"Experimental" questions on the GRE?

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tiyusufaly
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Joined: Thu Mar 20, 2008 4:49 pm

"Experimental" questions on the GRE?

Post by tiyusufaly » Sat Aug 16, 2008 9:24 pm

Howdy,

My quick question regards just how much in depth the experimental physics questions of the GRE are? I expect that there are the standard statistics, error analyses, etc.. level questions (fairly straightforward). But in how much detail do they ask about specific equipment or experiments? And especially, with regards to equipment, do they ask about relatively higher level electronics (transistors, diodes, applications to filters, A/D converters, etc...) and optical components? Essentially I am asking, are the specific instrumentation types beyond the level of those in a standard general physics laboratory (which has RC, LC, RL, RLC circuits, basic filters, some basic thin lenses, concave/convex mirrors, etc... -> nothing that's not covered in a general physics course)? I expect they ask generally about more advanced modern physics experiments (like the Photoelectric effect, Compton effect, Rutherford scattering, etc...), but are the details of the equipment and instrumentation at a higher level?

a bucket
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Joined: Fri Aug 08, 2008 9:02 am

Re: "Experimental" questions on the GRE?

Post by a bucket » Sun Aug 17, 2008 3:44 pm

tiyusufaly wrote:But in how much detail do they ask about specific equipment or experiments?
I'm no expert on the physics GRE (I haven't even taken it yet) but what I've noticed on the practice questions is that ETS loves oscilloscopes (and on a more unrelated note... positronium). I would suggest doing one of the practice exams to look for problems related to experimental methods.
tiyusufaly wrote:Essentially I am asking, are the specific instrumentation types beyond the level of those in a standard general physics laboratory
Questions related to RC, LC etc. have popped up in both the practice exams I've gone through. I've only seen one question about filters and it was a really simple one (the most basic R-C low/high - pass filters).
tiyusufaly wrote:I expect they ask generally about more advanced modern physics experiments (like the Photoelectric effect, Compton effect, Rutherford scattering, etc...), but are the details of the equipment and instrumentation at a higher level?
These questions are more like:
- Find the cross-section of scattering of the blahblahblah atom given thisandthat empirical data.
Or
- Invisible colored light of wavelength ??? nm is incident on a spoonful full of kryptonite and the energy of ejected electrons is omgwtfpwnbbqsauce eV. Find the work function of kryptonite.

you get the idea....

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Unnatural Log
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Re: "Experimental" questions on the GRE?

Post by Unnatural Log » Mon Aug 18, 2008 11:21 am

You should definitely know the formulas that apply to the photoelectric effect, compton scattering, etc, like hf = W - Emax. Of course, you also need an intuitive feel for these phenomena. I think there are consistently multiple questions on these topics.

As far as advanced circuit stuff, I won't make any promises, but realistically, you probably only need to know what the basic filters and basic logic gates look like. I think you're better served spending your time studying RLC circuits.

For optics, in addition to what you listed, learn the basic properties of a telescope. You know, like the length of the telescope is the sum of the focal lengths, the angular magnification is the objective focal length divided by the eyepiece focal length (or is it the other way around? I always forget), that kind of stuff.

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fermiboy
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Re: "Experimental" questions on the GRE?

Post by fermiboy » Wed Aug 20, 2008 2:32 pm

Why waste time learning everything about telescopes when at most there will be one question about them? Don't waste time learning a lot of specialized stuff that might or might not appear on the test. Just stick to the basics. If you come across a question you don't know how to answer just skip it. Nobody answers every question.

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dlenmn
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Re: "Experimental" questions on the GRE?

Post by dlenmn » Wed Aug 20, 2008 4:46 pm

fermiboy wrote:Why waste time learning everything about telescopes when at most there will be one question about them?
There was that one dumb telescope question on all the practice tests (something about resolving two stars x radians apart), and I memorized the relevant formula (it was really just one thing divided by another) and then it wasn't even on the bloody test. Talk about a let down. Hopefully they've had the good sense to remove telescope questions once and for all (Dammit ETS, I'm a physics major, not a astronomy major!).

a bucket
Posts: 60
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Re: "Experimental" questions on the GRE?

Post by a bucket » Thu Aug 21, 2008 11:40 am

Maybe they'll get rid of that damned positronium as well. :P



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