Post by: StringFever on November 11, 2009, 01:16:17 pm
Was it as easy as the Unit 3 catastrophe?
:)
PS. I don't do Physics, but I'm curious to know! :)
Post by: simpak on November 11, 2009, 01:24:48 pm
It doesn't finish for another...6 minutes though, right?
Post by: hyperblade01 on November 11, 2009, 01:31:16 pm
89.5/90 vs. 75/90
Post by: KeyMan on November 11, 2009, 01:44:16 pm
Post by: homghomg1 on November 11, 2009, 01:45:58 pm
i thought it was a fairer standard than unit 3, a little harder and much more time consuming cos of all the explanation questions
Post by: Damo17 on November 11, 2009, 01:51:18 pm
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.
Post by: dejan91 on November 11, 2009, 01:54:22 pm
I think the cut off A+ will be lower than unit 3, seeing as they'll be able to take off marks easily for the written explanations.
Post by: Fireworks on November 11, 2009, 01:56:52 pm
Far too much theory, and as stated, not enough calculations.
I've either done rather well, or horribly depending on what
the examiner thinks of my worded answers.
Post by: almostatrap on November 11, 2009, 01:58:00 pm
Post by: Damo17 on November 11, 2009, 01:59:01 pm
I think the cut off A+ will be lower than unit 3, seeing as they'll be able to take off marks easily for the written explanations.
Yeah, I would say high 70's to low 80's A+ cut off. Although many of the calculation based questions were easy, the explanations that took over 'Interactions of Light and Matter' would be where many people will lose alot of marks.
Post by: dejan91 on November 11, 2009, 02:04:14 pm
I've either done rather well, or horribly depending on what
the examiner thinks of my worded answers.
This basically sums the exam up.
Post by: toomoo on November 11, 2009, 02:05:59 pm
I would say it was almost as easy as the unit 3 exam.
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.
Isnt TT a chick?
Post by: Edmund on November 11, 2009, 02:07:51 pm
Post by: Damo17 on November 11, 2009, 02:16:07 pm
I would say it was almost as easy as the unit 3 exam.
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.
Isnt TT a chick?
We think Male, but tests are inconclusive.
Post by: toomoo on November 11, 2009, 02:17:57 pm
Maybe one day.
Post by: avram_grant on November 11, 2009, 02:18:36 pm
Post by: dylanru on November 11, 2009, 02:18:54 pm
Post by: Slappo on November 11, 2009, 02:19:04 pm
haha it was good exam, defs harder than unit 3.. but if u know ur theory back to front especially with section 2 or with a decent cheat sheet.. not that hard =D
Post by: nels on November 11, 2009, 02:20:31 pm
did anyone else get a massive number for the energy of the photon? like 8000eV? i was getting very worried.
Post by: m.hudson.1990 on November 11, 2009, 02:22:21 pm
Post by: avram_grant on November 11, 2009, 02:23:21 pm
Post by: toomoo on November 11, 2009, 02:24:10 pm
Post by: m.hudson.1990 on November 11, 2009, 02:24:46 pm
Post by: avram_grant on November 11, 2009, 02:29:24 pm
Post by: catweazle on November 11, 2009, 02:29:45 pm
yeah that was it...just under 9000 was what i meant to say
8.9*10^3
Post by: catweazle on November 11, 2009, 02:30:09 pm
does anyone have suggested solutions for entire exam?
Itute will have it up soon
Post by: avram_grant on November 11, 2009, 02:31:14 pm
does anyone have suggested solutions for entire exam?
Itute will have it up soon
gratsi
Post by: Gloamglozer on November 11, 2009, 02:32:39 pm
Post by: nels on November 11, 2009, 02:34:00 pm
we didnt have to put it in sig figs did we :Syeah that was it...just under 9000 was what i meant to say
8.9*10^3
apart from the question where we were required to.
Post by: avram_grant on November 11, 2009, 02:34:23 pm
Post by: m.hudson.1990 on November 11, 2009, 02:35:32 pm
Post by: Murph#3 on November 11, 2009, 02:37:36 pm
Post by: methodsboy on November 11, 2009, 02:38:06 pm
Post by: methodsboy on November 11, 2009, 02:38:46 pm
yep...498V..YAY!
10000W
Itransmission was 2A
remember to put resistance as 10ohms not 5ohms
Post by: THem on November 11, 2009, 02:39:08 pm
i just wrote 8875.43ev but same thing
Haha yea 8xxx eV?? Normally it's like just 1 digit. I thought I got it wrong ;D
Post by: avram_grant on November 11, 2009, 02:39:19 pm
i just wrote 8875.43ev but same thing
yeh you only have to do significant figures if they ask
Post by: Thurlz on November 11, 2009, 02:40:56 pm
i just wrote 8875.43ev but same thing
yeh you only have to do significant figures if they ask
Wooo ;)
Post by: Flaming_Arrow on November 11, 2009, 02:45:08 pm
nuff said
Post by: catweazle on November 11, 2009, 02:46:54 pm
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
Post by: avram_grant on November 11, 2009, 02:49:14 pm
light and matter Q6
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
yep
Post by: Over9000 on November 11, 2009, 02:49:20 pm
light and matter Q66e -15 and 1.5 (but for planks constant they will accept a large range of values within e-15)
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
Post by: methodsboy on November 11, 2009, 02:50:23 pm
yeplight and matter Q6
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
yep
what about the ave EMF? did u divide that time by 4?
Post by: Over9000 on November 11, 2009, 02:50:49 pm
Whahh? Serz?yeplight and matter Q6
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
yep
what about the ave EMF? did u divide that time by 4?
Post by: avram_grant on November 11, 2009, 02:51:35 pm
yeplight and matter Q6
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
yep
what about the ave EMF? did u divide that time by 4?
no
Post by: methodsboy on November 11, 2009, 02:52:06 pm
i took the point from fthres and another point. It's just finding the gradient...if u do methods or even further, you should be able to get that
Post by: methodsboy on November 11, 2009, 02:52:49 pm
hmm.. i had done a similar question to that in a trial and they divided the time by fouryeplight and matter Q6
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
yep
what about the ave EMF? did u divide that time by 4?
no
Post by: TrueTears on November 11, 2009, 02:53:16 pm
I spammed my cheat sheet :)
Post by: krzysiek on November 11, 2009, 02:53:21 pm
Post by: crappy on November 11, 2009, 02:53:37 pm
Post by: avram_grant on November 11, 2009, 02:54:12 pm
I didn't divide the time by four. It gave the time interval for 90 degree turn (which is what you usually take to find EMF)
yeh thats correct, they didnt give the period of one rotation, so you didnt have to divide by 4
Post by: methodsboy on November 11, 2009, 02:54:42 pm
no, i didnt divide it. although it had average in bolded, I thought I missed somethingDamn! oh well i should get at least 1 or 2 marks for that
Post by: krzysiek on November 11, 2009, 02:55:04 pm
Post by: methodsboy on November 11, 2009, 02:56:36 pm
Yes, the average part got the best of me. I assumed, because it was not a DC generator, but rather an AC generator that it produces a voltage at it's PEAK, hence, the value I got for EMF i thought was a peak value, and we all know average means Voltage / SQRT2 so I applied this to the answer to find the 'average' - I have no idea if that is what they wanted, but for three marks, I do think they wanted something more.Hence, my spontaneous decision to divide it by 4...
Post by: ayaz on November 11, 2009, 02:57:26 pm
000V was that right or did i make the mistake:(
Post by: TrueTears on November 11, 2009, 02:57:49 pm
Post by: naved_s9994 on November 11, 2009, 02:58:34 pm
yeplight and matter Q6
You had to calculate plancks constant and the stopping voltage.
Did anyone get 5E-15 and 1.5?
yep
what about the ave EMF? did u divide that time by 4?
no it already gave it in 90 degrees
Post by: avram_grant on November 11, 2009, 02:58:53 pm
498V 3 sig figs wasn't it?
yeh thats correct
Post by: moekamo on November 11, 2009, 02:59:12 pm
so average is when you use delta flux / delta time over a time period
Post by: TrueTears on November 11, 2009, 02:59:32 pm
Post by: naved_s9994 on November 11, 2009, 03:00:17 pm
Wow so much explain questions.
I spammed my cheat sheet :)
Id like to take this opportunity to thank you.
Except, I made a heck of ammendments...because of your answers were in written. I converted them
into dot points.
Post by: krzysiek on November 11, 2009, 03:00:23 pm
Yes, the average part got the best of me. I assumed, because it was not a DC generator, but rather an AC generator that it produces a voltage at it's PEAK, hence, the value I got for EMF i thought was a peak value, and we all know average means Voltage / SQRT2 so I applied this to the answer to find the 'average' - I have no idea if that is what they wanted, but for three marks, I do think they wanted something more.
I dont get why you divided it by 4? It have you the MAX flux, and it gave you the time for one quarter turn. To work out the induced emf, it is change in flux / change in time. In this case, it gave you the max flux, which is the change in flux for our purposes. The maximum EMF (peak) occurs when the flux goes from Max to 0, and this is in a one quarter turn, and it gave you the time for this.
In this sense, I believe you only use the max flux they gave you, and the time taken for one revolution. Then, from what I thought and it might be wrong, was that the value obtained was a PEAK value, as this is an AC generator not DC. So i divided the answer by the square root of 2 to get the AVG emf. I don't see where a four comes in to play ?
Hence, my spontaneous decision to divide it by 4...
Post by: crappy on November 11, 2009, 03:00:37 pm
Post by: arman on November 11, 2009, 03:00:49 pm
Post by: naved_s9994 on November 11, 2009, 03:01:37 pm
so what was the answer to that average voltage question.
you dont divide by 4, everything else is the same
Post by: almostatrap on November 11, 2009, 03:01:42 pm
Post by: TrueTears on November 11, 2009, 03:01:48 pm
I am what you want me to be :) LOLI would say it was almost as easy as the unit 3 exam.
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.
Isnt TT a chick?
We think Male, but tests are inconclusive.
Post by: avram_grant on November 11, 2009, 03:01:59 pm
so what was the answer to that average voltage question.
i got 3.6x10-4
Post by: naved_s9994 on November 11, 2009, 03:02:19 pm
i am sooo waiting for the solutions lol :P
Naa im alright..I know Ive done well :P HEHE
Post by: Over9000 on November 11, 2009, 03:02:25 pm
Btw, thanks TT for ur leet cheat sheetI am what you want me to be :) LOLI would say it was almost as easy as the unit 3 exam.
Electric power was easy as usual. The theory in light and matter was extremely easy (if you actually utilised parts of TT cheat sheet that he so kindly uploaded). Photonics had some easy MC, but I most likely got a few wrong that I guessed.
Isnt TT a chick?
We think Male, but tests are inconclusive.
Post by: TrueTears on November 11, 2009, 03:02:29 pm
Same here.so what was the answer to that average voltage question.
i got 3.6x10-4
Post by: crappy on November 11, 2009, 03:02:42 pm
so what was the answer to that average voltage question.
i got 3.6x10-4
oh sigh of relief. thanks legend
Post by: IntoTheNewWorld on November 11, 2009, 03:03:26 pm
I LOVE YOU TT FOR THE EPIC CHEAT SHEET
nuff said
+9000
it was so damn awesome
Post by: kdgamz on November 11, 2009, 03:03:50 pm
I LOVE YOU TT FOR THE EPIC CHEAT SHEET
nuff said
yes yes
Post by: m.hudson.1990 on November 11, 2009, 03:04:33 pm
Post by: blindman on November 11, 2009, 03:05:27 pm
but i'll still get marks for working and stuff yeah? and will i get consequential marks for the voltage difference questions because of this if everything else is right except the resistance?
Post by: avram_grant on November 11, 2009, 03:05:49 pm
Post by: crappy on November 11, 2009, 03:07:03 pm
anyone else also screwed for chem?
yep, right here.
Post by: dylanru on November 11, 2009, 03:08:03 pm
anyone else also screwed for chem?
yep, right here.
Post by: TrueTears on November 11, 2009, 03:08:38 pm
sooo screwedScrew Chem, Chem doesn't make sense.anyone else also screwed for chem?
yep, right here.
Post by: blindman on November 11, 2009, 03:09:04 pm
Post by: Over9000 on November 11, 2009, 03:09:29 pm
pretty good exam until i found out that the resistance was series and not parallel.Lol, blindhead.
but i'll still get marks for working and stuff yeah? and will i get consequential marks for the voltage difference questions because of this if everything else is right except the resistance?
Post by: avram_grant on November 11, 2009, 03:09:36 pm
Post by: arman on November 11, 2009, 03:10:08 pm
Post by: blindman on November 11, 2009, 03:10:33 pm
pretty good exam until i found out that the resistance was series and not parallel.Lol, blindhead.
but i'll still get marks for working and stuff yeah? and will i get consequential marks for the voltage difference questions because of this if everything else is right except the resistance?
lol..its blindman. so do physics assessors award consequential marks or not?
Post by: avram_grant on November 11, 2009, 03:10:45 pm
any help with my qn guys?
yeh you will only lose a mark or so - the rest will be marked consequentially, so you will only lose like a mark
Post by: Over9000 on November 11, 2009, 03:11:53 pm
Yes, u do get consequential.pretty good exam until i found out that the resistance was series and not parallel.Lol, blindhead.
but i'll still get marks for working and stuff yeah? and will i get consequential marks for the voltage difference questions because of this if everything else is right except the resistance?
lol..its blindman. so do physics assessors award consequential marks or not?
Post by: blindman on November 11, 2009, 03:13:50 pm
Post by: avram_grant on November 11, 2009, 03:15:50 pm
Post by: Over9000 on November 11, 2009, 03:16:53 pm
did you guys get 'up' for the direciton of the forceAlmost
Post by: /0 on November 11, 2009, 03:17:33 pm
did you guys get 'up' for the direciton of the force
yeah in the last 5 seconds... they tried to hide that question
Post by: TrueTears on November 11, 2009, 03:17:47 pm
LOL, so you drew the line going up but then curved it off thus almost directly upwards ;)did you guys get 'up' for the direciton of the forceAlmost
Post by: Over9000 on November 11, 2009, 03:18:47 pm
did you guys get 'up' for the direciton of the force
yeah in the last 5 seconds... they tried to hide that question
Lucky I saw it in reading timedid you guys get 'up' for the direciton of the force
yeah in the last 5 seconds... they tried to hide that question
Post by: Over9000 on November 11, 2009, 03:19:10 pm
Yeh, lol.LOL, so you drew the line going up but then curved it off thus almost directly upwards ;)did you guys get 'up' for the direciton of the forceAlmost
Post by: sachinmachin on November 11, 2009, 03:20:40 pm
did you guys get 'up' for the direciton of the force
FML!!!!, i didnt even see that question. easiest 2 marks gone....yes the force would be up (clockwise).
Post by: avram_grant on November 11, 2009, 03:21:00 pm
Post by: TrueTears on November 11, 2009, 03:21:28 pm
did anyone get 496nm for the wavelength?Yeah.
Post by: julianpeiriez on November 11, 2009, 03:25:27 pm
Post by: Over9000 on November 11, 2009, 03:27:01 pm
how did you guys go in the last Q for light section. (quantum energy Q)Certain frequencies needed for standing wave, this can be compared to the specific shell levels (in terms of energy) that electrons can exist in.
Post by: avram_grant on November 11, 2009, 03:27:28 pm
how did you guys go in the last Q for light section. (quantum energy Q)
i just copied from my cheet sheet, lol
Post by: Over9000 on November 11, 2009, 03:27:53 pm
Fkn cheaterhow did you guys go in the last Q for light section. (quantum energy Q)
i just copied from my cheet sheet, lol
Post by: /0 on November 11, 2009, 03:30:19 pm
Post by: tommyk221 on November 11, 2009, 03:37:51 pm
hey guys for the question in area of studies 1 core the transformers question it goes correct to 3 decimal places i got 496.
000V was that right or did i make the mistake:(
The question asked for three significant figures, not three decimal places.
So the answer was 498V.
Post by: kev0 on November 11, 2009, 03:39:29 pm
I missed the sneak question as well. I remember telling myself don't forget to arrow the shit, but I did.
Post by: NE2000 on November 11, 2009, 03:43:51 pm
did anyone get 496nm for the wavelength?Yeah.
Did you bother drawing a diagram? They left such a massive space but it didn't really require that did it :S. Also it was only 2 marks.
My view of exam: sound and electric power was fairly straightforward. Way too much transmission lines stuff in electric power lol. Light and matter was long but fair as well, didn't ask anything very 'out there' (although they don't seem to do that very often).
Post by: TrueTears on November 11, 2009, 03:44:26 pm
Yeah I drew a diagram.did anyone get 496nm for the wavelength?Yeah.
Did you bother drawing a diagram? They left such a massive space but it didn't really require that did it :S. Also it was only 2 marks.
My view of exam: sound and electric power was fairly straightforward. Way too much transmission lines stuff in electric power lol. Light and matter was long but fair as well, didn't ask anything very 'out there' (although they don't seem to do that very often).
Post by: tommyk221 on November 11, 2009, 03:45:18 pm
Electric power:
1. alternator
2. 8.0X10^(-3)T
3. 3.6X10^(-4)V
4. diagram
5. up
6. 0.0045N
7. 0 N
8.
9.1.00X10^4W
10. 4000W
11. 300V
12. 5000VRMS
13. 480 turns
14. 40.0W
15 498VRMS
16. T=0.040s, Vpeak=50V
Light and matter:
1. interference - wave property
2.
3. Thelma, same distance, constructive, bright
4. 496nm
5.
6. h=5.0X10^(-15)eVs, Work function=1.5V (no minus)
7. i) max k. e. not affected, ii) double
8. 8.9X10^3eV
9. 4.7X10^(-24)kgms-1
10.
11. first to second, first to third
12.Whole number of standing waves around nucleus.
Sound
BBCBCDCCBCAAA
Post by: chima987 on November 11, 2009, 03:48:50 pm
Post by: chima987 on November 11, 2009, 03:49:18 pm
Post by: TrueTears on November 11, 2009, 03:49:27 pm
what was question 5??Draw the arrow on the side of the motor or something.
Post by: homghomg1 on November 11, 2009, 03:50:14 pm
fuck, 1 mark question hopefully saying increase is enough :/
Post by: THem on November 11, 2009, 03:51:28 pm
what was q11 of light and matter?
Post by: homghomg1 on November 11, 2009, 03:52:45 pm
Haha I said increased as well.it was the one asking about which excited state the electrons in the atoms were initially in
what was q11 of light and matter?
Post by: sachinmachin on November 11, 2009, 03:53:06 pm
Post by: TrueTears on November 11, 2009, 03:53:28 pm
Post by: almostatrap on November 11, 2009, 03:53:35 pm
nvm just remembered
Post by: sachinmachin on November 11, 2009, 03:54:29 pm
Haha I said increased as well.it was the one asking about which excited state the electrons in the atoms were initially in
what was q11 of light and matter?
i put the initial excited state as the 3rd one. is this correct??
[/quote]
Post by: TrueTears on November 11, 2009, 03:54:56 pm
Nah it's the 1st one isn't it?Haha I said increased as well.it was the one asking about which excited state the electrons in the atoms were initially in
what was q11 of light and matter?
i put the initial excited state as the 3rd one. is this correct??
It absorbs, so it must be in a lower state.
Post by: NE2000 on November 11, 2009, 03:55:16 pm
Post by: NE2000 on November 11, 2009, 03:55:41 pm
Nah it's the 1st one isn't it?Haha I said increased as well.it was the one asking about which excited state the electrons in the atoms were initially in
what was q11 of light and matter?
i put the initial excited state as the 3rd one. is this correct??
It absorbs, so it must be in a lower state.
Yeah got 1st one
Post by: THem on November 11, 2009, 03:56:41 pm
What was Q4 (diagram ??? )
I think the magnetic field lines
Post by: sachinmachin on November 11, 2009, 03:56:57 pm
Nah it's the 1st one isn't it?Haha I said increased as well.it was the one asking about which excited state the electrons in the atoms were initially in
what was q11 of light and matter?
i put the initial excited state as the 3rd one. is this correct??
It absorbs, so it must be in a lower state.
FML EVEN MORE!!!
Post by: TrueTears on November 11, 2009, 03:57:23 pm
Post by: homghomg1 on November 11, 2009, 03:58:08 pm
What was Q4 (diagram ??? )
oops, i mean it was the one where you had to draw the magnetic field lines through electromagnet
Post by: IntoTheNewWorld on November 11, 2009, 03:58:21 pm
Post by: NE2000 on November 11, 2009, 04:00:00 pm
What was Q4 (diagram ??? )
I think the magnetic field lines
Oh yeah that's right :)
Post by: kashmuq on November 11, 2009, 04:00:12 pm
Post by: NE2000 on November 11, 2009, 04:00:27 pm
Post by: sachinmachin on November 11, 2009, 04:01:18 pm
Post by: homghomg1 on November 11, 2009, 04:01:31 pm
can someone link to itute answers pleasei don't think they're up yet,
i think that other guy who said he had itute solutions was trolling, or at least i couldn't find the solutions on itute myself
Post by: THem on November 11, 2009, 04:01:42 pm
theyre not even up on itute yet...
itute forums
Post by: kashmuq on November 11, 2009, 04:02:07 pm
Post by: THem on November 11, 2009, 04:02:53 pm
I mean the actual pdf file...can't find it on the website
Because it's not up
It's a post on the itute forums.
Post by: catweazle on November 11, 2009, 04:03:44 pm
the one how you had to draw four lines each with an arrow indicating the direction of the magnetic field. Where were the arrows suppose to go and in what direction
Post by: tommyk221 on November 11, 2009, 04:03:56 pm
iTute answers: (it's not the PDF yet)
http://www.itute.com/board/viewtopic.php?f=6&t=1251
Post by: NE2000 on November 11, 2009, 04:04:36 pm
what was answer to Q4 on electric power
the one how you had to draw four lines each with an arrow indicating the direction of the magnetic field. Where were the arrows suppose to go and in what direction
Lines up from the electromagnet and going around and back into it at the bottom?
Post by: TrueTears on November 11, 2009, 04:05:08 pm
Yeah.what was answer to Q4 on electric power
the one how you had to draw four lines each with an arrow indicating the direction of the magnetic field. Where were the arrows suppose to go and in what direction
Areas up from the electromagnet and going around and back into it at the bottom?
Post by: ayaz on November 11, 2009, 04:08:14 pm
Post by: catweazle on November 11, 2009, 04:09:23 pm
Given last years exams the grades were B+(132-147) A(148-161) A+(162-180)
Post by: /0 on November 11, 2009, 04:10:04 pm
Post by: NE2000 on November 11, 2009, 04:10:41 pm
how was the answer in light and matter Q4 496nm i got 331nm??
Difference in path difference between two dark fringes is equal to the wavelength
Post by: NE2000 on November 11, 2009, 04:11:14 pm
I did it like this
Did you use the big diagram space?
Post by: ayaz on November 11, 2009, 04:11:46 pm
do you think i could get a mark???
Post by: tommyk221 on November 11, 2009, 04:12:02 pm
how was the answer in light and matter Q4 496nm i got 331nm??
Path Difference to point A is 5/2 x wavelength
Path Difference to point B is 3/2 x wavelength
Therefore the difference between path differences is one wavelength
The question said the difference between path differences was 496nm
So the wavelength is 496nm.
Post by: homghomg1 on November 11, 2009, 04:13:06 pm
and then i said, in orbits where standing waves are not be formed, destructive interference will occur, and the electron will spiral towards the nucleus and that wave will cease to exist[/u]
i am sure destructive interference will occur, it says so on 2007 itute trial paper solutions, but not so sure about electrons spiralling in, shit, why did i write that. can anyome confirm whether this is garbage or if it makes sense?
for the path difference question i solved 2 simultaneous equations and got 496 nm (i think similar to what /0 did)
Post by: dylanru on November 11, 2009, 04:13:33 pm
exactly what I did :)how was the answer in light and matter Q4 496nm i got 331nm??
Path Difference to point A is 5/2 x wavelength
Path Difference to point B is 3/2 x wavelength
Therefore the difference between path differences is one wavelength
The question said the difference between path differences was 496nm
So the wavelength is 496nm.
Post by: poojon on November 11, 2009, 04:13:44 pm
Post by: TrueTears on November 11, 2009, 04:14:21 pm
I did it like thisExactly the same here.
Post by: kashmuq on November 11, 2009, 04:16:03 pm
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Post by: /0 on November 11, 2009, 04:16:20 pm
Did you use the big diagram space?
nah I didn't. 2 mark question bro
Post by: NE2000 on November 11, 2009, 04:19:07 pm
is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
Post by: NE2000 on November 11, 2009, 04:19:54 pm
for the de broglie question, i said only orbits which have a circumference which is a whole number multiple of the electron's de broglie wavelength can exist, blah blah blah blah
and then i said, in orbits where standing waves are not be formed, destructive interference will occur, and the electron will spiral towards the nucleus and that wave will cease to exist[/u]
i am sure destructive interference will occur, it says so on 2007 itute trial paper solutions, but not so sure about electrons spiralling in, shit, why did i write that. can anyome confirm whether this is garbage or if it makes sense?
for the path difference question i solved 2 simultaneous equations and got 496 nm (i think similar to what /0 did)
Not sure about the spiralling in thing. I think you might have got confused with the problem with the Bohr model and classical physics, which suggests that an electron orbit would be emitting EM radiation and hence would spiral into the nucleus...
Post by: tommyk221 on November 11, 2009, 04:21:13 pm
is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Try here for a blank paper:
http://vcenotes.com/forum/index.php/topic,19792.0.html
Post by: TrueTears on November 11, 2009, 04:21:21 pm
That one where you had to draw 4 lines?is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
I had the lines going in from the bottom out around the top and back in the bottom.
Post by: /0 on November 11, 2009, 04:22:34 pm
is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
Yeah it's probably ok. I guess VCE physics is like that... they don't tell you to draw inside bar magnets (and they don't tell you not to).
But really... every magnetic field is a closed loop.
Post by: TrueTears on November 11, 2009, 04:23:13 pm
Yeah so is it ok if I drew through the "bar magnet"? Cause I remember what you said... must be a closed loop.is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
Yeah it's probably ok. I guess VCE physics is like that... they don't tell you to draw inside bar magnets (and they don't tell you not to).
But really... every magnetic field is a closed loop.
Post by: homghomg1 on November 11, 2009, 04:23:17 pm
is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
yeah, it said in the region around the iron core
i don't think the iron core is necessarily a permanent magnet anyway, it just helps to channel the magnetic field by increasing its strength (cos it's a temporary magnet when subject to the field of the wires? not sure on this)
anyway, i think you just had to draw the 4 lines going from bottom to top, and show them coming back to the bottom on the outside of the wires as well if you wanted to be sure
Post by: ayaz on November 11, 2009, 04:25:13 pm
Post by: homghomg1 on November 11, 2009, 04:27:06 pm
for the de broglie question, i said only orbits which have a circumference which is a whole number multiple of the electron's de broglie wavelength can exist, blah blah blah blah
and then i said, in orbits where standing waves are not be formed, destructive interference will occur, and the electron will spiral towards the nucleus and that wave will cease to exist[/u]
i am sure destructive interference will occur, it says so on 2007 itute trial paper solutions, but not so sure about electrons spiralling in, shit, why did i write that. can anyome confirm whether this is garbage or if it makes sense?
for the path difference question i solved 2 simultaneous equations and got 496 nm (i think similar to what /0 did)
Not sure about the spiralling in thing. I think you might have got confused with the problem with the Bohr model and classical physics, which suggests that an electron orbit would be emitting EM radiation and hence would spiral into the nucleus...
"energy levels of the atom could not be explained in terms of the Newtonian model , since orbiting objects are by definition accelerating and should therefore be gradually losing energy, and thus should be expected to spiral in towards the nucleus eventually crashing into it. But this was not in accord with the observed facts. What therefore was it that kept the electrons within their discrete ‘scale-like’ positions at particular distances from the nucleus"
this is from some website. hmm I don't know, it does say that they are expected to spiral in towards the nucleus according to the newtonian model, and the reason they don't (as De Broglie discovered) is due to the presence of standing waves. Ughh.. I hope they don't mark me down :/
Post by: TrueTears on November 11, 2009, 04:27:42 pm
for the iron core Q i drew the lines inside the iron would i get full marks???I don't know, I remember /0 saying every magnetic field must be a closed loop so I drew them through the iron.
Post by: NE2000 on November 11, 2009, 04:28:58 pm
is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
Yeah it's probably ok. I guess VCE physics is like that... they don't tell you to draw inside bar magnets (and they don't tell you not to).
But really... every magnetic field is a closed loop.
If it were a bar magnet you wouldn't lose any marks for not going through it. If it were a solenoid you would have to go through it. So the issue is that because it is an electromagnet, is there extra significance to the fact that the field lines travel through the core? Is there any significant difference between the actual magnetic properties of an electromagnet and a bar magnet?
Post by: /0 on November 11, 2009, 04:29:11 pm
That one where you had to draw 4 lines?is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
I had the lines going in from the bottom out around the top and back in the bottom.
Yeah that's kinda what I did with the outer two lines, but with the inner two I didn't loop them, I just let them go off the page
All my lines went through the bar magnet
Post by: TrueTears on November 11, 2009, 04:29:40 pm
I think they're exactly the same just that an electromagnet is not permanent and lose its magnetism as soon as the current is turned off. Thus it acts just like a bar magnet as long as there is current.is anyone posting up a blank exam copy? :D
also with the magnet (q4), was it ok to draw lines going from top to bottom (i.e. like a normal bar magnet) without going through the bar?
Yeah that's what I did. An electromagnet behaves like a permanent magnet... Anyone else (TT, /0 ?)
Yeah it's probably ok. I guess VCE physics is like that... they don't tell you to draw inside bar magnets (and they don't tell you not to).
But really... every magnetic field is a closed loop.
If it were a bar magnet you wouldn't lose any marks for not going through it. If it were a solenoid you would have to go through it. So the issue is that because it is an electromagnet, is there extra significance to the fact that the field lines travel through the core? Is there any significant difference between the actual magnetic properties of an electromagnet and a bar magnet?
Post by: homghomg1 on November 11, 2009, 04:29:53 pm
Post by: NE2000 on November 11, 2009, 04:32:55 pm
lol I think the iron bar occupies pretty much the whole space inside the wires, so it'd be hard to draw the lines not going through it
No I think you are misinterpreting what I'm saying. I had my field lines starting at the north end and looping around going to the south pole. I didn't draw them going through the iron core.
Post by: almostatrap on November 11, 2009, 04:34:10 pm
Post by: NE2000 on November 11, 2009, 04:35:11 pm
with the iron bar, i think everyone will get fulls marks either way. you cant lose marks for adding in detail
can you lose marks for not adding in detail though ...
Post by: homghomg1 on November 11, 2009, 04:35:16 pm
ohh i seelol I think the iron bar occupies pretty much the whole space inside the wires, so it'd be hard to draw the lines not going through it
No I think you are misinterpreting what I'm saying. I had my field lines starting at the north end and looping around going to the south pole. I didn't draw them going through the iron core.
hmm i don't know, i just did it as a normal electromagnet (through the bar)
Post by: avram_grant on November 11, 2009, 04:37:18 pm
Post by: almostatrap on November 11, 2009, 04:38:50 pm
Post by: Fireworks on November 11, 2009, 04:41:33 pm
Post by: ayaz on November 11, 2009, 04:42:08 pm
Post by: avram_grant on November 11, 2009, 04:42:46 pm
Post by: catweazle on November 11, 2009, 04:44:03 pm
Given last years exams the grades were B+(132-147) A(148-161) A+(162-180)
Post by: avram_grant on November 11, 2009, 04:44:41 pm
Ok, i've marked my exam. What grade do you guys/girls think i will get for a 153/180
Given last years exams the grades were B+(132-147) A(148-161) A+(162-180)
A i think
Post by: ayaz on November 11, 2009, 04:45:01 pm
Post by: avram_grant on November 11, 2009, 04:45:51 pm
is th 78-80/90 for an A+?? or an A
A+
Post by: ayaz on November 11, 2009, 04:56:02 pm
would this be correct???
Post by: homghomg1 on November 11, 2009, 04:59:03 pm
Ok, i've marked my exam. What grade do you guys/girls think i will get for a 153/180
Given last years exams the grades were B+(132-147) A(148-161) A+(162-180)
I think you will get a mid to high A
I personally think the difficulty of this exam was higher than last year
if you look at the 08 examiner's report, you will see most marks are lost in explanation questions
Electric power Q10) question regarding application of lenz's law requiring an explanation, only 13% got 4 out of 4
Light Q1) simple question about how light globes produce light, only 22% got 2 out of 2
Light Q2) asks how light from globes differ from mercury lamps, only 41% got 2 out of 2
Light Q4) double slit question, asking why a bright band is formed in a certain spot on the screen, only 20% got 2 out of 2
There were some considerably harder explanation questions this year (a lot of people will lose marks on the two questions asking how young's experiment and the photoelectric effect support each model of light), so I'm thinking the A+ mark will be a little lower. Even if people say the owned the exam, that's the problem with explanation questions, you really don't know and you often don't do as well as you expect.
Post by: Over9000 on November 11, 2009, 05:04:56 pm
Post by: TrueTears on November 11, 2009, 05:06:15 pm
Post by: homghomg1 on November 11, 2009, 05:06:59 pm
hey for the question it says determine the work fn and h i used the threshold freq (3E14)and then determined the h and W..
would this be correct???
well the formula is W = hf0
so you can't work out both just by using that formula after reading the value of f0, you'd have to use the graph in some other way also
I think you could work out the h for that experiment by evaluating the gradient of the graph, then, using the h you worked out, you could find W using W = hf0
But I would still prefer to just find W by reading the y-intercept
I guess you could also do it the other way around. Find W by reading y-intercept, then work out h using the formula h = W/f0
Post by: angelboykevin on November 11, 2009, 05:07:10 pm
Post by: poojon on November 11, 2009, 05:07:21 pm
90/90 in midyear exam
86-90/90 on end of year depending on explain questions
94/100 unit 3 SACs
91/100 unit 4 SACs
ranked about 3-5th on SACs out of 3 classes of about 20 students each
Post by: ayaz on November 11, 2009, 05:07:37 pm
Post by: THem on November 11, 2009, 05:07:47 pm
Post by: NE2000 on November 11, 2009, 05:09:02 pm
u guys think i will lose mark for writing too much?
you're kidding right?
Post by: angelboykevin on November 11, 2009, 05:11:00 pm
of course not, why would i ,,,lol what do u think abt it?u guys think i will lose mark for writing too much?
you're kidding right?
Post by: /0 on November 11, 2009, 05:12:41 pm
Post by: TrueTears on November 11, 2009, 05:13:32 pm
lol i will shit myself if i ace this exam, I have never aced an end of year examYou aced it for sure. Just like how you ace every single SACs you pr0 kent.
Post by: crappy on November 11, 2009, 05:14:42 pm
of course not, why would i ,,,lol what do u think abt it?u guys think i will lose mark for writing too much?
you're kidding right?
actually you could, because all the extra things you said could contradict you main explanation hence you will get marks taken off. Im guessing.
Post by: appianway on November 11, 2009, 05:15:45 pm
what kind of study score would i get for physics?
90/90 in midyear exam
86-90/90 on end of year depending on explain questions
94/100 unit 3 SACs
91/100 unit 4 SACs
ranked about 3-5th on SACs out of 3 classes of about 20 students each
It depends on the strength of your cohort. Maybe 47+?
Post by: /0 on November 11, 2009, 05:16:07 pm
lol i will shit myself if i ace this exam, I have never aced an end of year examYou aced it for sure. Just like how you ace every single SACs you pr0 kent.
yeah well you will ace it for sure, just like how you ace (pretty much) every single EXAM :p
Post by: almostatrap on November 11, 2009, 05:34:50 pm
exam 1: 88/90
exam 2: 89/90
top ranked for sacs
Post by: avram_grant on November 11, 2009, 05:38:07 pm
what kind of study score would this be?
exam 1: 88/90
exam 2: 89/90
top ranked for sacs
lol, 49 or 50
Post by: almostatrap on November 11, 2009, 05:40:30 pm
Post by: NE2000 on November 11, 2009, 05:41:31 pm
Post by: appianway on November 11, 2009, 05:41:50 pm
Post by: TrueTears on November 11, 2009, 05:43:04 pm
I don't think more than 15 or so students are going to get a perfect score on this exam (because, despite what people are saying, I think a lot of people will drop unexpected marks for the explanations) - it was considerably more demanding than previous exams. And out of this 15, I don't think all would've scored 100% on exam 1 and SACs.I totally agree here.
Post by: scope9 on November 11, 2009, 05:44:00 pm
Post by: NE2000 on November 11, 2009, 05:46:01 pm
I don't think more than 15 or so students are going to get a perfect score on this exam (because, despite what people are saying, I think a lot of people will drop unexpected marks for the explanations) - it was considerably more demanding than previous exams. And out of this 15, I don't think all would've scored 100% on exam 1 and SACs.
Out of my experiences with my 3/4 last year (and that of people I know who got their statement of marks), it appears that in a subject where one exam is disproportionately more difficult/tricky than the other, the more difficult one has a far greater impact on your study score. Which is why I told people who lost a couple of marks on physics midyear that rebounding is very possible.
Post by: appianway on November 11, 2009, 05:50:08 pm
Post by: Kermit on November 11, 2009, 05:55:52 pm
90/90 1st exam
87/90 2nd exam
and top 3 for SACs at my school (relatively high achieving).
Post by: avram_grant on November 11, 2009, 06:33:32 pm
Post by: crappy on November 11, 2009, 06:35:59 pm
89/90 exam 1
86/90 exam 2
With second ranking in a good cohort. gah, I messed up physics big time.
Post by: avram_grant on November 11, 2009, 06:39:22 pm
what about:
89/90 exam 1
86/90 exam 2
With second ranking in a good cohort. gah, I messed up physics big time.
i dont think youve messed up, thats mid-high 40s raw
Post by: crappy on November 11, 2009, 06:40:13 pm
what about:
89/90 exam 1
86/90 exam 2
With second ranking in a good cohort. gah, I messed up physics big time.
i dont think youve messed up, thats mid-high 40s raw
thanks mate, that really means alot to me right now. I would karma you but I dont have enough posts.
Post by: scope9 on November 11, 2009, 06:40:42 pm
Post by: TrueTears on November 11, 2009, 06:41:39 pm
Yeah that is an awesome score, easily in the 40's.what about:
89/90 exam 1
86/90 exam 2
With second ranking in a good cohort. gah, I messed up physics big time.
i dont think youve messed up, thats mid-high 40s raw
thanks mate, that really means alot to me right now. I would karma you but I dont have enough posts.
Post by: crappy on November 11, 2009, 06:43:40 pm
Yeah that is an awesome score, easily in the 40's.what about:
89/90 exam 1
86/90 exam 2
With second ranking in a good cohort. gah, I messed up physics big time.
i dont think youve messed up, thats mid-high 40s raw
thanks mate, that really means alot to me right now. I would karma you but I dont have enough posts.
lol thanks TT, champion!
Post by: BlueYoHo on November 11, 2009, 06:45:41 pm
Exam 1: 87/90 (only person to get an A+)
Exam 2: 85/90 (worst case scenario)
Sacs: High A (89%) and ranked maybe top 7 out of some 50 kids... (isn't too good lol)
Post by: BlueYoHo on November 11, 2009, 06:46:49 pm
Post by: scope9 on November 11, 2009, 06:54:42 pm
a kid doing chem last year did really well within his class. top exams & sacs but still only got a raw of 34 because nobody else in his class got above a d?
Post by: avram_grant on November 11, 2009, 06:57:48 pm
how much does the exam score matter? dont they change your sac marks and exam scores so that everything is ranked according to your class within your school within the rest of victoria? thats what our teachers say anyway.
a kid doing chem last year did really well within his class. top exams & sacs but still only got a raw of 34 because nobody else in his class got above a d?
Its the other way around, if you ace exams, sacs dont really mean much
Post by: BlueYoHo on November 11, 2009, 06:59:53 pm
Its the other way around, if you ace exams, sacs dont really mean muchsweet, i hope so :)
nothing i can do now anyway, just gotta sit back and wait..
Post by: scope9 on November 11, 2009, 07:00:26 pm
Post by: methodsboy on November 11, 2009, 07:10:27 pm
i drew four lines just outside the wire..i was tempted to draw inside it but refused...is that still correct?lol I think the iron bar occupies pretty much the whole space inside the wires, so it'd be hard to draw the lines not going through it
No I think you are misinterpreting what I'm saying. I had my field lines starting at the north end and looping around going to the south pole. I didn't draw them going through the iron core.
Post by: ngRISING on November 11, 2009, 07:17:12 pm
Post by: TrueTears on November 11, 2009, 07:23:16 pm
i reckon this exam was too easy, i finished 1hour and 20minutes early.LOL hahahahaha
Post by: scope9 on November 11, 2009, 07:25:32 pm
i reckon this exam was too easy, i finished 1hour and 20minutes early.
for a second i was like WTF?! but then i realised that you only did detailed study. hahaha
Post by: THem on November 11, 2009, 07:55:03 pm
what would you need to get high 30 raw?
I'd like to know this as well ;)
Post by: dcc on November 11, 2009, 07:56:53 pm
for the iron core Q i drew the lines inside the iron would i get full marks???I don't know, I remember /0 saying every magnetic field must be a closed loop so I drew them through the iron.
Mathematically, you can express that statement as
However, not all field lines must form a closed loop, as the above statement is more of a simplifying definition (at least, as far as I know) rather then the grand truth. Read: magnetic monopoles.
Post by: /0 on November 11, 2009, 08:03:36 pm
Post by: dcc on November 11, 2009, 08:06:43 pm
He has.
Post by: scope9 on November 11, 2009, 08:13:18 pm
http://en.wikipedia.org/wiki/Blas_Cabrera
He has.
dark matter?
golden compas anyone :P
Post by: Apeman007 on November 11, 2009, 08:18:44 pm
would that be one mark off...
Post by: Apeman007 on November 11, 2009, 08:29:34 pm
Post by: avram_grant on November 11, 2009, 08:31:04 pm
Post by: poppa on November 11, 2009, 08:48:52 pm
just curious what raw will i get?
Post by: appianway on November 11, 2009, 08:49:19 pm
Post by: THem on November 11, 2009, 08:50:17 pm
Hey everyone i got a mid-high A for mid yr, maybe a A+ for end of yr, and A for sacs
just curious what raw will i get?
high 30's, maybe low 40's depending on whether that A+ is a low/med/high and how good your physics cohort performs in comparison to other schools.
Post by: scope9 on November 11, 2009, 09:08:40 pm
Post by: Spluff on November 11, 2009, 10:26:20 pm
Post by: Over9000 on November 11, 2009, 10:28:05 pm
For question 1. in the Light & Matter, would we have to refer to both interference AND diffraction to get full marks? I only referred to diffraction.Shit, I only did interference I think, gg??
Post by: methodsboy on November 11, 2009, 10:32:08 pm
i did both.. after discovering that i was rambling about the photoelectric effect and crossing about 4/6 lines for that question.... stupid VCAA didnt even put blank pages this year on the page!!
grrr
Post by: TrueTears on November 11, 2009, 10:34:14 pm
For question 1. in the Light & Matter, would we have to refer to both interference AND diffraction to get full marks? I only referred to diffraction.I did both.
Post by: Over9000 on November 11, 2009, 10:35:53 pm
Post by: Spluff on November 11, 2009, 10:43:05 pm
Post by: scope9 on November 11, 2009, 11:24:37 pm
Post by: vietsmista on November 12, 2009, 12:03:26 am
Post by: /0 on November 12, 2009, 07:52:28 am
I thought it was risky drawing loops cuz technically they did say "lines"
Post by: ngRISING on November 12, 2009, 12:15:38 pm
Post by: NE2000 on November 12, 2009, 02:25:16 pm
Ah crap is this ok?
I thought it was risky drawing loops cuz technically they did say "lines"
That should be ok. I'm worried about
Post by: scope9 on November 12, 2009, 02:51:37 pm
Ah crap is this ok?
I thought it was risky drawing loops cuz technically they did say "lines"
itute says loops so i suppose loops will be fine!
whats diffraction?
did you even do physics? haha. just kidding
its the bending of light as it passes through a gap. the amount of diffraction depends on the wavelength:gap ratio. or something like that.
Post by: metalvalour on November 12, 2009, 03:06:47 pm
Ah crap is this ok?
I thought it was risky drawing loops cuz technically they did say "lines"
did exactly what you did. but itute's one doesnt have the 2 lines (not loops)?! :(
Post by: wilfred on November 12, 2009, 04:54:31 pm
question 2
Which one of the following statements best describe the production of light in an incandescent light bulb?
I know its between
C.Acceleration of electron in random thermal collisions
D. Emission of electromagnetic radiation (light) by electrons accelerated by the applied voltage
which one is it? and why is it not the other one?
thanks heaps
Post by: mark_alec on November 12, 2009, 05:22:00 pm
For D, that would be an example of synchrotron light, as it is caused by the acceleration of electrons in an electric field.
Post by: majo on November 12, 2009, 11:59:13 pm
TrueTears id like to sincerely thankyou for providing us with that cheat sheet. Im pretty sure it has gotten me an A-A+, i cant find any errors. Does anyone know what a B+ and a high A would get me in terms of SS?
i am also curious
high B and a A+/high A
?
Post by: ayaz on November 13, 2009, 04:08:53 pm
I used W = hf "zero"
But instead of using the value of h calculated from the graph I used the accepted value (4.14x10^-15) and ended up with something like 1.3 eV
Do you guys think i'd lose the marks, seeing as it asks you to use the graph? is using f "zero" from the graph enough?
i did what was above but on the working space i also used the graph and estimated that the W is 1.5ev and used this to determine h and i put the answer to h and W NOT inside the BOX where you put the answer in but ON the TOP of the BOX and inside the box i did what redmosez did and put h=4.14E.14evs in the box and 1.3ev in the box....
do you think i could get the marks (3marks)
Post by: crappy on November 14, 2009, 02:06:19 pm
So I think I might have stuffed up the question on the exam that asks you to calculate W.
I used W = hf "zero"
But instead of using the value of h calculated from the graph I used the accepted value (4.14x10^-15) and ended up with something like 1.3 eV
Do you guys think i'd lose the marks, seeing as it asks you to use the graph? is using f "zero" from the graph enough?
i did what was above but on the working space i also used the graph and estimated that the W is 1.5ev and used this to determine h and i put the answer to h and W NOT inside the BOX where you put the answer in but ON the TOP of the BOX and inside the box i did what redmosez did and put h=4.14E.14evs in the box and 1.3ev in the box....
do you think i could get the marks (3marks)
you might get the marks, If its asking for the work function then all you had to was read off the graph( the y intercept). I cant really remember but, you didn't really need to work out anything for that question, besides reading the graph.
Post by: methodsboy on November 16, 2009, 10:22:09 pm
So I think I might have stuffed up the question on the exam that asks you to calculate W.OMG dude get over it! it happened all most a week ago... cease with the futile lamenting
I used W = hf "zero"
But instead of using the value of h calculated from the graph I used the accepted value (4.14x10^-15) and ended up with something like 1.3 eV
Do you guys think i'd lose the marks, seeing as it asks you to use the graph? is using f "zero" from the graph enough?
i did what was above but on the working space i also used the graph and estimated that the W is 1.5ev and used this to determine h and i put the answer to h and W NOT inside the BOX where you put the answer in but ON the TOP of the BOX and inside the box i did what redmosez did and put h=4.14E.14evs in the box and 1.3ev in the box....
do you think i could get the marks (3marks)