Announcements
Last Updated: 2 April 2007
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Spring 2000 Announcements
The class schedule may be changed as the semester progresses, but the key dates -- quizzes, homework, projects -- will remain the same.
Class notes, copies of lecture slides, lecture quizzes and grade information are all available through the RPI LMS (formerly WebCT). To access any of these materials, you must begin by logging onto the ECSE-2100 Fields and Waves I from the Course List. The format used for the WebCT pages is still used so that accessing some information may be a little inefficient.
During classtime for the last few meetings of the term, there will be extra credit exercises each day. In addition, there is an extra credit project (information on the Project Page) and there will be an extra set of WebCT questions (like the lecture quizzes) available after the third quiz. One difference in these questions is that you will have only one chance to answer each question.
Office hours are posted by the names of each instructor or TA
There will be extra open shop on Sunday, 22 April, from 1-5 pm in JEC 4107. Alfonso's open shop on Tuesday, 24 April, is canceled.
See Handouts page.
HW 1: You are not specifically asked to do the PSpice modeling for HW 1. Rather, doing it will help you to recognize that you have correct results when you make your measurements in JEC 4107. Since this is not a requirement, I have posted sample results with the HW assignment on the Handouts page. You will have some PSpice modeling to do for future homework and project assignments, so you should try to make this work and get help if you have problems. After working with a few students who were unable to get the lumped model I posted work, it appears that this cannot be done. I tested it, even changing the names of the files and I was always successful. However, I could not get the file to load and run properly on other computers.
For the experimental measurements to be done in class, I have a couple of suggestions & comments. First, the lumped circuit does not respond exactly like the real spool of transmission line. The lumped line is, in fact, only a good model for the cable at frequencies well below 1MHz. However, you should still be able to observe the main features of the standing wave on the line. That is, once you adjust the frequency so that the signal is very small for node 17, you should be able to find another node with a reasonably small signal. It may not be as small as the signal at node 17, but it should still be smaller than its neighbors. It should also be about a half wavelength from node 17. You should compare the separation of the minima with a half wavelength.
A hint regarding traveling and standing waves. The general form of traveling waves is found on slide 38 for lecture 2. The general form for a standing wave is found on slides 47 & 48.
HW 2: When using the lossy transmission line model in PSpice for lossless lines, you have to specify the capacitance C, the inductance L, the conductance G and the resistance R per unit length and the total length of the line LEN. Since the line is lossless, both R and G should be zero. The default values for R, L, C, & G are all 1 so they have to be changed to get any reasonable results.
Note also that you need to do the PSpice analysis with a sinusoidal source and a pulsed source for all three loads. You also need to do the experiments for all three loads. To make the experiment quicker, put a Tee at the load end. Then you can connect a 50 Ohm load to it for the matched case, the 93 Ohm load to it for the second case, and both the 50 and 93 Ohm loads to get the 32.5 Ohm case.
HW4: As a hint on how to do a circle with square cells, consider the following picture, which is one of several options for drawing a circle out of squares. Obviously, if you use smaller square and more of them, you will have a better circle. A second option is to use almost the same squares, but choose only the ones where more than half of the square falls either inside or outside the circle.
There is an example of a spreadsheet used to solve an electrostatics problem posted with HW3 from Spring 2006. You will also find a writeup on the technique posted on the Supplementary Materials page.
Problem 2: Remember that the field expression you are given is only valid for r>>a so you should be able to use some approximate techniques in solving the problem. You can set up and do the flux integral exactly or you can find an approximate solution. You will need to convert from spherical to some other coordinate system that makes the integral simpler. In the writeup it says to convert to rectangular coordinates, but it is actually easier to do this in cylindrical coordinates, because the integral is over a circular surface. You can find information on how to convert between coordinate systems in the text book. There is also a new document added to the Supplementary Materials page -- the Appendices from the online Fields book written by Orfanidis. You should look at this new document in any case since it contains a lot of useful info. Table 3-1 from Ulaby is maybe the most convenient source of this information. If you wish to use a frequency in the expression for the current, use 100Hz. You can also choose 1A for the current magnitude. Neither is necessary, but sometimes it is easier to work with numbers than symbols. Be sure that you are careful in taking the cross product of v and B.
Problem 3: Since the figure came from another source, the dimensions do not have ideal notation. To avoid complications, replace the height symbol H with another symbol like h since H is also used for the magnetic field. Remember that the solenoid has N turns in one layer. Also the inner cylinder has only one turn since it is a conducting pipe. Your answer for resistance will depend on the value you choose for the conductivity of aluminum, for which there is no exact number. Make sure you list the source of your value.
The most up-to-date reading list for the class notes.
The MathCAD Explorer and the Visual Electromagnetics Workbook we use in class can be downloaded from the web. Please see the bottom of the main Class Information Page under TEXT .
Almost any Spice based program can be used to model transmission lines, but we use the PSpice program available through Cadence/OrCAD. The most recent version is the version 10.5 OrCAD Demo, but there is an older and smaller version 9.1 PSpice Student that will do everything we need for this course. If you have not used PSpice for transmission line analysis previously, you may want to review the document posted on the Projects page on Designing with PSpice. There is a reasonably reliable work around that permits designs to be shared. First create the design and simulate it to be sure everything is working well. You will notice that this creates several files, one of which ends in the extension DSN. You can send this file to anyone else to share what you have done. To use the file, open it from whatever version of PSpice you are running. Don't try to run it, however. Rather copy the circuit diagram and paste it into a new project. The new project should now work. You will have to set up a simulation, but, otherwise you will have saved a lot of effort by not having to input all of the parts.
There are many links to useful software and other information in the lecture slides and in the Supplementary Materials Page.
Homework assignments are posted on the
Handouts page.
PDF versions of most course handouts will be available on the
Handouts page. (Accessible from
home page ). You can also access many of them from the
course schedule page .
Quiz Grades and Other
Grade Info
Quiz 1 -- approximate grade breakdown. A: 90-100, B: 80-89, C: 70-79, D: 55-69
Quiz 2 -- approximate grade breakdown is similar to Quiz 1. A: A: 90-100, B: 80-89, C: 70-79, D: 50-69
For Quiz 2, you should review Quiz 2 from Spring 2005 and Spring 2005. However, the scope of the quiz this term is not as broad. There will be no questions on current flow. The only topics will be from electrostatics.
For Quizzes 2 and 3 and the Final Exam, you will be given the full set of formula sheets each time. You will not need the full set, but it is easier to use the same set.
For Quiz 3, you should look over the review questions posted in Spring 2006. Note also the corrections to posted solutions. Also, the solution to Quiz 3 from Spring 2006 had a small intermediate step error that has now been fixed.