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Forgetting Everything after finishing exams

  1. Oct 21, 2014 #1
    Okay i had this huge exam in linear circuits and we studies so much for it because they made us and told it's very important for the future.Then comes a long a time where we studied nothing but maths and we got the point of circuits i forgot most things like when KVL and some other things like short circuits and open circuits
    Is it normal to forget so much things ? for a student
  2. jcsd
  3. Oct 21, 2014 #2
    No, if you forget it , you really never learned it. I got out of school back in 1985. I'm still surprised how much I can apply.

    Remembering details of say a hybrid pi model, you might not remember, but once you get a understanding how the BJT works, you will then be able to sketch the model based on your understanding, no need to remember.

    Focus on understand vs memorizing. huge difference.

    KVL, KCL , Ohms Law , Superposition : Got to have these down or the rest will be a blurr. When you get real smart you apply all 4 of these concepts at the same time and you can do problems by inspection in 1 step.

    Interested? Go research "Driving point Impedance Techniques". You can do most basic circuits with basic algebra skills, including feedback circuits. You can apply them all at same time because you understand the concepts.
  4. Oct 21, 2014 #3
    Forgetting everything isn't normal
  5. Oct 22, 2014 #4
    Well not everything but the concepts are never forgotten just some details about a little things and such
  6. Oct 22, 2014 #5


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    Staff: Mentor

    One thing that helped me a lot was to make up "crib sheets" to use for studying for exams. They would be 1-2 pages of the relevant equations and techniques for solving problems that would be on the exam. Making up the sheets helped me to study, plus I had them after the exam to use for reviewing and refreshing on material. I'd use the crib sheets from my midterm exams when studying for my final, for example. And later on if I needed to refresh on some subject (like E&M, or Antennas, or DSP, etc.), I could pull out my old crib sheets. :-)
  7. Oct 22, 2014 #6
    Forgetting details not a problem, just need to remember enough so you know where to look.

    Understanding Concepts is what will pay off in industrial setting.

    At one point in my career, I used to interview engineering prospects for technical merits. You would be surprised how many BSEE 's could not even draw a voltage vs time curve for a circuit with a battery, resistor, switch and capacitor. Open and close switch and I was looking for the charging and discharging curve on the Capacitor.

    These engineers didn't learn concepts. Still don't understand how they got degrees.

    I was always looking for folks that could think, not memorize.
  8. Oct 22, 2014 #7
    Memorizing can help you understand and vice versa, they aren't mutually exclusive.
  9. Oct 22, 2014 #8
    Yes sometimes memorization is necessary, especially with the nomenclature, but that's really the only place it applies, memorizing derivative and integral tables may be useful for the test but know how to derive (by truly understanding the math, knowing the intuition and reasoning why the mathematician or physicist took the steps they did) makes it a lot easier to remember long term than just memorizing the tables.
  10. Oct 22, 2014 #9
    This is such a vague topic, and what each of us perceives as memorizing vs understanding. Most of my Jr and Senior classes were open book. Some classes would give you 4 problems on a test and you just had to do 3. He was known as one of the tougher PhD's in the college. Hard to get an A, but I sure learned a lot from him. He always said you will have your books and motes in real world, so you can use them here. Anytime a problem started out saying "Joe Ham decided to design a ...." I knew to skip that problem.

    To students, do what works for you, you are professional students and should know how to take tests and study.

    One of the best interview answers I've heard. What did you learn in school? I learned how to learn new concepts in rapid time frames.
  11. Oct 23, 2014 #10
    Amen. As you say, though, it is normal to forget the basics--it's just that it shouldn't be normal. It's refreshing to hear someone say that engineering isn't just about memorizing and plugging and chugging and just practical skills alone. That's what I've always believed, although I've never had the chance to work as a practicing engineer, so I can't be too sure.

    On a side note, this kind of proves my point on that other thread about how it would make sense to hire me, the topology PhD with an EE background who excels at understanding concepts over someone with the full BS EE degree. HR will have none of it, though. Or maybe it's just that I suck at getting jobs. But they sure don't make it easy if you don't have the degree.

    I still remember KVL and KCL and all that after like 10 years since I used it in my EE classes. Maybe it gets hammered into you enough with repetition by the time you've taken several circuits classes, but it does help to have a picture in mind my of the electrons flowing like water, such that you have to have the same amount come in as go out for KCL (or to put it another way, if you add up all the current coming into a node, it should be zero, or else there would be charge building up at that node). If you just think of it as dry facts, just the symbols in the equation, it's not going to be memorable. It won't stick, so you're mostly wasting your time learning it because you'll forget it all in 2 seconds, anyway.
  12. Oct 23, 2014 #11
    I think it depends a bit upon the person. Unless I keep actively doing something I tend to forget a lot. Even basic stuff. Although if I go back and glance at it I pick it up again 1000x faster than the first time and sometimes all I need is to glance at the formula and then I remember everything about it again right away. I was also generally better at figuring things out than raw memorization for math and physics. Of course most tests have time limits so there is only so much you can re-derive from very basic points and logically managing to think things through and build them up step by step. I was someone who would tend to do better and better on a really hard test the more and more time given while I noticed that many people seemed to pretty much do what they could after a bit of time and they didn't seem to be able to keep going and if they were given a ton of extra time it didn't seem to make much difference for them.

    I was pretty good at memorizing short lists of vocab words for French class or things in biology so long as it was not biochemical pathways and cycles though. A bit less so at long passages of speech or math and physics formula after formula. I tended to do super well, basically 4.0 or nearly so on every take home test ever, but sometimes a bit worse on in class tests and my relative difference between those two could be noticeable at times and a bit more than it seemed for most. Even those who would easily ace every in class test without a sweat I'd end up virtually always managing to top for take home tests.
    Last edited: Oct 23, 2014
  13. Oct 23, 2014 #12
    Not to take away from all the effort and knowledge gained getting a degree, Think about how many try and don't make it for so many reasons. Not the easiest challenge.

    But looking back, School was just a stepping stone to tweak my brain some to think a little differently. Late nights working on crazy problems and all of that.

    I was lucky enough to get into a engineering job for many years where I was surrounded by PhD physicists , engineers of all types, Material scientist , chemist, talented machinist, E techs, and model makers to name a few.

    We were given tight timelines and plenty of money to design and make our OEM equipment. Some of the challenges we had we stiff, but we always seemed to make the impossible work. After a big project, I would always scratch my head and think WOW it actually works. A solid team of many types of people was key to this, Applied Engineering in the Free Market is where I really got my education. At this point in my career many think I'm actually a Mechanical Engineer, which is a little funny, I sure have had my hand held many years by my network.

    I know I was lucky with the job that I had, kinda thought of it as a large sand box to play in. I'm sure there are many engineering jobs where one doesn't get to work on so many different types projects.

    One of the best EE candidates I interviewed was a Physicist. Boy could he do circuits. The day I interviewed him, I was working on this PCB card that was designed before I worked there. I couldn't figure out why there were 3 different NOT gates on the card. It was just an enable signal to trip a IC relay. I gave this the candidate, he went thru all of the logic and each Gate that was totally different. But anyway he got the question right, no logic at all to have 3 gates, he said "I have no clue." I told him CORRECT. Later I figured out why, 3 different EE's worked on the PCB, and each designed their own NOT gate. Go figure, keeping them all happy all 3 were put on card.

    Guy didn't get hired, even though the whole group wanted him. Boss said he wouldn't stay long in our group before another would steal him from us, and we would be back where we started looking for an EE. We were ticked off, we could have trained him up, and then when he bailed he would come back to us as an internal customer who knew how we worked...

    Anyway, sorry for long story, but just an example that not getting the job, sometimes it is not you.
  14. Oct 23, 2014 #13
    Good point, I still have all of my textbooks, my home office is a huge technical library now. Web is great, but nothing like reading the book you learned out of.
  15. Oct 23, 2014 #14
    It sometimes depend on whether you really want to remember this information or not.
    And it depends on whether it interests you or not.
    Your brain only stores things that excites and interests you.
  16. Oct 23, 2014 #15
    It doesn't prove your point, not really. Engineering can be almost as theoretically rigorous as physics (probably not math though) and in that sense having intuition for the concepts is very useful. Just as an example in my current job, high frequency voltage oscillations came about during product testing of a system we were working with and the main engineer figured out it was increased (di/dt)'s being generated by a current loop due to the configuration our wiring and grounding setup was in, just by looking at a voltmeter. His understanding of the concepts told him what was going on but his practical skills were what lead him to fixing the problem. The 'simple' act of understanding concepts doesn't mean you can build or program electrical systems well, which is what EE is actually about, you need both. If EE experience means classes than I would probably be skeptical about hiring you as well. If EE experience means hands on practical work than I would say someone with a math background would be valuable, depending on the job.

    On the topic of the thread, the people parrotting this intuition only mantra are doing more memorizing than they like to admit; I wouldn't say it's a semantics game, but they're strawmanning and pigeon holling what memorizing is IMO.
  17. Oct 23, 2014 #16
    Okay, then maybe what we should say that the way in which you memorize the material (with the definition of memorizing being : commit to memory; learn by heart.) is much easier by thoroughly learning the concepts, and intuition behind the steps than just repeatedly doing the problems over and over.

    There's a reason I'll never forget what d/dx e^(x) is, its because I know how to derive using the limit definition of a derivative, and I know to apply the a limit to f(x+h)-f(x)/Δh because if you tried to just compute it as is, you obtain an IDF, so you approximate it using a limit(because that's what limits are, approximations), and finally I know to substitute the limit definition of e into the limit definition of the derivative of e because of how Jacob Bernoulli came upon e when tackling a problem regarding compound interest
  18. Oct 23, 2014 #17
    Well yes actually, I think the knee jerk reaction most people have to the word memorize is to picture someone sounding off the same equations over and over until it sticks without understanding what they mean. This isn't the case, being able to derive equations helps the concept stick and helps stick the concept into your memory which in turns helps you learn more concepts which the previous one built the foundation for. Understanding and memorization is not mutually exclusive.
  19. Oct 23, 2014 #18
    Sounds like you were working for a TUV inspection. High frequency noise on ground plane use can be interesting. Been stuck in that situation, my problem wasn't the design but just a miss wire of a neutral hooked the the ground bar. One of my super techs figured it out. I sure thought it was me not thinking my design out properly. Ground, neutrals, and ground loops is still one of the most challenging aspects of a system design, and it's overlooked too often.
  20. Oct 23, 2014 #19
    Yep, and it can happen on almost any system as well. I work as an EE now, but I also did physics as an undergrad and I had the opportunity to perform plasma research at a Tokamak, the first three or so days was cleaning up ground loops between the different DAQ systems so we could get clear signals from our detectors. Interesting how it's brought about and even more interesting the different McGauyver solutions there are for fixing it.
  21. Oct 23, 2014 #20
    Best way to fix ground loops is to have them. I know that sounds easy, but having been under the bus a few times, so I have been focused on it for a long time. Ground Arcs and Plasma , I'm actually used to that stuff. I work in the Vacuum Deposited Thin Film Market when I'm not making speargun tips.

    I think we took a left turn on intial topic of thread.
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