Source Definition and 1000 Threads

  1. A

    Why is a magnet not an infinite source of energy?

    Hi Guys Could someone please point out where I'm going wrong with the following problem. If I place a magnet on a vertical surface such that the magnet must resit the force of gravity in order to hold itself in place, will this magnet stay in place forever? If it does why does this not...
  2. dwn

    Engineering Solving a Node Analysis Problem with 0.632V Voltage Source

    Homework Statement Attached image Using node analysis: ix(0-) = (v-4)/10 + v/3 + v/5 = 0 v = 0.632 ix(0-) = -v/3 = -0.211 A I don't understand why they didn't use a current divider since there is a 5 ohm resistor in parallel with the 3 ohm. Current changes for resistors that...
  3. J

    Calculating Current Supplied by Voltage Source (Complex algebra)

    I've attached the question that I am referring to. I believe I'm heading in the right direction with this one by stating that: 1/Rt = 1/(6+j8)Ω + 1/(9-j12)Ω But I am confusing myself with my algebra. Any help is appreciated
  4. dwn

    Parallel RC with current source

    Homework Statement See images In the first image, I made a circuit with the switch closed and then two when the switch is opened. The bottom circuit is the Thev transform. Homework Equations The Attempt at a Solution Let me first explain my understanding of the circuit. Prior to t = 0, the...
  5. dwn

    Engineering Analyzing source free RLC circuit

    Homework Statement Attached an image with the exact question. Homework Equations α = 1/2RC ω = 1/√(LC) α > ω i(t) = Aest + Bect The Attempt at a Solution (a) First I found ω and α ---- ω = 1.4*10^5 1.4*10^5 < 1/2RC → R > 357.1429 Is it safe to assume...
  6. K

    Issues with Voltage Controlled Current Source

    Good afternoon PhysicsForums! I have a design for a voltage controlled current source. I've included the circuit diagram. The basics of the design is that I have an AC voltage and a DC Voltage summed then passed through a 1MOhm resistor to give me a current on the order of 1 microAmp. This of...
  7. L

    Phase angle between peak source voltage and peak voltage across RLC?

    Homework Statement An LRC series circuit with R = 200Ω , L = 31mH , and C = 1.8μF is powered by an ac voltage source of peak voltage V0 = 540V and frequency f = 550Hz. What are the peak voltages across the inductor, capacitor, and resistor and their phase angles relative to the source...
  8. K

    Adding a 3rd Source to a 2 Source Interference Pattern

    http://imageshack.com/a/img834/5921/7iap.jpg Homework Statement Consider the double slit pattern shown above where the distance between slits is d. Each lettered point is labeled according to ΔD, the difference in distances from the slits to that point. ΔD is expressed in terms of wavelength...
  9. A

    Is it possible? A voltage source with zero output short ckt current?

    That 2 terminals shows PD of 1 volt on Meter, but when shorted, there is no current shown on Meter? I checked and rechecked [using different meters, wires, AC, DC options and what not], so I see only V measurement, but no I. Is it possible? If so, then what is the use of that PD, when we can't...
  10. F

    Angular Velocity of a source of light

    This is not schoolwork. Imagine that light did not have a constant speed, but behaved in the manner expected from experience. Namely, if the source of the light is rushing toward you, the light will approach you faster; if the source is rushing away from you, the light will approach you slower...
  11. V

    Does it matter if the resistor is on top or below a voltage source

    Does it matter if the resistor is on top or below a voltage source after doing a source transformation? According to this picture from wikipiedia, the resistor is on top of the voltage source: But even if the resistor (Z) was on the other side of the voltage source, it would still be...
  12. C

    What´s the temperature at a given distance from a heat source?

    This is not a homework. My physics training feels like having taken place in another life, so please show mercy :) I would like to know what´s the formula to calculate the temperature at a given distance from a candle. I found this: Thermal Conductivity = heat × distance / (area ×...
  13. G

    How Does Changing Wavelength Affect the Power of a Light Source?

    Homework Statement The WSFM radio station (which broadcasts at 101.7MHz) emits 1.78x10^29 photons per second and has an effective radiated power of 12kW. If the same number of photons were emitted as visible light, what would be the power of the light source? Homework Equations...
  14. dwn

    Engineering Solving Source Transforms: Finding v(out)

    Homework Statement See Image Homework Equations Source Transforms The Attempt at a Solution After having simplified the positive terminal of the op amp, how is this calculated into the overall equation to find v(out)? Also, at the v(out) node, in what respect is the 370Ω resistor...
  15. S

    Constant Current Source Simulation Question

    I found this constant current source circuit over at instructables.com. This circuit calls for 2N5088BU for Q1 and FQP50N06L for M1, but I replaced those parts with 2N2222 for Q1 and PHT6NQ10T for M1 because that's what I have on hand for simulation. I calculated R2 = 0.5/0.125 = 4 ohms, but in...
  16. Y

    Measuring current output from a floating current source

    Hi - I am by no means an EE, so please be aware I may have some fundamental flaws in my knowlege. I have a battery powered isoluation unit that takes some voltage in and provides either a voltage or current source output. I am giving it 1V as an input and according to the conversion ratio...
  17. F

    Source of Energy in a Fission Reaction

    Hello. My teacher and I have had this very intense debate for quite some time now and we need your opinion on this issue. This question is, where does the energy released in a nuclear fission reaction come from? (Please use the terms "nuclear binding energy" and "mass defect") My take on this...
  18. M

    Help understanding current source

    Homework Statement This is a really basic problem, just a closed circuit with a current source and a resistor. We are meant to give the voltage and the current across the resistor in terms of the current from the source and the resistance of the resistor. (From the diagram, express Vr...
  19. P

    Why in Huygens–Fresnel, Point source should be as small as wavelength?

    In Huygens–Fresnel principle, to configure the diffraction pattern after an aperture, we need to consider each point on aperture as a point source of light. I need to make a simulation for diffraction. Here I will need to introduce the size of each point source. my question is why the size of...
  20. V

    Common Source MOSFET Amp problem

    Homework Statement A CS amplifier utilizes a MOSFET with μnCox = 400 μA/V2, W/L = 10, and VA=10v. It is biased at ID=0.2mA and uses RD=6k. Find Rin,AVO,RO Homework Equations VAO= -gm(RD||ro) Ro=RD||r0 The Attempt at a Solution I drew out the equivalent circuit with...
  21. muraii

    Source for Autodidactic Learning of Data Analysis Techniques

    I'm looking for a little crowd-sourced shepherding along the road to a more robust grasp of analytical methods for data munging and summarizing. I completed a BA in mathematics but focused on the pure thread, to the degree undergraduates can be said to focus on anyone vein. I was not a...
  22. N

    Doppler effect, source and receiver in different media

    Hello, For convenience, we can say that a submarine at some depth in sea emits sound wave which refracts from the surface of the sea and is caught by a helicopter at some height above the sea. If we know the speeds of the submarine and the helicopter and the frequency of the emitted wave...
  23. D

    What is the Voltage Compliance Range of a Current Source?

    Thank you for any help that you can offer. Did I answer all of the questions correctly and thoroughly? Can you please find any errors, and point them out to me so that I can fix them? Homework Statement Show that : VB = 1.6V VE = 1.0V IE = 1.0 mA IL = 1.0 mA What is the voltage...
  24. dwn

    Solve Source Transformation Homework: V=3.35V, R=228.19kΩ

    Homework Statement Image Attached Homework Equations Ohm's The Attempt at a Solution Combined the two resistors in series : 250 + 550 = 800 kΩ Source Transformation (Current Source): V = 140,000(2*10^-6)= 0.28 V Combine the voltage sources : 6 - 0.28 = 5.72 V But then I...
  25. N

    Can Open Source Cancer Research by Biohackers Lead to a Cure?

    I have looked around for a group of people who perform cancer research as a kind of open /crowd sourced project. Not paid researchers, but a group of people passionate about science and finding a cure. I have found some resources for this kind of research through organizations like COSMIC but no...
  26. gfd43tg

    Dual op-amp output voltage as function of source

    Homework Statement Find Vo as a function of Vs Homework Equations The Attempt at a Solution My thought process so far is to do KCL and find Vo as a function of Vn2, then Vn2 as a function of Vo1, then Vo1 and Vo as a function of Vn1, then Vn1 as a function of Vs, finally giving me...
  27. gfd43tg

    Op-Amp Current Gain with current source

    Homework Statement Problem #6 on the attachment Homework Equations The Attempt at a Solution I am stuck because if I do KCL at the node above the current source, It seems like all of the current should go back into Rs and none from the current source goes up to Rf
  28. B

    Source for aperture information

    Is anyone able to provide a resource for the proper formulae to use in determining blade dimensions for an aperture mechanism? Free would be best but readily available in a mathematics library is acceptable as well.
  29. S

    Does a TCP packet change source ip when it goes through your router?

    I was wondering, every time I send or receive a TCP packet with an IP header, my local ip, ie. 192.168.1.x is displayed as the source or destination, respectively. Does this get changed as soon as the packet passes through my router, so the source/destination is listed as my external IP address?
  30. gfd43tg

    Thévenin equivalent with dependent source

    Hello, I had read in my textbook that when a dependent source is in a circuit, and you wish to find the thévenin resistance, then the method to solve for the thevenin resistance is to turn off the independent sources and add an external voltage, then find the external current. The external...
  31. Z

    Archived Superposition to solve circuit with dependent source

    Homework Statement Assume that Vs = 10V , R1 = 1.7Ω , and R2 = 0.50Ω. Find the current I in the figure using the superposition principle. Homework Equations Superposition principle KCL, KVL V=IR Current and voltage dividers The Attempt at a Solution I = I' + I'' First replacing the...
  32. R

    Radiant (all wavelength) flux emitted by a light source

    hello If I were to hang a traditional 100W clear glass light bulb from the ceiling, would it radiate 80W (radiant flux), the other 20W lost by air convection/conduction up the wires, or would it radiate closer to 60% or 40% of consumed energy? I can find plenty of figures for the...
  33. A

    MATLAB How to control power source base on load condition in Matlab/simulink

    hi i'm using Matlab/simulink to create a microgrid model which simulate dynamic control of power based on the loads. the loads are changing based on the realtime. I use several voltage sources to power the loads. I would like to be able to turn on/off the generator based on the loads. for...
  34. E

    Dirac Delta source for vectorial equation

    Hello! By manipulating Maxwell's equation, with the potential vector \mathbf{A} and the Lorentz' gauge, one can obtain the following vector wave equation: ∇^2 \mathbf{A}(\mathbf{r}) + k^2 \mathbf{A}(\mathbf{r}) = -\mu \mathbf{J}(\mathbf{r}) The first step for the solution is to consider a...
  35. G

    Mesh Current Analysis with Dependent Voltage Source

    Homework Statement Use the mesh-current method to find the power developed in the dependent voltage source in the circuit in figure (Figure 1) if v = 29V. Homework Equations ∑R in mesh 1 * i_1 - ∑R in common between meshes 1 and 2 * i_2 = v_source in mesh 1 ∑R in mesh 2 * i_2 - ∑R in...
  36. gfd43tg

    Source Superposition: Find Vx, Vx', Vx'', Vx

    Homework Statement Apply the source-superposition method to the circuit below to determine: (a) Vx’, the component of Vx due to the 1 A current source alone. (b) Vx’’, the component of Vx due to the 10 V voltage source alone. (c) Vx’’’ , the component of Vx due to the 3 A current source...
  37. P

    Discovering Photon Flux from UV Source

    Hi! I would like to ask if there is possible to find out the photon flux emitted by a uv source having only the intensity/wavelength spectrum of the source? pp
  38. gfd43tg

    Resistance reduction and source transformation to find voltage

    Homework Statement Use resistance reduction and source transformation to find Vx in the circuit below. All resistance values are in ohms. Homework Equations The Attempt at a Solution For this problem, I know I can combine the 16 Ω resistors, but where I'm having a little trouble...
  39. S

    Mcnp source subroutine linking trouble

    Hi, I have written a source subroutine and I am trying to link it with mcnp6. When I run my input file it says you need a source subroutine. My input file and the source subroutine(written in fortran) are in the same directory. Where do I have to keep the subroutine to link with mcnp? Any help...
  40. C

    Reduce Power Source Sensitivity

    I am currently designing an electronic circuit to detect fluctuations of the geomagnetic field in response to solar activity. One problem I am anticipating however is an over sensitive power source which will respond to thermal fluctuations in the holding room (can’t control room...
  41. B

    Special relativity, light direction and wave source.

    If the speed at which light waves propagate in vacuum is independent both of the motion of the wave source and of the inertial frame of reference of the observer, why isn't the direction? Shouldn't the light travel directly upward from the point of emission and not diagonally, following the...
  42. T

    MHB Heat equation with annoying source term

    Hello to everyone, I urgently need to solve the following pde: ∂u/∂t +∂²u/∂x² = So*δ(x-xo)*sin(wo*t) It's the heat equation with a cyclic source. The lentgh of the cable is L. I have no clue how to do this with such a source, all i have learned was to do a separation of variables, but it...
  43. A

    Absorption of radiation from a 'cooler' source

    This post specifically queries the absorption, by matter, of (thermal) radiation which has been emitted from a source of a cooler temperature than the receiving matter. As I understand it, when matter 'receives' radiation, that radiation is either a) absorbed, b) reflected (or absorbed and...
  44. F

    Is the speed of a wave dependent on the speed of the source?

    So, I am reading my Modern Physics textbook (Tipler & Llewellyn), in the chapter on relativity. In discussing the Michelson-Morley experiment, the book states, "The speed of the waves depends on the properties of the medium and is derived relative to the medium. For example, the speed of sound...
  45. PeteyCoco

    Electromagnetic wave emission after source vanishes

    I'm reading about electromagnetic waves and I can't make sense of their self-sustaining nature. If a charge accelerates for a moment and then stops a disturbance in the electric field is sent out. This changing electric field creates a changing magnetic field and they continue to sustain each...
  46. J

    Gravity - use it as an energy source?

    Gravity -- use it as an energy source? If gravity is a force, why can't we use it as an energy source?
  47. J

    Exploring the Age of Light: From Source A to Destination C

    Legend: A is the source B is the photons/light C is the destination (which isn't fixed) c is obviously the speed of light Yesterday I was sat thinking about how visible light can be older than the universe itself. I came to the conclusion that the...
  48. Q

    Assuming only rest mass as source of gravity and real observations

    If we use only rest mass as the source of gravity, but use the rest of general relativity. What are the differences with observations. Excluding cosmology and dark energy. I mean real observations, not just theory. I exclude from the question, cosmology, dark matter and dark energy. In my...
  49. Q

    What is intuitively the source of the gravitational field?

    In general relativity, the source of the gravitational field is the "stress-energy tensor" I know that thing is not just energy. Can some one explain what this quantity is? It's just a 'thing' that just happens to work mathematically and means nothing else?
  50. E

    Ferrofluid in High Voltage AC Source

    What will happen in a ferrofluid in an elastic cylindrical tank when subjected to high voltage alternating current? Is it will expand and then back to its normal dimension periodically because of repulsion? The diagram on the attachment is the set-up, all answer will be appreciated. Thanks
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