Transmission Definition and 708 Threads

  1. P

    Best book for Electromagnetic Theory & Transmission Lines

    best book for "Electromagnetic Theory & Transmission Lines" We've this subject of "electromagnetic theory and transmission lines" this semester..and i wanted to know which books deal the content properly ...mastering this topic may require that one cool book (and ofcourse, regular effort)...and...
  2. C

    Understanding the Impedance Conditions in Transmission Line Problems

    hi need some direction on this problem please. see attached file, i decided to type more or less my progress,instead of attaching nonsence !. i had had a few more ideas but no luck. any positive direction would be much appreciated, I've looked back at my textbook (electromagnetics by hayt...
  3. K

    Coaxial Cable ( Transmission line )

    How does current flow in a coaxial cable in each of the following cases : 1. When the cable is connected to a DC voltage source. 2. When the cable is connected to an AC voltage source 3. When the outer metallic shield is connected to ground and DC and Ac sources are connected separately I...
  4. N

    Quarter Wavelength Transmission Line

    An open-ended quarter-wavelength, air-spaced, parallel-wire transmission line is found to be in resonance with an oscillator when its length is 0.25 m. When a capacitance of 1 pF is connected across the open end, it is found that the length of the line must be reduced to 0.125 m to obtain...
  5. D

    Synaptic Transmission & Neuronal Integration

    Homework Statement Hi all, I have to write a couple of essays for a neuroscience course, but I was hoping I could get some clarification regarding the titles just to be sure that my answer is relevant: (1) Describe synaptic transmission with reference to the electrochemical conduction of the...
  6. E

    Transmission lines and Waveguides

    Ok, it's clear to me that waveguides are for sending EM waves from one place to another (e.g. TEM, TE, TM modes). But what about TLs? I've seen them described as carrying AC signals (V or I) but also EM waves, e.g. TEM waves in coax cable. What gives? Does one imply the existence of the...
  7. C

    Transmission Parameters of Single Vertical Resistor

    Hello every body... Consider two port system having a resistor (can it be called two port system?)... ____---->I1________________I2_<----_________...
  8. J

    Thin Film Interference- Transmission

    Homework Statement A thin layer of water (n=1.33) is surrounded by air what wavelength of light will not be transmitted through the water at the point where the water is 113 nm thick? The Attempt at a Solution - In phase - Path difference of 2T. - Constructive Interference I just...
  9. B

    Wireless Network Transmission Through Brick Wall

    Homework Statement A wireless computer network transmits data across the space between nodes as a modulation of a 2.45GHz (microwave) carrier signal. The signal is able to pass through a brick wall that is 100mm thick. Measurements have determined that the dielectric function at microwave...
  10. fluidistic

    Potential barrier in QM problem with coefficient of transmission

    Homework Statement I'll try to recreate from my memory the problem we've been assigned on a test more than one month ago. They gave the solution but I either misunderstood or miscopied it. An electron with kinetic energy 5 eV goes from a region with potential V_0=6 eV (let's call this region...
  11. M

    Power Transmission: How High Voltage/Low Current Works

    From what I have read electrical power is transferred at high voltage and low current in order to reduce energy loss in the form of i^2R. High voltage at low current is the same power as low voltage at high current. My question is how do they do it. If they apply a higher voltage and the...
  12. J

    Maximizing Wired Power Transmission: Resistance, Voltage and Color

    1. Question DC power can be transmitted using a wire over distances of a couple miles. On the contrary, AC power may be transmitted using a wire over much greater distances. a) What physical quantity needs to be minimized to maximize the reach of wired power transmission from a power...
  13. N

    Mutual Conductance formula/computation in transmission line

    Hi all, I am trying to compute the coupling effects or crosstalk in the circuit attached. In MTL (multiconductor transmission line) model of two wire or three wire lines for main lines, how to calculate or simple equation of mutual conductance? which is denoted as g12 in the circuit...
  14. A

    Calculation of capacitance of transmission lines

    Capacitance between two plates is defined as the charge accumulated per unit potential difference between those plates. But in the case of transmission lines how can we define it? The potential difference any two conductors in a group of several conductors can be derived in terms of the charges...
  15. S

    Speed of transmission in quantum entanglement

    speed of "transmission" in quantum entanglement when we "collapse the wave-function" via observing one of the entangled photons: is the transfer of the collapse information instantaneous (to the twin photon) or a few/many orders of magnitude of speed of light? lets say we observe one of the...
  16. N

    Fresnel equations, transmission higher than one?

    Hi, I was wondering how come I can get a transmission coefficient higher than one? In the equation at normal incidence: t = E_t/E_0 = 2*n2/(n1+n2) > 1 if n2 > n1 How is it even possible to get a higher electric field amplitude out compared to the one that got in? I'd be very...
  17. reddvoid

    Pre requisit to study transmission lines and wave guides

    what is pre requisit to study transmission lines and wave guides...? I've studied vector algebra and vector calculus, is it enough or ?
  18. M

    Understanding the Importance of Proper Grounding in Single Wire Transmission

    https://mail.google.com/mail/?ui=2&ik=3313338a72&view=att&th=13350dc1754a8105&attid=0.0&disp=inline&zw Can someone explain why the source must also be hooked up to ground. I know it completes the circuit but what's the point? Why wouldn't current flow without it? Since the line is at a...
  19. I

    Interesting Telescope Image Recording and Transmission Design Problem Need help

    Homework Statement You have been tasked with the design of a new far-field, high resolution imaging system to be placed on the Hubble Space Telescope. This system will be used for taking deep space astronomical images with an exposure adjustable between 10 minutes and 24 hours based on the...
  20. S

    Total Resistance of Transmission Cables

    Homework Statement A mining company use an electric pump with and operating voltage in the range 1.25kV - 1.5kV. There is only a 240 Vrms supply available. A transformer is used to step up the output voltage to 1.5 kVrms. The secondary winding of the transformer has 2000 turns of wire. The...
  21. S

    Quantum Tunnelling - Transmission Probability

    Homework Statement It's not really a given problem, it's more of a section of my lecturing I truly just don't understand. I'm given that the probability of transmission (T) is the ratio of the intensities of the transmitted wave and the incident wave. However, a bunch of math gives also that...
  22. T

    How do transformers affect power transmission in a circuit?

    Homework Statement As attached. Homework Equations - The Attempt at a Solution I think P is a step-up transformer while Q is a step-down transformer. Does the current and/or voltage change during XY? I know the answer is either B or C, but I do not the explanation. Can anyone...
  23. Reshma

    Help with scilab code for calculating transmission coefficient

    I seem to be getting some arbitrary values from my Scilab code for a function. I have to generate a graph showing the dependence of the transmission on the air gap separating two higher refractive index materials i.e. I want to plot "T" as a function of "d". T = \frac{1}{1 + \beta \sinh^2...
  24. A

    Understand Ehv DC Transmission: I2R Losses Explained

    i have read that in high voltage transmission line dc is preffered on ac and i know all advantages and disadvantages but one main disadvantage that i cannot find was I^2*R losses which was the main reason why we use ac on the first place can someone please explain that?
  25. M

    Parallel transmission lines / TL switches

    If i wanted to make a 1:N coaxial RF switch (say ~100MHz, nothing too high), could you simply route N traces in a star pattern on a PCB and implement a mechanical switch to either connect to your measurement point, or terminate in the characteristic impedance (say 50 Ohm). I'm getting thrown...
  26. M

    Inductive coupling & wireless power transmission

    I'm considering a very simple method of powering a small electronic device from a typical current carrying outlet. I'm trying to make a theoretical prediction to the amount of current I could generate using magnetic induction. Problem: I have a straight current wire carrying an...
  27. Y

    How Do We Derive the Transmission Line Equations Using Differential Methods?

    Eqn. (2.1) \frac{\partial v}{\partial z} = -L \frac{\partial i}{\partial t} Eqn. (2.2) \frac{\partial i}{\partial z} = -C \frac{\partial v}{\partial t} Eqn. (2.5) v(z,t)=V^+f(t-\frac{z}{v_p})+V^-f(t+\frac{z}{v_p}) From the book I'm reading: "By substituting Equation (2.5) into Equations...
  28. P

    Transmission Line Impedance Matching

    In the case of a complex source impedance ZS and load impedance ZL, maximum power transfer is obtained when ZS = ZL*. For a lossless transmission line terminated on one end with a purely resistive load, zero reflection is obtained when ZS=ZL. What about the case of a lossy transmission...
  29. T

    Transmission coefficient of spin-1/2 in magnetic field

    Homework Statement A particle of mass m, (nonrelativistic) energy E, spin 1/2 and magnetic moment \mu*\sigma is traveling in the positive x-direction from large negative x. For x > 0, there is a constant magnetic field B in the positive z-direction. There is no field for x < 0. a) Find...
  30. P

    Quantum Transmission Coefficient

    Hello. I have a question, mathematical in nature. Considering a potential step of height V0 and width a, the amplitude coefficient is t=\frac{2k_1k_2e^{-ik_1a}}{2k_1k_2\cos{k_2a}-i(k_1^2+k_2^2)\sin(k_2a)} Now the transmission coefficient is T=|t|^2 So I need to find the absolute value of...
  31. B

    Transfer function of transmission line

    Homework Statement Calculate the output vo(t) if the input is the signal vin(t) shown in attached figures. The Attempt at a Solution I've calculated that ransfer function transmission line: H(s) = Vo(s)/Vin(s) = exp(-j*gamma*l), where gamma = -j*omega*sqrt(LC). However, tau = sqrt(LC)*l...
  32. K

    Three Phase pi-section model of power system transmission lines

    I am using the "Three-Phase PI Section Line" Matlab-Simulink block from Simpowersystems blockset for modelling an electric power system transmission line. I had obtained the data from a research paper regarding the transmission line specifications (provided as sequence values). Since I am...
  33. M

    Power transmission through space

    If we had a source of power in space at some distance is there any feasible way it could be transmitted to the Earth and converted to usable power here? Assume an almost unlimited source that can be converted to anywhere in the EM spectrum so efficiency is desirable but not required. The only...
  34. D

    Why are Transmission Voltages in India Multiples of 11kV?

    why transmission voltages in India are multiples of 11kv?
  35. T

    Understanding Transmission Design: Connecting RPM from Gearbox to Sprocket

    im confused. how do you relate the RPM from gearbox to a sprocket?
  36. A

    Reflection and transmission of signal

    How do I determine what percentage of a signal is reflected and what percentage goes through a wall. I know that I am over simplifying things, but for the purpose of my project I need a simple answer to this problem. What parameters are needed for the solution and how do we calculate this...
  37. S

    Yet another wireless power transmission thread.

    Hi everyone, this is my first post on the forums :redface: OK so I want to design a microwave power transmitter and I need a few opinions before I make any commitments. I haven't made many complex circuits before, but I am going to do my homework if this is viable and break it into chunks...
  38. R

    Emissivity & Thermal Transmission

    Stainless steel has emissivity of 0.12. It means it only absorbs 12% of radiation and reflect the rest of the 88% as well as tranmitting the 12%. Now if you heat the stainless steel to say 300 Celsius. It won't transmit the 300 Celsius but only a little of it. This is why thermal imagers can see...
  39. J

    33kV 3phase fault causing transmission line entanglement

    Good morning Gentlemen (and Ladies), I'm looking for some help from you HV experts out there. I have had an event where it is believed that a flooded transformer connection box induced a fault on to a 33kV 3phase transmission line, and the fault current was enough for the repulsive forces...
  40. SredniVashtar

    Four wires transmission line for data

    I read on Kraus' "Electromagnetics", 4th edition (p 583), that four-wire transmission lines (in a quadrupole configuration - the conductor with the same polarity are in diagonal) improve shielding. + - - + I tried to find some more information about this sort of transmission lines but...
  41. M

    Transmission probability (tunneling) question

    A beam of 11 eV electrons is directed towards a barrier of potential Vo = 3.8 eV. Compute the width of the barrier for which the reflection is maximized (Note: this is NOT asking for when reflection is 100%). Transmission probability for E > Vo: T = [ 1 + (Vo²*sin²(βa))/(4E*(E - Vo)) ]^(-1)...
  42. R

    Wireless music transmission using lasers

    Hey all. I'm currently working on a project where I use a laser to transmit music playing from my iPod. The laser is hooked up to the iPod through a circuit, and there is a solar cell that the laser is pointed at. There are two wires coming from the solar cell that are connected to a stereo...
  43. R

    Grabbing the ends of a transmission line

    If you have a two-wire transmission line that is open-ended at the load, and connected to an alternating voltage generator at the source, then the voltage between the open ends can be as high as twice the voltage of the generator. However, if the two ends are shorted, then the voltage would be...
  44. timthereaper

    Power Transmission via AC current

    I'm a mechanical engineer and I'm really interested in electrical systems. I understand a fair amount about the basics of E/M and circuits. But no matter how much I read, I can't wrap my head around how AC systems generate power. I do know they work (obviously, right?), but I'm trying to imagine...
  45. P

    Power Loss in transmission lines: Which method is correct?

    Here is the problem: http://postimage.org/image/1jy6nol5w/ Method 1: Steps 1. Calculate V(T1)=12*10=120V, V(T2)=10*10=100V 2. Since V(3)=10V and I(3)=1A, P(T3)=10W 3. Since not otherwise stated, Assume transformers are perfect. 4. So P(T3)= P(T2) = 10W 5. known...
  46. C

    How does a coaxial transmission line work?

    On a coaxial transmission line is there AC current running through the center wire? And this AC current produces EM radiation that bounces down the wave guide. So is the purpose of this transmission line to send the signal via radio waves. And is this how cable tv works, are radio waves being...
  47. F

    Optics - Transmission of plane wave at oblique incidence

    I have 2 questions that need help with, Considering the following plane wave, E= 30 (0.866 i + 0.5k)exp{i(-0.5x + 0.866z)} firstly how can i deduce the direction of the electric field oscillations? And finally, if the wave is incident on a dielectric interface between medium of Er=2...
  48. C

    Health risks with radio transmission?

    Ok I've done my research and so long as the transmitter isn't outputting at a high level of power, you'll be fine. Why I ask is because I'm looking into getting a job with a small company, where they install network elements such as optical and radio transmissoin (and multiplexers). Now I...
  49. C

    Are there any health risks with radio transmission?

    Ok I've done my research and so long as the transmitter isn't outputting at a high level of power, you'll be fine. Why I ask is because I'm looking into getting a job with a small company, where they install network elements such as optical and radio transmissoin (and multiplexers). Now I...
  50. T

    Transmission line charateristics measurement?

    Transmission line charateristics measurement?? Dear all, I want to do cable analysis of a 3800m long twisted pair wire to set up a communication system. It is not usual twisted pair wire (telephone), has different impedance, R=194, L=4mH, C=180uF. The things to be analyzed are...
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