Source Definition and 1000 Threads

Hi All, I have read articles and watched videos demonstrating and explaining the basics of Schlieren photography but one point that I am not at all clear on is why a point light source is needed. Can anyone offer a general explanation or point me to a basic illustration that might explain...

Homework Statement Investigating the effect of mass on the period of oscillation. This experiment is about SHM of a floating cylinder, and the theory is explained in this website: http://physics.stackexchange.com/questions/64154/shm-of-floating-objects Also, I'm attaching a diagram of my...

If we connect a single resistor in the circuit of ideal voltage source then what'll be its total resistance? ? Isn't it zero? As shown in image .so is it possible that the total resistance of a circuit is 0 Although it has 5ohm resistor!?

Homework Statement As you drive at a speed of 15.0 m/s an ambulance approaches you from behind with its siren blaring at a frequency of 1022 Hz. After the ambulance has passed you the signal is now 981 Hz. If both you and the ambulance travel at a constant speed how fast was the ambulance...

Does anyone know of a good source for Neodymium Magnets I tried Magnets 4 less but the website seems to be not working.

Does the magnetic component of light emitted by an antenna arise from the effects of length contractions or from the fundamental magnetic moment of the electron?

Hey guys, The following formula is provided on the wikipedia page for downforce, D=0.5(WS)*H*alpha*F*rho*V^2 Where: D is downforce in Newtons WS is wingspan in metres H is height in metres \alpha is angle of attack F is lift coefficient rho, ρ, is air density in kg/m³ V is velocity in m/s...

I've recently been told by my mentor that the source for all energy is the Sun, which makes sense if were talking about chemical energy in photosynthesis, solar energy, etc. However, if we think about a meteorite which is due to hit the earth, surely we cannot say it got its energy from the Sun...

We see always in source meter machines a LED which indicates the limit current. I want to know what is the limit current and what is the relationship between this later and the resistivity.

Here is the circuit. I have to find the voltage across each resistor and the current i1 and i2. My attempts are the following: By KCL, i2 + i1 = 0.1 A By KVL, 3 - 5 - 100i1 + 1100i2 = 0 ∴ i1 = 0.09 A, i2 = 0.01A ∴ Voltage across 100Ω resistor = 0.09 × 100 = 9 V, voltage across 1100Ω resistor...

This is a problem from Foundations of Analog and Digital Electronic Circuits by Agarwal & Lang, I'm going through it by myself, I'm not in a course, so I'm depending on you friendly forum people for help! I really like this book but it has a lot of errors, perhaps this is another error. 1...

Homework Statement So in my textbook it says "The speed of the wave depends on properties of the medium, not on the motion of source or observer. An explosion causes pressure variations in the air around it. This "deformation" propagates outward as a sound wave at a speed dependent only on...

What is the effect on the interference fringes in Young's Double slit experiment when the source slit is moved closer to the double slit plane? I have seen you people @DrChinese , @Cthugha , @bhobba helping in these kind of topic before. Can you help here? It would be great if others also can help.

What is the best solution of the heat equation that described a transmission of heat from a source kept at certain temperature to a reservoir with an initial constant temperature (lower than the source) where its ends are not insulated from the surroundings and the surrounding is kept at a fixed...

Hello, There is an omni-directional and coherent light source rotating at the frequency of EM waves. If you think of the wave model, there will be nothing unexpected that you can imagine the space is rotating around the source. However, if it is quantized I can't tell what happens since photons...

When a quite big star consumes its fuel, it explodes with supernovae. So, if it consumes almost all of its fuel up to the iron, then how can the new stars born after explosion. I mean, Hydrogens already turned into Helium and Helium into Carbon and so on. Does star consume all the fuel it has or...

Homework Statement Compute all the currents labeled using the mesh loop method. Homework Equations Parallel Resistors 1/Rt=1/R1+1/R2...+1/Ri Series Resistors R1+R2...+Ri The Attempt at a Solution My attempt at the kvl and kcl analysis, I think I did this wrong because I can't solve for...

Homework Statement A sound source has frequency 1000Hz and moves at velocity v along a straight line. A person stands a perpendicular distance d away from the line. At time t=0 the source is at its distance of closest approach to the listener. Express the frequency as heard by the listener as a...

Homework Statement I performed a lab with a simple DC circuit. The circuit has 4 resistors (i.e. R1, R2, R3 and R4), which is the same as shown in the attached image. When the voltages across all resistors were added, they were higher than the source. How is this possible? The KVL rule states...

Homework Statement http://oi57.tinypic.com/263tqvr.jpg I decided to try using mesh currents for thisFirst mesh is IA, second IB, third, ICSo I have the equations IA = 500 μA 1310 IB + 100(IA - IB) = - 4*10-5V2 IC = -80IBAre these equations correct so far? I get the feeling they're not

Homework Statement A small source emits sound waves with a power output 80W. a) find the intensity at a point 3.0m from the source. (0.71W/m) b) find the intensity level at the same point as part a.(118.51) c) at what distance would the intensity be one-fourth as much as of that part (a). i...

Homework Statement This diode zener has breakdown voltage equal to Vz=8.2V for currents: 75mA<=iz<=1A.If RL=9 Ω,how much must Rs be,so that VL=Vz=8.2V,while Vb changes at about _+10% in relation with the nomimal operating current,displayed in the data sheet which is 12V? The Attempt at a...

Homework Statement http://i62.tinypic.com/245fwxu.jpg[/B]Homework Equations & Attempt to solve [/B] http://i62.tinypic.com/142v6mv.jpg Bottom: A Top left: B Top Right: C(1/100 + 1/5 + 1/25)VB - (1/25)VC + 6.25I = 450 mA (20.8)VB - 0.04 VC + 6.25I = .450 A VC = 45 + 6.25I I know I'm doing...

Homework Statement Find V0 using voltage/current division Homework Equations V=(VsR)/Req I=(IsIeq)/I The Attempt at a Solution I used general circuit rules (parallel and series) to get the total resistance as 14.775 ohms{?}. And I'm stuck with what to do next . . .

Homework Statement Homework Equations V=IR P=I^2 R[/B]The Attempt at a Solution [/B] What does it mean physically and intuitively "power entering the source" ? That might be a start in getting me to understand why the answer is just negative the power dissipated in the resistance. What...

Homework Statement A voltage source connected to a circuit produces a voltage V, current I and has internal resistance R. What is the new voltage if an identical voltage source is added to the original: a) in parallel b) in series Homework Equations V=IR[/B]The Attempt at a Solution a...

Homework Statement Hi, I already asked a question close to this, but now I have different conditions. This is the circuit C_1 = C_2 \\ R_1= R_2 The current is an AC , and I would like to know the voltage at R_1 and at R_2 I made some progress but I do not really know hot to continue...

hello I solve neutron diff eq for plane source in the vicinity of slab of water but if i substitute source term with 1 the flux in some places is greater than one! how it possible?! i am sure about my calculation so someone say me how it possible?

sir, i am looking for fixed DC (110VDC and 220VDC) from my variable AC source (0 to 220V). please support me. rajesh.p 9010770003.

Hi I am studying entropy and I am new to the concept I don't know where to start in this question: State the maximum entropy of a 16-symbol source. thank you

Okay, so I'm new to this forum, but I'm hoping I can get some help. I live in the United States, and I'm having trouble converting from metric to standard with the build plans given. I want to build the open source Spaceframe recumbent bike which the build plans can be found...

Hi.i know that a ideal current source has infinite resistance and it supply's constant current to aload connected across it. The current source doesn't have the infinite resistance in series to it but in pparalle. All is well until I think of this Norton's Therom. When we transform a voltage...

The energy of photon is $$E=\frac{hc}{\lambda}$$ Now if we have an isotropic point light source of power P, Number of photons $$N=\frac{P}{E} = \frac{P \lambda}{hc}$$ Hence one can find the change in momentum and hence the force exerted by a beam or light sources. But let's say we keep an...

Homework Statement I am supposed to give a thevenin equivalent circuit to the one posted in the picture. Homework Equations V=IR KVL: "voltage drops around a closed loop sums to zero KCL: "current into a node equals current out of a node" The Attempt at a Solution The part I'm confused...

Homework Statement Which of the following are self-contradictory combinations of circuit elements? - A 2 Amp current source in parallel with a short circuit. Homework Equations KVL- "the sum of voltages around a closed loop amounts to 0. KCL- "the current into a node equals the current out...

Hello. This is a question for the philosophers. I know just a little bit about QT and GR, but have a solid background in QM, classical physics and some particle physics. I was wondering about the stress energy tensor. I know that the graviton must have spin 2 because the source of gravity is a...

Homework Statement I was able to find the Thevenin equivalent between ##A## and ##B## using loop analysis and then Ohm's law: The Thevenin equivalent was ##V_{th} = -4.0 V## in series with ##R_{th} = 0.8 k##. Now I had a question about solving the problem using a different approach. I...

Homework Statement I have a PDE and I need to solve it in spherical domain: $$\frac{dF(r,t)}{dt}=\alpha \frac{1}{r^2} \frac{d}{dr} r^2 \frac{dF(r,t)}{dr} +g(r,t) $$ I have BC's: $$ \frac{dF}{dr} = 0, r =0$$ $$ \frac{dF}{dr} = 0, r =R$$ Homework Equations So, in spherical coord. First...

I am working on an input file in MCNPX/6 that uses a CT scan lattice geometry. I want to specify a small source in a large universe (lung). Right now I have a source uniformly distributed through the universe. The existing documentation is vague on this topic. Is it possible to contain the...

The question is to solve the current through a resistor after a pn junction. (photo attached) As far as I'm aware the voltage source in the pn junction is (in this orientation) of opposite polarity to that of the 0.8V voltage source. From my understanding the answer goes like: V=IR I=V/R...

I have created a macro file that should produce a Gaussian (Normal) distribution of gamma particles ranging in energy from 0 to 250 keV as follows: /control/verbose 0 /run/verbose 0 /tracking/verbose 0 /gps/particle gamma /gps/ene/type Gauss /gps/ene/min 0 keV /gps/ene/max 250 keV /run/beamOn...

< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > I have taken part in a competition about solar car racing recently. The car I am going to make is just as big as a toy car. I have some problems about it's power source. I am going to use...

This is probably a simple matter. I have tried to find an answer on the web without success. All published data on current-limiting resistor values is for LEDs with current rating less than power source. I am putting together an array for a museum of high brightness LEDs rated at VF 4.2, IFM...

I know that van de graaff generator is a high voltage generator, i was wondering though if we can use it as a current source, if we get any resistor, connect the negative terminal to the generator "if the generator generates negative charge " then ground the positive terminal, then any charge...

St. Elmo's fires produce light and therefore useful energy. https://en.wikipedia.org/wiki/St._Elmo%27s_fire#Cause What is the source of this energy? I mean from which to which form does it convert to?

Hey guys, i did this source transformation as an alternate method to find the transfer function of a circuit, however I am getting a different transfer function of 2/(2s+(s+3)(s^2+1)) to the solution in the following image. Any help would be really appreciated :)

It's question 1b) Please view attached 1. Just to clarify, when different voltage sources are in series you pick the smaller one? 2. First step, they turned the 1A and 2ohm into 2V, why does the resistance disappear? Then between the last two steps the 12/7 ohm resistance remains with 18/7...

Hi guys, I've seen a lot of textbooks converting between 2 apparent magnitudes to the ratio of 2 fluxes. But I just want to know how to convert 1 ( ONE, UNO , 1, NOT 2 ) flux to 1 ( ONE, UNO, 1, NOT 2 ) 1 Apparent Magnitude. I think I saw my professor wrote this down, but am not sure . Is this...

Hello guys.I am really having a problem with a circuit that includes a dc source,an ac source,2 resistances and a diode(not ideal).In the pdf that i uploaded is my way of thinking for this.I will really value any help and guidance. Thnx in advance

I had some problems finding out an equivalent way to describe a particular gama source.We can get the original way describing the particular gama source in this file: "1.txt", as well as its model in this file:"model.jpg",with this describing way,we can get the distribution of gama flux like...