PHYS345 Electricity and Electronics

Student Suggestions and My Responses

(Also, see Student Requests for Clarification.)

My responses are italicized. I sometimes edit slightly, truncate, or abridge the submissions. Listed in reverse chronological order. Make a suggestion!

  1. What is that embedded code on the left hand side of the web page anyway?? [12/12 12:25am]

    I forget... ;-) [12/12]

  2. When will our final grades be calculated? [12/11 2:10am]

    Final grades should be available by Tuesday morning 12/14. [12/11]

  3. Is this exam on all of the information of this semester? Or does it just deal with the stuff from digital logic to op amps? Thanks for responding quickly. [12/1 2:54pm]

    The emphasis of the second exam will be from digital logic through op amps. This includes Chapters 12, 13, and 14 and the classes from Oct. 12 through Nov. 16.

    However, as with most science and engineering courses, you should be ready to use the concepts introduced earlier in the semester as needed. [12/1]

  4. We all have a math exam on wednesday. It is a very comprehensive test and will be very difficult [take many days to study for]. I was wondering if there were any way we might be able to postpone our physics exam until the following Tuesday. This would be a great help to us all. ... It will be very impossible for us to concentrate on studying for the physics exam, which will need many days to study for, when we also need to spend several whole days studying for the math exam. [11/28 12:15am]

    Sorry, I cannot move the exam later. It is scheduled for the next to last meeting of our class. Since the MATH course actually has three class meetings remaining after its exam, perhaps its exam can be moved. [11/28]

  5. Is there anyway to extend this homework. With all of our tests and problems sets we have barely had time to try it. On top of that I can not get anywhere and no one I have talked to has either. With Thanksgiving it will be difficult to finish for Wed. many of us are leaving. [10/22 9:26pm]

    I was wondering if there is anyway to post more hints or discuss or even extend the due date of this homework assignment past Wednesday. I know of several students including myself who have been having difficulty completeing this. Many of us have gotten nothing. It has been especially difficult since this week is crunch time--we all have an exam tomorrow as well as other homework assignments. Thank you for your time and consideration. [10/22 1:20pm]

    I understand the time crunch you are facing; however, I am reluctant to extend the due date further. When you return from Thanksgiving break, I would prefer that you be spending time reviewing and preparing for the upcoming midterm exam rather than catching up on the homework. Turn in the homework by Wednesday before you leave and enjoy the holiday, rather than worrying about your pending homework assignments. Also, it is likely that I will be doing at least one (or maybe even two) of the homework problems in class on Tuesday before break, so make sure you attend class! [10/23]

  6. Is it possible to have our second exam on Thursday the fourth instead of the second, because a good amount of us have a Math 351 Exam on the first? [11/16 2:52pm]

    The midterm exam is scheduled for Thursday, December 2. There is no other time to schedule it; I would not like to offer the exam on Tuesday, Nov. 30 since it is immediately after the Thanksgiving break. Nor would I like to offer it the last day of class on Tuesday, Dec. 7. [I am required to hold exams during normal scheduled class offerings.] Also, remember that our final exam is Friday 12/10 at 10:30am. [10/23]

  7. This seems a little strange, but for the past couple of classes the class room has been extremely cold, colder than it is even outside. Just thought I would let you know. [11/10 3:50pm]

  8. Could you give us an activation code for ewb that comes with the book? I only ask so we can use it to the fullest without paying another 70 bucks, the book cost more than enough by itself. [10/8 12:15am]

    No, I am not able to provide you with an activation code. Sorry. [10/8]

  9. I would like to suggest a few words about persistence to aid our class through these troubling times:

    • Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genuis will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. -Calvin Coolidge-
    • The harder you work the harder it is to surrender. -Vincent Lombardi-
    • I start where the last man left off. -Thomas Edison-
    • I think and think for months and years. Ninety-nine times the conclusion is false. The hunderdth time I am right. -Albert Einstein-
    • Your persistence is you belief in yourself. -Brian Tracy-
    • Failure is only the opportunity to begin again more intelligently. -Henry Ford-
    • Do not despise the bottom rungs in the ascent to greatness. -Publilius Syrus-
    • *The only time you can't afford to fail is the last time you try. -Charless Kettering-
    [10/25 9:24pm]

  10. I would like to suggest, on behalf of our class, that you allow us to use a one page formula sheet during the midterm exam. I am sure that you probably have doubts as to the merit for such an allowance; however, I assure you that this practice will not impede our efforts. Instead, it shall facilitate a deeper appreciation for the material by freeing our minds from time consuming and mundane memorization. The material, itself, is complicated enough as to require a deep understaning to apply in practice. This understanding can not be achieved simply by having the equation in front of us. In addition, I do not believe that it is fair to punish those of us who understand the material and would falter on the exam from poor memory, while at the same time rewarding those who do not understand the material but would score higher because they were able to jot done enough equation to earn partial credit. Therefore, I would like to ask you to please accept this contemplated suggestion with an open mind. [10/25 9:18pm]

    Traditionally I have compromised on this issue. For PHYS345, I permit a 3"x5" notecard for the final exam. In PHYS208, I provide a simple formula sheet since that course is more heavily invested in a myriad of formulas. However I truly believe, although you may respectfully disagree, that this course is not driven by many formulas. I have structured your exercises in the laboratory, in homework, and in the quizzes so that you have experienced enough work with the course material so that the few equations that you need should be fairly well ingrained at this point. Often a false security comes when the availability of a notecard is announced in a course, subverting active engagement with the material in a steady and deliberate pace. [10/27 5:20pm PST]

  11. Instead of transmission lines, a filter lab would be better in the future. [10/22 9:46pm]

    Yes, I was thinking in that direction too. I will probably try to develop a lab exercise using circuit simulation using Electronics Workbench combined with construction and testing of a real filter. [10/22]

  12. Can you post a sample quiz or problem about what is going to be on the quiz tomorrow? [10/20 9:08pm]

    OK, how about something like this: [10/20]

    Design a high-pass LR circuit with a cut-off frequency of 10 kHz. What is the gain in dB at 5, 10, and 20 kHz?

  13. Did you say that you will spend some time in class tomorrow to review for the quiz??? [10/20 9:09pm]

    Sure, if I forget, just remind me! [10/20]

  14. Please, Please, Please, spend 10 minutes today reviewing transient circuits. I attempted to study Ch. 5 last night, but had a difficult time understanding. Specifically, with respect to your quiz on this topic: How can I determine how the circuit will behave at t=0. In that quiz, you stated that the 6 ohm resistor would have no effect on the charging of the inductor----please review these concepts again. Thank you very much! [10/14 8:49am]

    OK, I plan to do so. [10/14]

  15. Abridged: ...We have been struggling in this course for quite some time now, with little hope in sight.  We got lost early, and with a full semester of classes, it is hard to catch up.  Complex circuitry and some other subjects have been giving us a lot of trouble.  We feel very insecure, and are worried that we are almost dangerously behind.  We are sending you this email as a call for help.   While we have handed in the majority of the homework, there were several assignments that we did not hand in, or handed in having no clue what we had done. ...  My main point is that the test date is fast approaching and time is running out to get our feet firmly on the ground.  We are asking you what we should do. ... We are going to try and cram our schedules so that we can make your office hours, if we can't make them (primarily due to class) then we will try and set up appointments with you.  If there is anything else you have to offer, i.e. a tutor, please let us know. We are in need of help. [10/12 8:21 pm]

    As you know, we have two weeks before the exam, which will cover the material prior to the class of 10/12. I think that should allow adequate time to "catch up." One way to fix the gaps in understanding is to figure out what you do know and what you do not yet know. As you have mentioned, this is probably best done during an office hour. If the office hours are not convenient (and can sometimes be full of interuptions anyways) suggest a time or two that would be convenient and I will see if my schedule is free then.

    I contacted some of the best students from PHYS345 last year to see if they were interested, but it seems that they are busy with their own studies and other activities. Finding a capable EE major for a tutor would also be a possibility, but I am concerned that they would not be familiar with the scope of our survey course, and could make matters worse. Similary, our physics students typically do not have a circuits course like PHYS345 and will not know many of the analysis tools that we use. In short, I am not able to recommend a tutor for the course...

  16. I do not think that three days is enough time to write up the labs, considering homework is due the next day. [10/ 10:29am]

  17. I have been having a really hard time doing the homework. I have spent alot of time on it. The problem is that most of us have a very big test on Tuesday. I have been trying the homework al weekend but to haven't been getting anywhere. I know this is a lot to ask, but could we move the Homework due date until Thursday so we can get another day of lecture and and extra day to work on it? [10/10 11:35pm]

    The beginning of this week is very busy for us. Do you think it would be possible to push back the due of the homework until thursday so that I would have time to actually do a good job on it. I am afraid that if it is due tuesday I will get tied up with studying for my mechanics of solids test that I will not be able to allow ample time to complete the homework. Thank you for your consideration. [10/10 11:40pm]

    Can we possibly move the due date for this homework to Thursday of this week. I have worked on it and havent gotten a single one. I want to spend more time, but i have a solids test and a statistics test too!! Thanks so much for considering!!! [10/10 11:42pm]

    I'm having a really tough time attempting to do the homework. I'm also struggling to try to study for my mechanics of solids exam on tuesday. If there is any chance you could push the homework due date back, I'd greatly appreciate it. [10/10 11:48pm]

    I have been having a lot of trouble with the latest homework assignment. I have talked with several other members of the class and they have not gotten anywhere on the homework either. I have worked in excess of two hours on only the three problems from chapter 6 and have not gotten answers to either three. Neither have the other members of the class. We also have a rather large exam in a class on Tuesday. I personally was wondering if there was any way to delay the due date of this assignment. Thank you for your consideration. [10/11 7:13am]

    When is the latest that the homework may be turned in for full credit? [10/11 1:55pm]

    A number of us have worked on the problems, but haven't gotten anywhere. We've skimmed through the chapter, used our notes, and the hints that you provided, but we still can't work the problems. In addition, we have a Mechanics of Solids test tomorrow, Tuesday Oct. 12. We were hoping that you could give us an extension on the due date of the homework; preferably on thursday which allows another class and a review session. We'll appreciate any leniancy you can provide. [10/11 1:29 pm]

    Delay homework due tomorrow. Most of us have two exams, two labs and three homeworks happening in the beginning half of the week. An extra day, possibly allowing the homework to be due at the discussion session would be greatly apprecitated. Also the extra day would clear up a lot of questions some of us are having with the homework. Thank you. [10/11 1:56pm]

    I have no problem extending the deadline for homework until Wed. evening. But I would like to have a quiz on Transients in RC and LR Circuits on Thursday. That means that I would like to discuss that material at the review session on Wednesday evening. So I cannot extend the homework submission until Thursday.

    I don't want to generate a backlog of work and topics by delaying your mastery of these recent subjects. We are rapidly approaching the study of digital systems, so there may soon be a brief respite for you. Sounds like Friday's Fall Break was not long enough... [10/11]

  18. It would bring me satisfaction if the errata page was informatively sent to the publisher of our text book. They charge so much for it that it could at least be a reliable resource for its students. [10/99:28pm]

  19. Cool lab this week, can we use that program on the exam? [10/6 9:00]

    I agree that Electronics Workbench is an effective and easy-to-use tool for circuit simulation. You can probably understand why I held back its introduction until you were firmly grounded with circuit analysis techniques. It would be interesting to consider using it in an exam situation, but it won't be possible this year unless everyone brings a laptop to Gore Hall (a distinct possibility in future years!). I am considering the possibility of a lab practical exam at the end of the year; it could include a circuit or two for EWB... [10/7]

  20. It would be better for several of us if the review session for exam one was on monday! ... Thanks for considering!!! [10/6 12:40am]

    I was wondering if there was any possible way to move the review session from the sunday before the test. Thank you. [10/6 12:44am]

    Unfortunately the only evening that I am available the week of the exam is Sunday. Sorry, but it must be Sunday evening... [10/6]

  21. ... I appreciated your summary in today's lecture. However, your lectures still miss the mark. The mathematical explanations are fine, but without the BACKGROUND explanation it is very hard to piece the two together. For example, today we talked about AC filters, but you never explained what an AC filter is, what it does, or why one would use it. I truly believe that your class could be so much more if you would just provide perspective. Thanks. [10/5 6:48pm]

    OK, I'll see what I can do. [10/6]

  22. And just exactly where do we start problem 7.16? [10/4 9:19pm]

    Thanks for the inquiry. I hope my discussion of the circuit during class today was helpful. [10/5]

  23. You have been so focused on the misunderstanding that we do not understand how to work with complex numbers. This is a misconception, our calculators do most of the work. Complex numbers really are not that difficult to work with. I believe the real problem in our class is the lack of continuity between lectures ever since the missed class day. I wish you would step back for a few moments and put things into perspective--forget about the numbers for a few minutes and just explain what is happening. What are we doing and why are we doing it? Also, I would appreciate it if you highlight or indicate the material from each chapter that we need to know for the exam. For example, from chapter 4 you should be able to....., etc. Thank you. [10/3 11:28]

    Glad to hear that you are comfortable with the complex algebra. As you say, I was beginning to worry. I will spend some time in class on Tuesday giving the overview of where we have been, where we are going, and why, as well as tying up some loose ends. [10/3]

  24. Is there any way that you can change the date of the first midterm exam? A lot of us are currently taking Engineering Statistics and Probabilities [STAT250] and have a major exam on that same day. If so, it would be much appreciated. [9/30]

    You have a choice between Tuesday 10/26 and Thursday 10/28 for reasons that I will explain in class. If your classmates are in agreement, I can reschedule the exam for Tuesday. We will discuss further in class... [9/30]

    Update: As discussed in class on 10/5, there does not seem to be a conflict. We will keep the exam as originally scheduled for 10/28. [10/5]

  25. Argh! Why are lab reports due in just two days? [10/29]

    After discussion with Mr. Xiang, following suggestions from several students, we have decided to make labs due in the drop box by Monday at noon. This should give you as much time as needed to work on the lab exercise and write your report and still give enough time for the reports to be graded and returned at the following week's session. [9/29]

  26. I'll be honest, this week's homework on phasor analysis has murdered me. I don't think I've ever spent so much time with such a frivilous gain in overall understanding. I was hoping you could give us some weapon to use when attacking the homework and exam problems on phasor analysis. [9/28 8:37am]

    I prefer to think of knowledge as a tool rather than a weapon. ;-) However I hear what you are suggesting and I plan on working through one or two detailed examples in class on Sept. 30. [9/29]

  27. As much as the example helps for the first set of problems, I'm still banging my head on the wall about the second set....HELP!!! [10/27 11:40pm]

    Try moving further from the wall... Seriously, remember that for the current through a section of a circuit to be in phase with the voltage across that section of the circuit, the net reactance in that part of the circuit must be zero. [9/27]

  28. We are having difficulty solving the problems due tomorrow. Specifically the problems dealing with impedence in parallel, there really are no examples in the book and we are just not sure how to go about solving them. We can get to your hint in most cases. Can you put an example on the web, or explain how to do this briefly? Thank you for your time and we apologize for any inconvenience. [9/27 4:27pm]

    I have been working on the Physics homework for quite a while now and I am having difficulty understanding how to work out problems which have impedance in parallel. If you could give me direction as to how I should do this by pointing out where in your notes or in the book that I could find this, or just briefly explain, I would highly appreciate it. Thank you for your time. [9/27]

    I have added a detailed numerical example of two reactive branches in parallel to Class 7. I hope you find this to be of help. [9/27]

  29. I have been doing very poorly on the quizzes, and I am not sure what to do. ... I know we are to move on and I want to make sure I understand the concepts we've already covered. ... [9/24 3:54pm]

    One thing is that the ac circuit analysis homework, etc. will give you a chance to review the dc circuit concepts.

    For the quizzes, I would recommend taking last year's quiz as a diagnostic the evening before this semester's quiz. Don't look at the posted solution until after you do as best as you can on your own.

    Finally, during office hours, I can observe a student's circuit analysis process while working on a new circuit. Sometimes I notice a misconception or something that can be modified. [9/25]

  30. ... I was wondering, since we did not have class on Thursday, 9/16/99,  will the quiz be moved to this Tuesday, 9/21/99 or will it be held off till this Thursday 9/23/99? ... [9/19 6:08am]

    Yes, there will be a quiz on nodal/mesh analysis on Tuesday 9/21 and one on Thevenin generators on Thursday 9/23. [9/19]

  31. I like the excerpt about quality from "Zen and the Art of Motorcycle Maintenance" it gave me a litte chuckle. Thanks! [9/14 2:40pm]

  32. Are we allowed to cut and paste from the lab diagrams and use them in our lab reports? For example, using the picture of the setup. [9/14 2:35pm]

    Yes, most definitely! That's the nice thing about web-based documents -- it is so easy to copy-and-paste. It would be a good idea to give attribution to the source -- you may also edit my drawings as you see fit for use in your lab reports. [9/14]

  33. Just wanted to say that I think the design of your class provides a real opportunity for students to learn and grasps the concepts presented. Thanks for putting so much effort into the web pages. [9/10 2:18pm]

  34. Do you have office hours. If so could you let us know when they are? [9/9 11:09pm]
    Nevermind I found them. [9/9 11:12pm]

    Let me remark on office hours anyways. My regularly scheduled hours are Monday and Tuesday 1:30-2:30pm and Wednesday evening 7:00-8:00pm. However if you find that your schedule prohibits you from meeting me during the regular hours, you may e-mail me for an appointment at a mutually convenient time. [9/10]

Fall'98 Suggestions and Responses

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Last updated Dec. 12, 1999.
Copyright George Watson, Univ. of Delaware, 1999.