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Rate this quantum test

  1. Hard

    1 vote(s)
  2. Average

    17 vote(s)
  3. Easy

    13 vote(s)
  4. Can't say...

    6 vote(s)
  1. Mar 17, 2008 #1
    For those of you who may remember me, I had a terrible term test result for my quantum mechanics test due to a lack of study. Well, my second term was today and I feel it farred even worse, despite actually studying properly. I'm talking in the range of 30%... I have come to a realization I may not be physics material, because quantum physics is my an integral part of my field. If I can't get around a second year course, I have to face facts and choose not to pursue physical chemistry.

    The alternative, which I think unlikely, is that the test was too difficult. This opinion was shared by some of my friends. I have uploaded the test for you to view and decide. I sincerely ask that you be brutally honest when rating the difficulty. I don't want "feel-good" or uplifting messages, just think back to your introductory quantum/modern physics course and measure it relative to that. The test was one hour.

    About the course? Its a second year physical chemistry course at University of Toronto with two terms, the first being thermal and now being the quantum. Its equivalent to a modern physics (aka introductory course in quantum physics). The link to the test is found below. Please tell me what you think, as well as what school you go to and how it compares to what you did in second year quantum. Thank you in advance.

    TEST: http://i29.tinypic.com/2il1z45.jpg
    Last edited: Mar 17, 2008
  2. jcsd
  3. Mar 17, 2008 #2
    The thing about QM is that there's a lot of tedious math, so a lot of people get put off by the up front difficulty. Just by eyeballing it, I saw 45 points that were purely algebra in that all of the relevant information for a simple substitution was given already. That's a fairly short test too. When I took intro QM, the test was several pages with 5-10 parts each.

    Final verdict: On the easy side of average but for a second year class the test could be considered hard.
  4. Mar 17, 2008 #3


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    Now, I am a physics major and don't know what is usually covered in a chemistry-based quantum mechanics course. Going off of my experience in a physics Quantum Mechanics course, these problems seem above-average for a second year (200 Level) course. They are probably average for an upper level undergraduate Quantum Mechanics course They do not seem impossible, but then again I do not know what your time-constraints were. They're not necessarily easy either though.
  5. Mar 17, 2008 #4
    Its an hour long test. Keep in mind we don't know differential equations yet. I didn't find any simple substitutions.

    Not sure what your saying... that they are more suitable for 3rd year or advanced 2nd year?
    Last edited: Mar 17, 2008
  6. Mar 17, 2008 #5
    Honestly, these are the some of the easiest problems in quantum chemistry. I know because I'm a physical chemistry major graduate student.
  7. Mar 17, 2008 #6
    Alright, just don't say it in retrospect. I could easily laugh at people doing mechanics in first year, but I remember it was a pain when first exposed to it especially w/o any calculus. This is a first exposure to quantum done in second year, unlike a lot of other chemists who take their first course in 3rd year. If you found this easy in second year, I appretiate your input.
  8. Mar 17, 2008 #7


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    Well, again, I am also looking in retrospect somewhat from the point of view of a physics major. The problems are harder than what I had in my sophomore Modern Physics course, but like I said, I do not know what is expected in a sophomore Physical Chemistry course. (Also my professor for modern was not the most difficult professor at my university.)

    I can do the problems now, since I am in a 300 level Quantum Mechanics course, but I don't think I could have done them while I was a sophomore in Modern. That's about all I can say, since I have not taken any P Chem courses, and do not know what is required.
    Last edited: Mar 17, 2008
  9. Mar 17, 2008 #8
    i did that.
  10. Mar 17, 2008 #9


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    This is about what I thought, too. These questions are close to representative of first quarter, first test upper-division quantum. I took P-Chem and the questions were about this hard, but that's an upper level course.

    Seems it would be a bit tough if you haven't had differential equations yet :cry: !

    I cringed when I read, "From the lecture..." Arg! I hated test questions from the lectures!
  11. Mar 17, 2008 #10
    well I said average, however after reading your description of the course I'd say above average, the questions are pretty simple in the end, but I'd say the time constraint is a bit hefty.

    if you note they gave you the solutions to all of the problems in the test, the only thing they didn't mention was the ground state of the harmonic oscillator, which I imagine you could have written down, or memorized relatively quickly
  12. Mar 17, 2008 #11
    I did this stuff last quarter. It's not too bad. Most of it was just plug and chug.

    Not once you learn Dirac notation.
  13. Mar 17, 2008 #12
    Its supposed to be virtually the same as modern physics, altho "less rigorous".

    Thank you, that is what I requested. Its just you said you were a grad p-chem student... and I imagine by then this stuff will seem second nature. But if you found this kind of stuff easy in second year undergrad, I guess this reflects my poorer ability.

    I didn't find anything on that test relatively simple... aside from 3b. The prof said don't memorize anything... so we didn't.

    I thank all the posters for the input. I'm afraid its just reflecting my ability. Its better to know sooner than later. I'll definately discuss changing majors with my profs when I get my results. Its clear if I'm weak in quantum I shouldn't be doing p-chem. I could always do this stuff on my own.
    Last edited: Mar 17, 2008
  14. Mar 17, 2008 #13

    Vanadium 50

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    I have a PhD in physics, but haven't done an NRQM problem since I took the class, 20 years ago. Wait...not quite true - I did one for a lecture 5 or 6 years back. It took me about 10 minutes to do the test; 3 minutes for 1 and 2, and the remainder for 3, with 3a taking longer than 3b.

    I think all the problems were quite straightforward - "show me how to get from A to B". This doesn't require you to figure out B from A on your own. I would expect that a student who had a strong understanding of the material covered in the exam (and of course, I can't say how this related to material covered in class) would do well, even if that student was not adept at tedious computations.

    I don't see that this test requires differential equations. It does require one to know how to take the derivative of a product.

    I think it does require the student to really understand similar derivations. Nodding "uh huh" and "that makes sense" to oneself as the professor does the derivation will not be enough to get a high score on this test. One needs to be able to do the in-class derivations on ones own to score well here. Then the student has a real shot of knowing how to best set things up. For example, in problem 1, the first step is to reorder the Hamiltonian into {[things involving x] + [things involving y]}. Then the problem falls right apart.
  15. Mar 17, 2008 #14
    Well, ****. This isn't exactly relevant, but this proves to me that the physics program at my school isn't going to do me any good, and that I'm definitely going to have to continue my undergraduate education at another school after I finish my math degree if I am to have any hope of going to grad school for physics.

    I'm literally at the top of my quantum class (a first year higher level quantum course, which seems to cover similar material; we're using the Griffiths book, and we just finished chapter 2) with a total score of over 100%, and I only have some vague ideas as to how to approach these problems. All we ever do is normalize wave functions and find expectation values. Maybe play with Ehrenfest's theorem or transmission/reflection coefficients.

    Well, I voted "Can't Say."
  16. Mar 18, 2008 #15
    Mathmaniac, Do you mean first year higher level QM course as in First year of undergrad course? If so ... what sort of physics program covers QM in a first year course?

    Bu you say first year higher level QM class, so are you just advanced an are enrolled in a harder class as a first year?

    To the OP,
    Take heed to Vanadium's post as far as what skills were needed on the questions. You are not solving the DE's as the solution is given to you. The prof. is saying here is a solution to this EQ, show me that it is indeed a solution? If that isn't making sense then I would question what the pre-reqs are in math for the class you are in.
  17. Mar 18, 2008 #16
    The last thing I will do is listen to a PhD student who has seen this stuff over and over for 8+ consecutive years, in addition to working with it on a daily basis. Such people have their minds warped when it comes to difficulty of subjects, because they can't revert back to a time when they never had all their intutions. I know this because of the many TAs I've talked with... one was shocked I didn't know what a line integral was when asking him about dot products back in first year...
  18. Mar 18, 2008 #17
    If you are referring to me, I am no PHD student, just a lowly second year undergrad.
    My experience in QM comes fro a Modern Physics class where we did simple solutions to the SE and anything else just from side readings and this forum. However I will say that I have an above average knowledge of maths for someone in my year ( at least at my school ) because I started out head in math.

    I'm sorry if my post sounded condescending. I guess I really didn't mean to question your mathematical ability though that is what I did essentially.
    Could you post a bit more about what you are not understanding on the test? One thin I can do is explain the simpler parts that are just asking to show that the given solution really is a solution. For the rest I'd have to brush up a bit because I haven't seen/ used any QM this semester at all and will not take a formal class in it until Senior year due to study abroad conflicts.
  19. Mar 19, 2008 #18


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    You really shouldn't be asking people here if they think the test was hard. Short of everyone going Daaaaamn, that's a brutal test. I couldn't even do it now, let alone in second year., you're not going to get a consensus on it. I could tell you that it looks fairly fair to me, as I think at that point in second year I was pretty much fully comfortable with derivatives and partial derivatives, but maybe swapping out momentum operators with their respective derivatives would still have been on shaky ground; I don't know.

    The people who you ought to ask are your classmates. What was the average on the test? The standard deviation? If everyone you know who took the test thought it was hard, then it was probably a hard test for you guys, or none of you were prepared for a test like that. The midterm in my advanced quantum class this semester was fairly easy but I think most of us botched it because it was not the abstract formalism we had been expecting but an actual applied problem that we hadn't refamiliarized ourselves with the notation, etc, enough to not suck on the test.

    In any event, there's no reason to give up yet. Unless everyone in the class is doing remarkably better than you you'll probably pull through just fine (perhaps not with as high a grade as you had hoped for, depending on how the prof assigns grades at the end). Plus, things that seem to bowl you over now will likely become quite familiar later, and one day if someone asks you if you think their quantum test was fair you'll probably look at it and think "That doesn't look too bad...".
  20. Mar 19, 2008 #19
    Nah, I mean like, a first semester of QM. Like QM I, only it's just called QM here because there's only one semester of QM offered here.

    I think though, on further inspection, I'd have a good shot at answering some of those. I'm was a bit confused by the wording of the questions.
    Last edited: Mar 19, 2008
  21. Mar 21, 2008 #20
    This is comparable (although a little bit harder) to the material that I had covered in my intro to Modern Physics course (which I took as a Freshman, but most others at my school take as a sophomore). Now that I've taken two more full courses in QM (covering everything at the Griffith's level), these questions are easy peasy. As stated earlier, these problems do not require any knowledge of differential equations, although a knowledge up to an equivalent of calc 3 would be useful.
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