Errors in practice GRE test
Errors in practice GRE test
http://www.princeton.edu/~jdpeters/docs/ETS_extra.pdf
I think the answer to Q2 should be 1/3, not 3. What do you think?
I also don't see why you can't choose A for Q30. The hyperfine interaction of a spin-1/2 nucleus with j = 3/2 gives 3 states
f = i + j,... |i - j| = 2, 1, 0
I don't see why choice B is any better.
I think the answer to Q2 should be 1/3, not 3. What do you think?
I also don't see why you can't choose A for Q30. The hyperfine interaction of a spin-1/2 nucleus with j = 3/2 gives 3 states
f = i + j,... |i - j| = 2, 1, 0
I don't see why choice B is any better.
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Re: Errors in practice GRE test
for question 2noospace wrote:http://www.princeton.edu/~jdpeters/docs/ETS_extra.pdf
I think the answer to Q2 should be 1/3, not 3. What do you think?
I also don't see why you can't choose A for Q30. The hyperfine interaction of a spin-1/2 nucleus with j = 3/2 gives 3 states
f = i + j,... |i - j| = 2, 1, 0
I don't see why choice B is any better.
http://www.physicsgre.com/viewtopic.php?f=19&t=2618
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Re: Errors in practice GRE test
Then you have never heard of nuclear hyperfine interaction. This question is pretty easy but it can easily confuse somebody who does not know the phenomenon.blackcat007 wrote:noospace wrote:http://www.princeton.edu/~jdpeters/docs/ETS_extra.pdf
I think the answer to Q2 should be 1/3, not 3. What do you think?
I also don't see why you can't choose A for Q30. The hyperfine interaction of a spin-1/2 nucleus with j = 3/2 gives 3 states
f = i + j,... |i - j| = 2, 1, 0
I don't see why choice B is any better.
Physics_auth
Re: Errors in practice GRE test
Hi physics_auth,
Okay so what am I missing?
Okay so what am I missing?
Re: Errors in practice GRE test
Ahh, right. How could I miss that?blackcat007 wrote:for question 2noospace wrote:http://www.princeton.edu/~jdpeters/docs/ETS_extra.pdf
I think the answer to Q2 should be 1/3, not 3. What do you think?
I also don't see why you can't choose A for Q30. The hyperfine interaction of a spin-1/2 nucleus with j = 3/2 gives 3 states
f = i + j,... |i - j| = 2, 1, 0
I don't see why choice B is any better.
http://www.physicsgre.com/viewtopic.php?f=19&t=2618
Thanks.
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Re: Errors in practice GRE test
noospace wrote:Ahh, right. How could I miss that?blackcat007 wrote:for question 2noospace wrote:http://www.princeton.edu/~jdpeters/docs/ETS_extra.pdf
I think the answer to Q2 should be 1/3, not 3. What do you think?
I also don't see why you can't choose A for Q30. The hyperfine interaction of a spin-1/2 nucleus with j = 3/2 gives 3 states
f = i + j,... |i - j| = 2, 1, 0
I don't see why choice B is any better.
http://www.physicsgre.com/viewtopic.php?f=19&t=2618
Thanks.
To stimulate you to search and find which is the correct answer, see page 613 of "Introductory Nuclear physics" by Kenneth.S.Krane. There you will learn why (B) is correct.
Physics_auth
Re: Errors in practice GRE test
Okay thanks for your help. But I don't see why you're giving me a reference to point out an arithmetic error quite frankly.
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Re: Errors in practice GRE test
It is not an arithmetic error. I made the reference to this book to stimulate you to read carefully the phenomenon and then see clearly why (B) is correct. If the whole matter was an arithmetic error, I would have written the answer, since it is requires a few minutes and a few lines ... . Is that clear? If you read it from a source you will definitely understand what is going on and you will not get confused about this matter in case you see a relative question in the test. The source I mentioned is enough to give you a clear undestanding.noospace wrote:Okay thanks for your help. But I don't see why you're giving me a reference to point out an arithmetic error quite frankly.
Physics_auth
Re: Errors in practice GRE test
Hi physics_auth,
As far as I can tell, this is simply a matter of realizing that spin-1 and spin 3/2 is the only combination that gives three states, which as I said, is an arithmetic error on my part.
I really think you are making a big deal out of nothing.
As far as I can tell, this is simply a matter of realizing that spin-1 and spin 3/2 is the only combination that gives three states, which as I said, is an arithmetic error on my part.
I really think you are making a big deal out of nothing.
Re: Errors in practice GRE test
physics_auth
Can't you just use the fact that 3/2 + 1 is the only combination which gives 3 states?
Can't you just use the fact that 3/2 + 1 is the only combination which gives 3 states?
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Re: Errors in practice GRE test
This is exactly what I am implying ... that from the combination alone you cannot be sure; there is some kind of convention in the experimental method as to which result of the combination to keep so as to be able to find the spin by the number of lines ... and this explains why I mentioned a source to look at. For example, in a situation of different spins ... the number of lines gives the atom's spin not the nucleus' one (see Krane if you don't mind).noospace wrote:physics_auth
Can't you just use the fact that 3/2 + 1 is the only combination which gives 3 states?
Ok?
Physics_auth
Re: Errors in practice GRE test
Okay, I'll try and have a look today. The problem is I don't have that book handy. I still don't see why my combination of angular momenta method isn't sufficient though.
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Re: Errors in practice GRE test
I will try to give a brief explanation if I have time, in this post ... because other members may be interested.noospace wrote:Okay, I'll try and have a look today. The problem is I don't have that book handy. I still don't see why my combination of angular momenta method isn't sufficient though.