Transmission Definition and 753 Threads

Homework Statement You have been asked to develop a cross-country DC electrical transmission line to deliver 300MW of power to a town 200km away. This design is to only have a 2% loss (98% efficiency). If the line voltage is 600kV, what is the minimum diameter that the aluminum wire can be...

Does a DC transmission line for a given amount of power, do better at higher voltage? I know power is the product of the Voltage and current. The logic given to me by one of my peers was that I2R losses are less if the current is low. And so for a given power, it would imply V to be higher...

Hi when using the WKB approx, is there a general method to find these Refelction and Transmission coefficients, I have tried looking in books and on the net and I can't find a 'general' formula, they tend tjust to be quoted. I know that |T|^{2}+|R|^{2}=1 . And generally that T=...

So couple questions. My assumption is that a radio antenna gets bombarded with all frequencies at the same time. So there has to be a discriminating circuit with a radio to act as a frequency filter. Well could I do this naively with a low pass filter and a high pass filter together? In...

I use transfer matrix method. I try to plot the phase Φ(ω) versus frequency ω graph in the vicinity of a band gap. The transmission coefficient t(ω) is t(ω) = |t(ω)|*exp(i*Φ(ω)) from which I get the transmission phase Φ(ω) = atan(t_imaginary(ω)/t_real(ω)). Since I assume that -pi/2 ≦ Φ ≦...

Homework Statement A pulley 150 mm diameter is driven directly by an electric motor at 250 revs min-1. A V-belt is used to transmit power from this pulley to a second pulley 400 mm diameter against a load of 200 Nm. The distance between the centre of the pulleys is 600 mm, the included...

In transmission lines the the voltage is stepped up to a specified level thereby reducing current to ensure its transmission with minimal power loss. But we know that P=V*I so by increasing the voltage won't Powerloss gets increased?

Transmission line equation is of the form- Φ(x, t) = F(x − ct) + G(x + ct) where F(x-ct) is the forward traveling wave and G(x+ct) is the reverse traveling wave 'x' is the distance from the origin. Now my question is where does the origin lie? Usually in Transmission lines we assume...

Hi there; I am trying to make a MATLAB program to do an amplitude modulation on a biphasic pulse. The equation I am using is the following: Vout2(i)= (Vc/1000)*(1+(depth.*cos(2*pi*Fm*(i/carrier_freq)))). Where Fm is the modulating frequency, carrier_freq is the frequency of...

I would like to know about radio waves used for FM or AM radio. I have read many articles that say, "The sound is encoded and rides on a carrier radio wave". How is that encoded? I am under the assumption that waves just have a frequency and wavelength and that is all. If a wave is transmitted...

A string with a density/length of rho and tension T has an elastic spring with stiffness k at x=0. There is a step pulse (fi = H(t)) incident on this discontinuity. Determine the reflected and transmitted waves. Im not sure what boundary condition to use at the location of the spring. All...

Hello there! I was brainstorming a lot when I took a walk today. Not that I posses any type of degree in communication, although I find it interesting of IT communication and they techniques we use for cellar communication. NOW to what I thought about. Let's have an example: If I were to...

Take a telegraph line or transmission line which is long. Now slowly the wave propagates through the wire in the forward direction. In the beginning one end of the wire will have a non-zero voltage while the other end will have zero voltage and it takes some more time to get settled after some...

Say you are transmitting AM radio signals. You input an audio signal of 1khz which is used to modulate a signal of 1 mhz. The heterodyning process outputs 4 different frequencies, the audio, carrier, sum, and difference. But where are the sum and difference? If I look at a graph of the...

Recently in the news NASA has transmitted an image of the Mona Lisa via a laser beam and i was wondering about some of the theory behind how they did it and maybe trying to recreate something similar on a (much) smaller scale. I've seen some articles online that show a method for transmitting...

I am new to this forum, and posting in forums in general, so this is a slightly strange experience for me. I would like to kindly and respectfully request everyone's cooperation, and if those posting would be respectful in their answers. I was recently reading through an article on an...

https://www.youtube.com/watch?v=nOzRzmfh884 Unlike other CVTs that use belts or steel balls, this is obviously not friction based therefore it should be more efficient and be able to withstand higher torques without any risk of slippage. The main problem that must be solved is the trepidation...

Hello! I´m trying to read Jacksons 'Classical Electrodynamics' and solving some problems. At the moment I´m stuck at problem 7.3. I started looking at suggested solutions (http://www-personal.umich.edu/~pran/jackson/P505/F07_hw11a.pdf) but I need some help I guess. Looking at how other people...

Why does frequency of a wave stay the same during transmission and reflection?

As part of my school's work experience program I'm going to be spending a week with a HV Electricity design and installation company in their design office. They do pretty much any type of HV installs from renewables like wind turbines to substations and HV transmission lines. I was just...

Homework Statement The Attempt at a Solution I m getting 10V as one side is O.C so the whole voltage come across it...correct me where i m going wrong

Hi I have a question on the transmission coefficient in classical optics. When we say that a medium has a transmittance of e.g. 99%, then 99% of the incident light intensity is transmitted. But will the light also acquire a phase? I tried searching the web, but all I found was this...

I sometimes hear on astronomy documentaries that our earliest radio transmissions could be received by aliens in our galaxy. Assuming the stations power was 1000kw at 1 mile(wild guess on my part) the power of the signal at 1 light year would 1000kw/7 trillion squared. Is this right? If so...

I have to thinking about how the skin effect come into play in transmission lines with two conductors and dielectric in the middle. For normal skin effect, we consider a potential across a conductor as shown: Where the tangential E right above and right below the surface at z=0, are...

Ive never understood why outlets have 3 holes. The two at the top are the voltage in and voltage out, correct? So why is there a ground if the current already has a way to return to the voltage source through the second hole? Also, i am assuming that power lines have two cables coming from a...

I am intending to perform extended absorption fine structure (EXAFS) experiments on a thin film in order to investigate the near order around Europium ions. The thin film is going to be deposited on a silicon substrate, and the question is in reality related to how thick the substrate should be...

Homework Statement What is the input impedance in polar coordinates of 222.85 cm long 50 ohms line with a load of 20-j40 ohms at 300MHz? Homework Equations lambda=v/f Znorm=ZL/ZO The Attempt at a Solution Normalizing the load impedance: ZL/ZO=(20-j40)/50=0.4-j0.8 Plotting that in...

I need to lift 75 pounds when only using 4 pounds of force. Is there a gear set or pulley system that can do that? Thanks

Is long distance "visible light" transmission possible? Hi Lets say i need to transmit a lot of visible light from one place to another. Is this possible to do on long (50~100 miles) distance?

Hi there, I'm stuck with this problem, I've already worked out some algebra but I can't seem to get what I am asked, when trying to solve the equations I simply can't get the answer, so I was hoping you could help me. Here we go Homework Statement Calculate the transmission coefficient T...

Beer´s law does not apply if there is any scattering. In a pure absorber, if 1 layer absorbs 50 % of incident light and scatters 0 % then 2 consecutive layers transmit 25 % of light and absorb 75 %. And so on exponentially. 9 layers of pure absorbers would transmit 0,195% and absorb 99,8 %...

Hello, I need to transmit motion at a 90° angle, I was considering worm gears or bevelled gears, but then I thought about a flexible drive shaft, it would be cheaper and wouldn't have any backslash issues. I need to transmit motion at a 90° angle with a low toque and low RPM, the application...

Hi, I'm kind of struggling on finding information regarding the transfer of 1000MW to a load located 500km away. As far as 400kV transmission line is considered I can't find a design similar to these therefore would anyone be able if the following would be correct: Assumption: (using...

reflection coefficient gamma = ZL-Z0/ZL+Z0. My question is can you calculate the reflection coefficients when ZL has a real and imaginary?Lets say that Z0=50 ohms and ZL = 125 +j40. All my example in books show ZL and Z0 being real only. Well how do you determine reflection coefficients...

Hi, I'm hoping somebody can help me understand something. I'm studying transmission lines and I'm confused about SWR and standing waves on a transmission line. According to my book the voltage on the transmision line is the super position of an incident and reflected voltage wave given by...

Homework Statement A three-phase line delivers 3600 kW at its receiving end at a lagging power factor of 0.85. The line resistance and reactance are 5 Ohms and 8 Ohms per phase respectively. Given that the sending end line voltage is 33kV, you are asked to determine the receiving end line...

Why is an alternating current used for long distance transmission of electrical power ? What about direct current ?

3 masses 120 degrees away from each other each one of 46g is spinning at 600RPM 58mm away from the center and are fixed to a guide pole. The masses are transmitting torque on a surface and the friction between the surfaces is 0.62 The area of contact is 192mm^2. How much torque is transmitted...

I mean even something tiny, like the seat-adjuster...would that electrocute you to death? Is it possible to touch something plastic and still get electrocuted?

Homework Statement If a transmission line operating at 250 MHz has a characteristic impedance Z0 of 50 Ohm and propagation coefficient γ = 0.4 + j7.5 per meter, calculate its primary coefficients R, L, C and G. Hello, I do not know what formula I can use to solve this problem. If anyone...

I've done an experiment for Single Wire Transmission using Steve Jackson's plans. I went through a series of tests to show what works and what doesn't work. I have demonstrated that the technology does in fact work but some claims towards how it works may be false so I have left it up to you...

I have been trying to calculate the transmission coefficient for a quantum tunelling case, but I seem to get the coefficient value more than 1. How is that possible? The equation i used is based on the wikipedia page (I am unable to link because I am underpost). Also typically what are...

Homework Statement The problem that I was working on and was not able to resolve. This is the problem straight from the book: 12.13) The sprocket wheel on the rear axle of a certain bicycle is 10 cm diameter, and the sprocket wheel to which the pedals are attached is 20 cm in diameter...

I know I can make a VLF transmitter by running a software signal generator through a soundcard and into an antenna. What happens if I play two signals at once, do I get two carrier waves? If I use a WAV file (LPCM) and merge two sine waves, will this also create two carrier waves?

Homework Statement I have source with some impedance (say 10 ohms-not shown in fig). since the tx line is 50 ohms, I added a series termination resistor of 40 ohms to match it with the tx line. After the series resistor there is a parallel termination of 50 ohms, which is followed by a tx...

Hi, i just need some help with something, I have been given a question to solve. I need to find a) sending end current, b) sending end power factor c) full load active power losses of a three phase "double Circuit" transmission line...I know how to calculate all of those for a three phase...

Hey! Below you will find a piece of text I found on a paper. There are some things I don't get, perhaps you could help me. What it means for the network to be lossless? Also, why is the power flow equal to Re[Vi(t) Ii,k(t)*] and not outright Vi(t)*Ii,k(t) ? Why the complex conjugate? I...

Homework Statement A randomly polarized beam of light hits a water surface at Brewster angle. What is the intensity of the transmitted and reflected beams? The refractive index of water is n = 1.33 Homework Equations The Attempt at a Solution Since the light is randomly polarised...

I would like to know if the transmission delay of pressure give a differential force on an object ? Example: an object in water, we put pressure with mass over water at right at t=0s. The pressure at right is faster on the right side than the left side (d1<d2). The object seems to move with a...

I understand that pressure is F/A. But whenever they ask me to find the pressure of a book acting on the table, since the object in question is actually the table so is the force the reaction force on the table by the book and not actually weight since weight is an internal force? Again...