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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE => VCE Physics => Topic started by: melodrama on November 14, 2007, 12:34:57 pm

Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 12:34:57 pm
Post answers here. I wrote them on my formula sheet but the ladies TOOK IT AWAY. :(:(:(
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 12:39:36 pm
off the top of my head, i remember:

ELECTRIC POWER
1.6 newtons up
Field = 5.0x10^-3 Tesla
EMF = 30V
Frequency = 12.5 Hz
RMS Voltage = 57 V
C (the one where the amplitude got bigger and period got smaller)
2.5 A, 11 V, 2.2 V, 6W, 5.5W, 5.5W

LIGHT
Work function = 2.0eV
EK = 0.9eV
Transition goes from n=6 to n=something... it was the 13.2 to the 10.2 level
Velocity = 2.0x10^3m/s
Neutron diffracts slightly, though lambda/w<1, it was in same order of magnitude
Laser: B (wider gap = less diffraction, so that it's more bunched up)

SOUND
Out of phase, destructive interference, intensity
Frequency = 170Hz
Next Frequency = 510Hz
Intensity = 1.0x10^-6Wm^-2
C (8:1)
B (54dB)
Title: Exam 2 Answer Thread
Post by: root on November 14, 2007, 01:03:26 pm
Nice, think i got all those answers.
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:07:13 pm
Quote from: "Spirited Sloth"
off the top of my head, i remember:

ELECTRIC POWER
1.6 newtons up
Field = 5.0x10^-3 Tesla
EMF = 30V
Frequency = 12.5 Hz
RMS Voltage = 57 V
C (the one where the amplitude got bigger and period got smaller)

LIGHT
Work function = 2.0eV
EK = 0.9eV
Transition goes from n=6 to n=something... it was the 13.2 to the 10.2 level
Velocity = 2.0x10^3m/s

Laser: B (wider gap = less diffraction, so that it's more bunched up)

SOUND
Out of phase, destructive interference, intensity
Frequency = 170Hz
Next Frequency = 510Hz
Intensity = 1.0x10^6Wm^-2
C (8:1)
B (54dB)


i got 9580 ms or something for the speed  :?

FUCK i also said they wouldn't diffract but i realise now they would arghhh
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:10:15 pm
also what did people get for the Q for increasing slit width

i chose graph C, becuase the pattern would get larger? there would be no change in spacing as its slit 'width' but people are saying it gets thinner
Title: Exam 2 Answer Thread
Post by: boulos90 on November 14, 2007, 01:11:39 pm
Intensity in sound was 1x10^-6 i think
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:13:46 pm
LOL yep. sorry, 1.0x10^6 would explode your ears.
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:20:40 pm
according to this Q (neap 2006)

(http://i71.photobucket.com/albums/i127/retroflector/sdsdsdsdssssss.jpg)

a larger slit width has a larger pattern, and smaller width has a smaller pattern (note: spacing is still the same) which should give the answer C on our exam
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:22:24 pm
but when you increase gap width, you increase w and thus ratio wavelength/w decreases and there's less diffraction, meaning that it'll bunch up... i dunno. i said C initially but i changed my mind.
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 01:25:28 pm
I found that one tricky, but ended up putting B.
Title: Exam 2 Answer Thread
Post by: ___ on November 14, 2007, 01:26:48 pm
since distancebetweenbands = (length * lambda) / widthofslit , and widthofslit increases, the distance between the bands will be smaller (ie, more bunched up)
Title: Exam 2 Answer Thread
Post by: Matt89 on November 14, 2007, 01:27:30 pm
Quote from: "Spirited Sloth"
2.5 A, 11 V, 2.2 V, 6W, 5.5W, 5.5W


Totally f***ed that one up. I stuffed up the calculation of the power, so I lost 3 marks  :(
Title: Exam 2 Answer Thread
Post by: v2shan on November 14, 2007, 01:28:34 pm
Quote from: "maxleng"
according to this Q (neap 2006)

a larger slit width has a larger pattern, and smaller width has a smaller pattern (note: spacing is still the same) which should give the answer C on our exam


sry, but the answer for that is wrong, i checked with my tutor a few weeks ago

n spirited i got the same cept for the 2nd light q, were u meant to get the h value from the graph as well, cos i just used the 6.63E-34..... ooh i think thats y it was 3 marks, was it 3marks?... oh n u have very good memory
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:28:40 pm
i hate those power lines questions; they're so bitchy
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:28:49 pm
Quote from: "Matt89"
Quote from: "Spirited Sloth"
2.5 A, 11 V, 2.2 V, 6W, 5.5W, 5.5W


Totally f***ed that one up. I stuffed up the calculation of the power, so I lost 3 marks  :(


woah i got diff answers...i think cos i used a resistance of 4 ohms SHIT!!!!
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:29:30 pm
Quote from: "v2shan"
Quote from: "maxleng"
according to this Q (neap 2006)

a larger slit width has a larger pattern, and smaller width has a smaller pattern (note: spacing is still the same) which should give the answer C on our exam


sry, but the answer for that is wrong, i checked with my tutor a few weeks ago

n spirited i got the same cept for the 2nd light q, were u meant to get the h value from the graph as well, cos i just used the 6.63E-34..... ooh i think thats y it was 3 marks, was it 3marks?... oh n u have very good memory


what a load of SHIT ahhhhh fuck you NEAP
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 01:30:06 pm
I'm gonna do the impossible and disagree with Mel for some of those power loss questions.   :x
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:30:39 pm
were you supposed to?
Title: Exam 2 Answer Thread
Post by: ___ on November 14, 2007, 01:31:15 pm
i used total resistance of 4ohms  :?

everyone else i talked to after the exam did too
Title: Exam 2 Answer Thread
Post by: AhaShake on November 14, 2007, 01:31:18 pm
I am going to agree with Ahmad. You had to remember the resistance was 4 ohm not 2 ohm.
I got nervous there, without Ahmad questioning it on the first page. But good.
Title: Exam 2 Answer Thread
Post by: Matt89 on November 14, 2007, 01:31:19 pm
Quote from: "maxleng"
Quote from: "Matt89"
Quote from: "Spirited Sloth"
2.5 A, 11 V, 2.2 V, 6W, 5.5W, 5.5W


Totally f***ed that one up. I stuffed up the calculation of the power, so I lost 3 marks  :(


woah i got diff answers...i think cos i used a resistance of 4 ohms SHIT!!!!


I used resistance of 4 ohms, but i accidentally used 2.5 A instead of 0.5 A
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:31:59 pm
what i did was find the frequency from the graph and i got 0.9eV... it'll be about +/- 0.1 depending on how you draw your graph i guess.

omg. ahmad disagrees with me. damn, -1934871394871 marks for me.
Title: Exam 2 Answer Thread
Post by: v2shan on November 14, 2007, 01:32:14 pm
i dunno w/e 2 marks to conservative, practical was all good but what bout theory, some tricky q's i reckon e.g. the hydrogen emission one
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 01:33:26 pm
Yeah, so I got something like (can't remember very well):

2.5 A, 10 V, 2 V

6 W, 5 W, 5 W
Title: Exam 2 Answer Thread
Post by: boulos90 on November 14, 2007, 01:33:43 pm
2.5 A, 11 V, 2.2 V, 6W, 5.5W, 5.5W

i got 2.5A, 10V, 2.0V 6W, 5W, and 5W i think...

I took resistance in power lines to be 4ohms
Title: Exam 2 Answer Thread
Post by: hifer on November 14, 2007, 01:33:53 pm
Quote from: "Spirited Sloth"
but when you increase gap width, you increase w and thus ratio wavelength/w decreases and there's less diffraction, meaning that it'll bunch up... i dunno. i said C initially but i changed my mind.


Yup, it's definitely B for that one
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:34:08 pm
AH THAT'S NOT FAIR. NEAP HAD A SIMILAR QUESTION AND THEY USED 2.0 OHMS. FUCK YOU NEAP.
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:34:11 pm
i said sunlight is missing the energy of hydrogen since it uses it, hence when passed through a prism the spectrum of hydrogen will not be seen


i dont think its totally right tho  :?
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:34:39 pm
Quote from: "Spirited Sloth"
AH THAT'S NOT FAIR. NEAP HAD A SIMILAR QUESTION AND THEY USED 2.0 OHMS. FUCK YOU NEAP.


LOL lets go burn down NEAP head quarters  :twisted:  :twisted:  :twisted:
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 01:34:56 pm
k im gonna go chem now. mods, edit my answers if you like. unless... you contradict me ... LOL.
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 01:36:02 pm
For hydrogen question:

* Hydrogen is in space between Sun and Earth.
* As light passes through them some wavelengths corresponding to difference in energy levels are absorbed.
* Hence the other wavelengths are passed through.
* Note resemblance between emission spectrum of hydrogen and absorption.

Something on the lines of that, I wrote more.. but can't remember.
Title: Exam 2 Answer Thread
Post by: boulos90 on November 14, 2007, 01:36:31 pm
i got 1.1 for the one we had to read from the graph, that should be right, yeh?? :?
Title: Exam 2 Answer Thread
Post by: hifer on November 14, 2007, 01:37:14 pm
Quote from: "maxleng"
i said sunlight is missing the energy of hydrogen since it uses it, hence when passed through a prism the spectrum of hydrogen will not be seen


i dont think its totally right tho  :?



I think it's coz the hydrogen in space n the atmosphere absorbs the wavelengths.. that's why they are missing in the spectrum we measure from the sun..

Wavelength in emission spectrums = wavelengths absorbed coz they correspond to the same energy
Title: Exam 2 Answer Thread
Post by: boulos90 on November 14, 2007, 01:37:29 pm
Quote from: "Ahmad"
For hydrogen question:

* Hydrogen is in space between Sun and Earth.
* As light passes through them some wavelengths corresponding to difference in energy levels are absorbed.
* Hence the other wavelengths are passed through.
* Note resemblance between emission spectrum of hydrogen and absorption.

Something on the lines of that, I wrote more.. but can't remember.


Meh, ill probably lose 1 mark for that 1, how much was it out of?
Title: Exam 2 Answer Thread
Post by: bilgia on November 14, 2007, 01:45:02 pm
Quote from: "Ahmad"
Yeah, so I got something like (can't remember very well):

2.5 A, 10 V, 2 V

6 W, 5 W, 5 W


PHEW.! i did pretty well
Title: Exam 2 Answer Thread
Post by: bilgia on November 14, 2007, 01:45:39 pm
Quote from: "boulos90"
i got 1.1 for the one we had to read from the graph, that should be right, yeh?? :?



 i did that
Title: Exam 2 Answer Thread
Post by: ___ on November 14, 2007, 01:48:12 pm
im pretty sure anywhere between 0.9 - 1.1 will be accepted..

i personally put 1.0
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 01:48:45 pm
it should be .9 b/c its a freq of 7.5 which is below 1... i really dont see how it can be 1.1 cos if u used the formula to work out  the freq there is no way u can get over 1 (1 should be fine) but over it is pushing it. mainly because the line you drew matched up really well with the points.

if there tight they will not give you 1.1 (which they might be cos it was pretty easy) so i dont know...

what did people say for the last Qs on light

i had:

continous
discrete

filament: acc + dec of electrons (thermal excitation)
discharge tube: electrons excited then drop down releasing energy = light
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 01:50:29 pm
I put 1.0, looked about that on my graph. And yes, I pretty much said what you did for the light questions.
Title: Exam 2 Answer Thread
Post by: AkirA on November 14, 2007, 01:52:52 pm
I agree with Ahmad.
Title: Exam 2 Answer Thread
Post by: bilgia on November 14, 2007, 01:53:52 pm
damn lost at least 3marks so far
Title: Exam 2 Answer Thread
Post by: avogarbro on November 14, 2007, 02:03:52 pm
Ahmad, your answers look similar to mine. (but im not certain) i remember considering a voltage drop in my power line question.

Vdrop was like 4 *.5 = 2 V drop across the power lines wasn't it?
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 02:04:19 pm
Quote from: "avogarbro"
Ahmad, your answers look similar to mine. (but im not certain) i remember considering a voltage drop in my power line question.

Vdrop was like 4 *.5 = 2 V drop across the power lines wasn't it?


i got that
Title: Exam 2 Answer Thread
Post by: mtyp on November 14, 2007, 02:06:24 pm
what was the answer to the induced current thing? about current flowing momentarily/continuously from X to Y / Y to X?
Title: Exam 2 Answer Thread
Post by: avogarbro on November 14, 2007, 02:07:48 pm
According to that the voltage at the end of the powerlines (where the transformer was) should be 10V (12V-2V) . I remember the transformer ratio was like 5:1 (primary to secondary). So at the globe the voltage was 2V.
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 02:09:31 pm
Quote from: "avogarbro"
Ahmad, your answers look similar to mine. (but im not certain) i remember considering a voltage drop in my power line question.

Vdrop was like 4 *.5 = 2 V drop across the power lines wasn't it?


Yeah that's what I got, didn't I?  :? lol
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 02:15:01 pm
Quote from: "mtyp"
what was the answer to the induced current thing? about current flowing momentarily/continuously from X to Y / Y to X?


i chose B,

it was either A or B becuase it wasnt continuous
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 02:15:49 pm
I chose B too.
Title: Exam 2 Answer Thread
Post by: mtyp on November 14, 2007, 02:19:38 pm
phew!! there's another question about 2000 A, 2 m and some value of magnetic field, i got a magnitude of 1.6 N, how about the direction? and for one of the multiple choice questions on light and matter, where the slit width increased, what was the answer for that?
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 02:20:28 pm
:(:(:( STUPID NEAP. it's not fair; i would have done it ahmad's way if it weren't for neap convincing me otherwise. -4 marks for that then. GAHHH.
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 02:21:28 pm
Cheer up mel. You'll probably get some consequential marks.
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 02:22:10 pm
Quote from: "mtyp"
phew!! there's another question about 2000 A, 2 m and some value of magnetic field, i got a magnitude of 1.6 N, how about the direction? and for one of the multiple choice questions on light and matter, where the slit width increased, what was the answer for that?


The general consensus is B.
Title: Exam 2 Answer Thread
Post by: avogarbro on November 14, 2007, 02:23:32 pm
To ensure that we do well in our remaining exams is it best to forget about the exams that have finished? Since discussing about physics will make some people frustrated (more so if you are high achiever). I believe the best option is to think positively say to yourself that the exam is finished and move on (Although the temptation to know how much you got right is too tempting for    most)
Title: Exam 2 Answer Thread
Post by: Ahmad on November 14, 2007, 02:25:36 pm
Well, I don't think it's right to brood over your mistakes for too long, although it's natural to to some extent.

I'm slightly disheartened, but if we all brood for too long we'll not be able to focus on chemistry and specialist. Haha  8)
Title: Answers
Post by: kaney1234 on November 14, 2007, 02:37:53 pm
Here are my answers:
Area of Study 1: 3. 1.6 up
4. B
6. 5*10^-3
7. 30 V
8. 12.5 hz
9. 56.57V
10. C
11. i) 2.5 A, ii)10v, iii)2v
12. i) 6, ii)5, iii)5
14. B
AOS2 - light
1.2.1
2. 0.9
3. particle
4. 1985ms-1
5. Yes diffraction the gap is in the same order as the debogle wavelength
6. B
7. 2.86
8. n=6 to n=2
10. i) wrote broad spectrum. but explained that it is a continuous spectrum. any chance of a mark?

Sound-
2. 3.4 m (did you just have to assume sound traveled at 340ms
3. 170 hz
5. D
8. 1*10^-6
9.C
10. B

think pretty well overall. If I dropped two in midyear and like two today and being top ranked in our sacs what score will i be looking at?
Title: Exam 2 Answer Thread
Post by: Galelleo on November 14, 2007, 02:56:06 pm
Quote from: "Spirited Sloth"

2.5 A, 11 V, 2.2 V, 6W, 5.5W, 5.5W



thats wrong, it was 5w 5w... only 10v got past the power lines because their total resistance was 4 ohms.

Quote from: "Ahmad"
I found that one tricky, but ended up putting B.


I do too... you increase gap width, you decrease the fringe spacing.

Quote from: "Ahmad"
For hydrogen question:

* Hydrogen is in space between Sun and Earth.
* As light passes through them some wavelengths corresponding to difference in energy levels are absorbed.
* Hence the other wavelengths are passed through.
* Note resemblance between emission spectrum of hydrogen and absorption.

Something on the lines of that, I wrote more.. but can't remember.


I said... "We can see from hte hydrogen emission spectra that hydrogen atoms have energy elvels at (the given wavelengths) ... the suns absorption spectra shows gaps in the same wavelength, so we cna safely assume that the photons of that energy are absorbed by the hydrogen on/around the sun.

Quote from: "___"
im pretty sure anywhere between 0.9 - 1.1 will be accepted..

i personally put 1.0


I doubt theyll take .9 or 1.1

you got 1.1 if you used plancks constant, and the question specifically said FROM THE GRAPH... and the graph was pretty bovious that 7.5 lined up with 1.

Quote from: "kaney1234"

5. Yes diffraction the gap is in the same order as the debogle wavelength

2. 3.4 m (did you just have to assume sound traveled at 340ms


The diffraction ratios was 2/3, You had to say that there would be some diffraction but not as significant.


It told you at the top that sound was 340.
Title: Re: Answers
Post by: boulos90 on November 14, 2007, 02:58:33 pm
Quote from: "kaney1234"
Here are my answers:
Area of Study 1: 3. 1.6 up
4. B
6. 5*10^-3
7. 30 V
8. 12.5 hz
9. 56.57V
10. C
11. i) 2.5 A, ii)10v, iii)2v
12. i) 6, ii)5, iii)5
14. B
AOS2 - light
1.2.1
2. 0.9
3. particle
4. 1985ms-1
5. Yes diffraction the gap is in the same order as the debogle wavelength
6. B
7. 2.86
8. n=6 to n=2
10. i) wrote broad spectrum. but explained that it is a continuous spectrum. any chance of a mark?

Sound-
2. 3.4 m (did you just have to assume sound traveled at 340ms
3. 170 hz
5. D
8. 1*10^-6
9.C
10. B

think pretty well overall. If I dropped two in midyear and like two today and being top ranked in our sacs what score will i be looking at?


47-48 raw i would think
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 02:59:35 pm
if your graph was drawn accurately 7.5x10^14 Hz lined up just below 1 ie .9
Title: Exam 2 Answer Thread
Post by: Galelleo on November 14, 2007, 03:01:19 pm
mine hit the middle. Mabe the important thing was not to show calculations, (i did it, then crossed all my workings out ) lol
Title: Exam 2 Answer Thread
Post by: abcat on November 14, 2007, 03:24:24 pm
Quote from: "Galelleo"

Quote from: "Ahmad"
For hydrogen question:

* Hydrogen is in space between Sun and Earth.
* As light passes through them some wavelengths corresponding to difference in energy levels are absorbed.
* Hence the other wavelengths are passed through.
* Note resemblance between emission spectrum of hydrogen and absorption.

Something on the lines of that, I wrote more.. but can't remember.


I said... "We can see from hte hydrogen emission spectra that hydrogen atoms have energy elvels at (the given wavelengths) ... the suns absorption spectra shows gaps in the same wavelength, so we cna safely assume that the photons of that energy are absorbed by the hydrogen on/around the sun.


I wrote something very similar, but I didn't actually understand/believe it. It seemed the logical answer but I can't really get my head around it

If photons with that energy were absorbed by the Hydrogen, why did they show up as bright spots on the Hydrogen emission spectra?

The mercury vapour questions threw me a fair bit, I think I wrote that they give off mainly in the Ultra-Violet range. As for how the light is created I think I just took a wild stab heheh.
Title: Exam 2 Answer Thread
Post by: ___ on November 14, 2007, 03:34:32 pm
i wrote broad spectrum instead of continuous ><

i thought they were one and the same??????
Title: Exam 2 Answer Thread
Post by: rox-n-bones on November 14, 2007, 03:53:58 pm
Quote
i got 9580 ms or something for the speed  :?


i got something like that as well? i made soo many stupid mistakes it's not funny oh well. TODAY WAS MY LAST EXAM WOOOHOOO
Title: Exam 2 Answer Thread
Post by: Galelleo on November 14, 2007, 04:24:45 pm
Quote from: "abcat"
Quote from: "Galelleo"

Quote from: "Ahmad"
For hydrogen question:

* Hydrogen is in space between Sun and Earth.
* As light passes through them some wavelengths corresponding to difference in energy levels are absorbed.
* Hence the other wavelengths are passed through.
* Note resemblance between emission spectrum of hydrogen and absorption.

Something on the lines of that, I wrote more.. but can't remember.


I said... "We can see from hte hydrogen emission spectra that hydrogen atoms have energy elvels at (the given wavelengths) ... the suns absorption spectra shows gaps in the same wavelength, so we cna safely assume that the photons of that energy are absorbed by the hydrogen on/around the sun.


I wrote something very similar, but I didn't actually understand/believe it. It seemed the logical answer but I can't really get my head around it

If photons with that energy were absorbed by the Hydrogen, why did they show up as bright spots on the Hydrogen emission spectra?

The mercury vapour questions threw me a fair bit, I think I wrote that they give off mainly in the Ultra-Violet range. As for how the light is created I think I just took a wild stab heheh.


the hydrogen emission spectra was only there to show us that hydrogen absorbs those frequencies.

Initially, theyre absorbed by the hydrogen. which means the abrosption spectra from the sun has gaps tehre... then (later on, not relevant to example) the energy in that hydrogen atmo would have igven off the same photos. which is why the hydrogen emission spectra had them as colours.
Title: Exam 2 Answer Thread
Post by: Galelleo on November 14, 2007, 04:26:01 pm
continuous isnt hte same as broad... broad isnt definite, it just suggests that theres a larger spectra... (rather than all frequencies of light) ... i think :S

but yeh, you were suppsoed to say that light bulb gives a continuous spectrum, and vapour lamp gives a discrete spectrum... thats the question i lost marks on :( :( :(

after that the principles were thermal motion of electrons and photon emission (respectively).
Title: Exam 2 Answer Thread
Post by: melodrama on November 14, 2007, 04:50:20 pm
OMG that was the word!!!! i was trying to think of the word opposite to continuous (discrete) but i gave up and called it a "specific and unique emission spectra) LOL.
Title: Exam 2 Answer Thread
Post by: maxleng on November 14, 2007, 05:02:28 pm
jack would be disappointed, he spent 2 lessons on discrete and continuous!!  :P
Title: Exam 2 Answer Thread
Post by: Collin Li on November 14, 2007, 05:02:31 pm
Quote from: "Spirited Sloth"
OMG that was the word!!!! i was trying to think of the word opposite to continuous (discrete) but i gave up and called it a "specific and unique emission spectra) LOL.


AHAHAHAHA. I'm bagging you about that for the rest of your life, and I'm telling DW.
Title: Exam 2 Answer Thread
Post by: Galelleo on November 14, 2007, 05:35:52 pm
lol , i had a complete brain fart on that question... didnt know the answer.

I said something like ... incoherent spectrum and emission spectrum.
Title: Exam 2 Answer Thread
Post by: Daniel15 on November 14, 2007, 05:42:58 pm
Blah
I did what I usually do and made some stupid mistakes
Looks like no study score of 40 for me...
>_<

Lolz, for the question with the hydrogen spectra and the dark bands, I couldn't answer it (I really had no idea what that question was talking about :P), and wrote "It gets absorbed" as an afterthought (just as they said "Pens down"). Is it possible that I could still get a mark for that?  :lol:


Quote from: "Ahmad"
Yeah, so I got something like (can't remember very well):

2.5 A, 10 V, 2 V

6 W, 5 W, 5 W

Yep, that's what I got to. You need to use the total resistance of 4Ω, not the resistance of a single wire (2Ω).

Quote
im pretty sure anywhere between 0.9 - 1.1 will be accepted..

i personally put 1.0

I put 1.0 as well.
Title: Exam 2 Answer Thread
Post by: Galelleo on November 14, 2007, 06:28:03 pm
lol i finished half an hour early

walked out around 1 and went for some lunch :P, no guilt lol.... even had time to check my answers... simple, straight forward questions...my favorite exam so far
Title: Exam 2 Answer Thread
Post by: boulos90 on November 15, 2007, 12:35:32 pm
Itute solutions are upp!!

Damn for Question 2 electric power did we have to draw the magnetic field lines that wernt coming from the magnet?? coz i didnt:(