wt). Also, where does the I0 come from ?

Homework Statement http://www.mediafire.com/view/?09c89b8986u5zls The above is a question from my problem sheet. I've got no idea how to attack this since its been very poorly explained in my lecture handouts. Can someone please help me ?

Homework Statement If an average power of 500W is dissipated in the 20Ω resistor, find Vrms, I S RMS, the power factor seen by the source, and the magnitude of VS (Based on circuit in attached diagram) Homework Equations Pave= Irms*Vrms*pf*\frac{1}{2} Imaginary number referred to as...

In the paper "A Mathematical theory of Communication" by Shannon I couldn't understand a theorem (Theorem 4) under the topic "The Entropy of Information Source"- Here 'H' is the entropy. Can you explain me how we get this theorem? What is this n(q)? I couldn't understand the sentence...

hello, in MTW Ex 19.1, it was considered a Weakly gravitating body whereas in Ex 19.3, a Stationary relativistic source. What relativistic means here ? does it mean the source is very dense and massive ? or does it mean it is rotating at near the speed of light ? Can I specify the mass as the...

Hi all, Is it possible to find the direction of a source in 4 quadrants using directional antenna? I am thinking of setting up 4 directional antennas, facing to 4 quadrants, and they will receive the waves from the according quadrants. What do you guys think about this? And is there any...

An electron and a positron annihilate and energy is released in the form of quantized EM (gamma etc.) rays: Now some childish yet inquisitive questions; 1. Where were there quanta prior to annihilation, inside the electron or positron (or both)? 2. Were these quanta really present...

Hi guys. I am having some issue and would love any help. I have a project that requires 30 motors to be hooked up to a single power source. The problem is, the surge voltage that happens the moment the motor turns on causes the buildings circuit breaker to trip. The only way to bypass this...

iam using atmega 32 and i want to use external 16MHZ crystal I have figured out the fuse setting for this as lowbuyte=0xFF and highbyte=0Xc9 what i cannot understand is should i set fuse bits before programming or after programming? because as i have specified external crystal as clock source...

I have an unidentified radiation source. I used a NaI(Tl) detector and multichannel analyzer to collect data and plotted the spectrum. I found peaks at energies of 86.3, 123.7, and 369.6 keV. From this data I am attempting to identify the source, but I am having a difficult time. I tried using...

Is MinutePhysics (youtube) a reliable source? I've been watching his videos since they started, but some of the stuff he mentions I question, or is Physics so amazing that I can't believe it xD?

Hello, for the Poisson problem Δu = -1 on a 2D circular disk with u = 0 on the boundary, we have average(u) = \frac{1}{8\pi}Area(disk), which is easy to see, as the solution is quadratic in the polar coordinate r. Does this (or a similar) relation hold for non-circular 2D domains? This...

Homework Statement I uploaded the assignment it is problem 2 Homework Equations The Attempt at a Solution I really just want confirmation that my work is ok, and the command for a dependent current source in PSpice. The things that I found that are dependent, are very confusing...

FIRST OFF: Sorry for the multiple post on this subject, I couldn't figure out how to edit my first post on this topic (I promise I'm not spamming!) Homework Statement Homework Equations The Attempt at a Solution Step 1: Removed unnecessary resistors R1 and R3. R1 is removed...

I was just wondering if a person wearing convex lenses looks at a light source... Will excess heat be generated in his eyes? As it is a converging lens.. Thanks!

I'm Rich! "New Energy Source"! Tonight I found a very professional looking, 200+ page report lying on my back doorstep. It was a in a folder titled, "New Energy Source", and included the name, phone number, and email address of the person responsible. I have no idea who this person is, why they...

I have an idea for an experiment to see how the distribution of photons changes when they are emitted from a moving photon source. This is a continuation of an earlier discussion here with added information and more questions. "What happens to a photon wave packet when half out of a moving...

Hey everyone! I am designing an experimental, manned aircraft that uses twin caged propellors for VTOL, and I'm looking for a lightweight, high-output power source to power them. Any ideas?

I'm trying to understand the nature of the virtual particles that exists in empty space. I understand that they 'bubble' in and out of existence, but why do they exist in the vacuum of space? If all particles spend some of their time as virtual particles, does quantum mechanics suggest that some...

Homework Statement http://imageshack.us/a/img834/5512/homeworkprobsg216.jpg Using superposition, find i.Homework Equations V = IR, KVL, KCL, Nodal / Mesh analysis, voltage division, current divisionSuperposition procedureThe Attempt at a Solution So this time the dependent source is a...

Homework Statement Find i1 in the following figure, given: Vs=10V, I=1A, R1=5, R2=2, R3=4 Homework Equations KVL The Attempt at a Solution Applying KVL to mesh 1: Vs-i1R1-(i1-i2)R3=0 and i2=I=1A So, i1=(Vs+i2R3)/(R1+R3)=(10+1*4)/(5+4)=14/9=1.56 A But book gives answer as...

Homework Statement http://imageshack.us/a/img831/2617/homeworkprobsg213.jpg Find the load RL that will result in maximum power delivered to the load of the circuit. Also determine Pmax deliveredHomework Equations V = IR, KVL, KCL, voltage division, current division Thevenin procedures,Pmax...