Post by: MaNi_DaDuDe on October 30, 2009, 06:33:13 pm
Any help would be appreciates. :)
Post by: pravin_5 on October 31, 2009, 01:36:43 am
Post by: heemvi on October 31, 2009, 04:08:31 am
cn u plzzz hlp me!!
Post by: MaNi_DaDuDe on October 31, 2009, 01:59:42 pm
hang on mani.....i'll try to find smth!! are u doing paper 33??? mine is paper 33 on 3rd nov.... ;D
Hey Pravin. :)
Yes I am doing paper 33 and on the 3rd of November.
Any help of any sort would be awesome.
Post by: pravin_5 on November 01, 2009, 02:51:02 pm
am doing ppr 32...on tuesDsoooo sorry heemvi,,, bt all d students in my school are doing paper 33 for oct/nov 09...
cn u plzzz hlp me!!
sorry......bt knw what instead of looking for predictions...i strongly encourage you to revise ur past papers...learn hw to tabulate data accurately....well u mite know that raw data depends on dp of the measurement while processed data depends on sf of the raw data.....for clarification look at marking scheme...then uncertainty in measurements, hw to justify the given statement( explain whether x is proportional to y), drawing graph and ect....and and sources of error and method of improvement for both electrical or mechanical type of questions.....(1 popular answer is that two readings are not enough to draw a valid conclusion.....to improve....repeat the experiment several times to obtain 6 sets of reading and plot a graph)
all the best wishes from me
Post by: raunaqbhatia on November 01, 2009, 02:55:27 pm
Post by: MaNi_DaDuDe on November 01, 2009, 06:25:35 pm
soooo sorry heemvi,,, bt all d students in my school are doing paper 33 for oct/nov 09...
sorry......bt knw what instead of looking for predictions...i strongly encourage you to revise ur past papers...learn hw to tabulate data accurately....well u mite know that raw data depends on dp of the measurement while processed data depends on sf of the raw data.....for clarification look at marking scheme...then uncertainty in measurements, hw to justify the given statement( explain whether x is proportional to y), drawing graph and ect....and and sources of error and method of improvement for both electrical or mechanical type of questions.....(1 popular answer is that two readings are not enough to draw a valid conclusion.....to improve....repeat the experiment several times to obtain 6 sets of reading and plot a graph)
all the best wishes from me
Thanks!
+rep'd :)
Post by: falafail on November 01, 2009, 07:57:55 pm
well u mite know that raw data depends on dp of the measurement while processed data depends on sf of the raw data.....
could someone explain this please? :/
Post by: lalib10 on November 01, 2009, 08:19:09 pm
Question number 1d
Taking the values of
I=43.4x10^-3
R3=47
y-intercept as = 7
Post by: falafail on November 01, 2009, 08:29:22 pm
Can sum1 plx explain me how to do the question of may/june 2007 P32
Question number 1d
Taking the values of
I=43.4x10^-3
R3=47
y-intercept as = 7
okay, you know that the equation of a straight line is y=mx+c right?
in this case, 1/I is y, R3 is x, (R1+R2/ER2) is m (the gradient) and R1/E is c (the y-intercept)
geddit?
just, next time you have a questino like this (which we will, almost definitely), write y=mx+c above the equation given and see which values match with which.
in this question, substitute the values you got for the gradient and the y-intercept to find R1 and R2.
Post by: astarmathsandphysics on November 01, 2009, 08:35:36 pm
Can sum1 plx explain me how to do the question of may/june 2007 P32
Question number 1d
Taking the values of
I=43.4x10^-3
R3=47
y-intercept as = 7
You measured the emf of the power supply at the start of this question. Suppose it is 240V
y intercept is R1/E=7 so R1/240=7 so R1=240*7=1680
You find the gradient from the graph. Suppose you found it was 2
Post by: lalib10 on November 01, 2009, 09:32:13 pm
astarmathsandphysics and falafail
Post by: lalib10 on November 01, 2009, 09:38:23 pm
like for diameter of wire it is 0.01
can you tell me a site or give me a list of most of the uncertainties....
thnxx
Post by: astarmathsandphysics on November 01, 2009, 10:58:57 pm
In general the unvertainy is equal to the smallest interval on the scale.
Post by: MaNi_DaDuDe on November 02, 2009, 05:03:07 am
I will try and make a page for my website but wont be able to do it until tomorrow.
In general the unvertainy is equal to the smallest interval on the scale.
Exam's tomorrow.
Post by: heemvi on November 02, 2009, 07:29:03 am
wel i tried 2 chk mny pprs n thr mark sheme...
n it did hlp a lot
nly 1 question.
can sm1 hlp me abt the numbr of significant fig of a calculatd data where log hs bin used???
its quite cnfusin.(am referin 2 both practical n data analysis)
Post by: raunaqbhatia on November 02, 2009, 07:41:54 am
Post by: astarmathsandphysics on November 02, 2009, 08:38:51 am
Post by: falafail on November 02, 2009, 09:52:11 am
I will try and make a page for my website but wont be able to do it until tomorrow.
In general the unvertainy is equal to the smallest interval on the scale.
.. i thought it was half of the smallest interval?
Post by: Sorceres on November 02, 2009, 09:55:03 am
Thanks u vry much pravin_5 for the advices..
wel i tried 2 chk mny pprs n thr mark sheme...
n it did hlp a lot
nly 1 question.
can sm1 hlp me abt the numbr of significant fig of a calculatd data where log hs bin used???
its quite cnfusin.(am referin 2 both practical n data analysis)
for calculated data its normally 3sf. in general for calculated data, u use the sig fig of the raw data..
Post by: Sorceres on November 02, 2009, 09:56:49 am
.. i thought it was half of the smallest interval?
its half the smallest interval but then for example in metre rule, u have to add both uncertainties together, the one at d beginning and the end.. so 0.05cm+0.05cm= 0.1cm
Post by: MaNi_DaDuDe on November 02, 2009, 10:50:38 am
How do you measure an angle with a (HUGE) protactor better?
Help please, thanks.
Post by: raunaqbhatia on November 02, 2009, 11:44:19 am
Post by: falafail on November 02, 2009, 11:46:52 am
How do you measure an angle with a (HUGE) protactor better?
hmm, you could check your measurement with a smaller protractor?
Post by: MaNi_DaDuDe on November 02, 2009, 12:08:04 pm
hmm, you could check your measurement with a smaller protractor?
DUDE, the apparatus is huge. :(
We need a big protactor to measure the angle.
Post by: falafail on November 02, 2009, 12:10:05 pm
DUDE, the apparatus is huge. :(
We need a big protactor to measure the angle.
yeah, i know. i saw it.
i measured the angle using my protractor though, and the teacher said it's okay as long as you write that you CHECKED the angle with a small protractor XD
Post by: MaNi_DaDuDe on November 02, 2009, 12:18:37 pm
yeah, i know. i saw it.
i measured the angle using my protractor though, and the teacher said it's okay as long as you write that you CHECKED the angle with a small protractor XD
Whoa, how the f*** ?
You put the middle of your little protactor on the middle of the string and did what..? :S
Post by: falafail on November 02, 2009, 12:21:14 pm
Whoa, how the f*** ?
You put the middle of your little protactor on the middle of the string and did what..? :S
you align it with the horizontal string, and just measure the angle it makes with the other one. :-\
Post by: MaNi_DaDuDe on November 02, 2009, 12:29:16 pm
you align it with the horizontal string, and just measure the angle it makes with the other one. :-\
That's for the newton meter one, yeah?
By the way, the other exp. 08 one, we have to measure the angle and then do 180 - the angle right?
Post by: falafail on November 02, 2009, 12:37:26 pm
That's for the newton meter one, yeah?
By the way, the other exp. 08 one, we have to measure the angle and then do 180 - the angle right?
ah, i don't know. i haven't seen it.
post the question?
Post by: MaNi_DaDuDe on November 02, 2009, 12:40:25 pm
http://www.xtremepapers.net/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_s08_qp_31.pdf (http://www.xtremepapers.net/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_s08_qp_31.pdf)
Post by: falafail on November 02, 2009, 12:43:08 pm
I think it was this one,
http://www.xtremepapers.net/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_s08_qp_31.pdf (http://www.xtremepapers.net/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_s08_qp_31.pdf)
why would you do 180 minus the angle? just measure it.. :-\
Post by: MaNi_DaDuDe on November 02, 2009, 12:48:37 pm
why would you do 180 minus the angle? just measure it.. :-\
That's if you read it from the left, you do 180 - angle.. right?
Else just measure whole angle from right.
???
Post by: falafail on November 02, 2009, 01:04:21 pm
That's if you read it from the left, you do 180 - angle.. right?
Else just measure whole angle from right.
???
i have no idea what you're saying tbh.
your protractor measures both ways.. so.. just measure from the side you aligned the string with? :-\
Post by: khi2ruh on November 02, 2009, 03:09:57 pm
usually for graphs i don't usually know how t set my scale up.
like this question on may/june 2008 31,my values for cos(Q/2) were from 0.79 to 0.87,six of them and they had to be plotted on the y axis.if i start from 0 and go on like 0.1,0.2,0.3... then its like i have wasted half my space and then my graph is right at the top,the examiners want us to use 3/4 of the spce available,so im not sure if im right or not.
Post by: Sorceres on November 02, 2009, 03:13:17 pm
hey desperate help required!
usually for graphs i don't usually know how t set my scale up.
like this question on may/june 2008 31,my values for cos(Q/2) were from 0.79 to 0.87,six of them and they had to be plotted on the y axis.if i start from 0 and go on like 0.1,0.2,0.3... then its like i have wasted half my space and then my graph is right at the top,the examiners want us to use 3/4 of the spce available,so im not sure if im right or not.
u don't have to start from zero.
Post by: khi2ruh on November 02, 2009, 03:28:54 pm
u don't have to start from zero.
oh i knew u could do that for x axis but can u do that for y-axis aswell?
and then if not zero then how do u do it i mean..leave the first block and then start with wateva value or just start from the value directly?
Post by: falafail on November 02, 2009, 03:34:24 pm
oh i knew u could do that for x axis but can u do that for y-axis aswell?
and then if not zero then how do u do it i mean..leave the first block and then start with wateva value or just start from the value directly?
"If either axis does not start from zero, this should be emphasised. A small zig-zag can be
inserted in the axis between the origin and the first scale point. Any other breaks in the axis
should be similarly marked."
Post by: Sorceres on November 02, 2009, 03:39:12 pm
oh i knew u could do that for x axis but can u do that for y-axis aswell?
and then if not zero then how do u do it i mean..leave the first block and then start with wateva value or just start from the value directly?
what i do is for the supposed "origin" horizontal line.. i write the value..
Post by: khi2ruh on November 02, 2009, 03:46:55 pm
for the percentage uncertainty in Q(angle) will it be like
0.5/value of Q *100?
Post by: Sorceres on November 02, 2009, 03:52:58 pm
thanks ppl, i was totally confused on that matter,now i get it.
for the percentage uncertainty in Q(angle) will it be like
0.5/value of Q *100?
uncertainty for angle is 1
Post by: falafail on November 02, 2009, 03:53:37 pm
thanks ppl, i was totally confused on that matter,now i get it.
for the percentage uncertainty in Q(angle) will it be like
0.5/value of Q *100?
i think it's 1/value of Q * 100.
Post by: Asif iqbal on November 02, 2009, 04:38:28 pm
Post by: Asif iqbal on November 02, 2009, 04:45:36 pm
Post by: falafail on November 02, 2009, 05:21:58 pm
in one of the past papers, a ruler was suspended from strings, and one of the questions was to explain how you ensured that the ruler was horizontal.
i checked the examiner report, this is what it said:
"Most candidates stated that they would measure the distance of the rule from the bench top at
each end of the rule, and that the values would be the same if the rule was horizontal. This was
accepted for one mark. The more able candidates went on to give further detail, usually involving
the set square, to gain a second mark."
could someone explain what that last part means? the set square? ???
Post by: slammer951 on November 02, 2009, 05:28:43 pm
Post by: khi2ruh on November 02, 2009, 06:30:33 pm
..column heading
Post by: falafail on November 02, 2009, 06:43:23 pm
are there any units for cos(Q/2)?
..column heading
no, but in one mark scheme they'd written it as "cos(Q/2(°))" so there was a unit for the Q/2 part, but not for the actual column.
Post by: MaNi_DaDuDe on November 02, 2009, 06:50:55 pm
Ummm can u ppl plz find a list Of errors limitations and Dere solutions....
I need the very same info.
Errors, accuracies about protectors and stuff other than parallax error
Post by: falafail on November 02, 2009, 06:53:24 pm
I need the very same info.
Errors, accuracies about protectors and stuff other than parallax error
lol, protectors :P
dude, just go over the ones in previous past papers. i just did, and i came to one conclusion: examiners are *censored* schizophrenic.
sometimes they say you get marks for something, and others it's like "no credit given".... yep, schizos. >:[
Post by: MaNi_DaDuDe on November 02, 2009, 06:55:23 pm
Dude I still want like main errors possible with protactors and stuff cuz like all I know is we need to clamp it foe better results as it is in air or some sh*t. Help :(
Post by: falafail on November 02, 2009, 06:59:04 pm
rofl its my phone's autocorrect. (iPhone bleh)
Dude I still want like main errors possible with protactors and stuff cuz like all I know is we need to clamp it foe better results as it is in air or some sh*t. Help :(
ah yeah, out of all the past papers only one error/improvement thingie was about protractors. the one with the bottle and measuring the angle? it's similar to the one we had in may/june.
but yeah, it only said that you can use a clamp to hold the protractor still (you get no credit for saying "a clamp to hold the BOTTLE" though) because it's hard to keep it steady while holding the bottle as well.
other than that, i'm just as clueless as you are :'(
Post by: MaNi_DaDuDe on November 02, 2009, 07:01:37 pm
ah yeah, out of all the past papers only one error/improvement thingie was about protractors. the one with the bottle and measuring the angle? it's similar to the one we had in may/june.
but yeah, it only said that you can use a clamp to hold the protractor still (you get no credit for saying "a clamp to hold the BOTTLE" though) because it's hard to keep it steady while holding the bottle as well.
other than that, i'm just as clueless as you are :'(
Then I guess we are in the same boat.
I got that clamp thing from mj09
Post by: falafail on November 02, 2009, 07:03:46 pm
Then I guess we are in the same boat.
I got that clamp thing from mj09
yeah, the one with the bottle, right?
i don't think we're gonna get something like that again though..
Post by: MaNi_DaDuDe on November 02, 2009, 07:22:02 pm
yeah, the one with the bottle, right?
i don't think we're gonna get something like that again though..
Yeah same one.
Nah bottle can't come again.
Post by: falafail on November 02, 2009, 07:26:18 pm
Yeah same one.
Nah bottle can't come again.
good, it was messy XD
Post by: raunaqbhatia on November 02, 2009, 07:48:43 pm
Post by: falafail on November 02, 2009, 07:50:50 pm
true
great input man :P
Post by: MaNi_DaDuDe on November 02, 2009, 08:16:17 pm
Someone please state them.
Post by: MaNi_DaDuDe on November 02, 2009, 09:36:10 pm
Andd in tabulating data, what format is preferred? (experiments in rows?$
Post by: astarmathsandphysics on November 02, 2009, 09:51:19 pm
Post by: falafail on November 03, 2009, 03:24:55 am
What are the formulas to be learnt?
Someone please state them.
we don't have any formulas to learn? :-\
sometimes we just have to know basic ones like F=ma and W=mg etc
Post by: falafail on November 03, 2009, 08:18:36 am
For me, the first one was really good; the second... Not so much. It wasn't terrible though. :)
Post by: NzJames on November 03, 2009, 09:13:16 am
Post by: MaNi_DaDuDe on November 03, 2009, 11:16:20 am
I hope I do well, but I can't say I did good nor can I say I did VERY bad.
Post by: Sorceres on November 03, 2009, 12:26:02 pm
f**k the values of v, I didn't know how to measure "v". Took me ages cuz they made me do experiment 2 first (which took like 40 mins?) and made me wait 20 mins for using the 1st question's apparatus. effin gay. Rushed through the whole of question 1. Got all the values of v wrong. Rest was OKAY.
I hope I do well, but I can't say I did good nor can I say I did VERY bad.
OMG!! same here.. i had to do question 2 first and waited there for like 25mins.. and yes, rushed through question 1.. so my best fit line was absolutely horrible.. wanted to alter it but dont have enough time :( so we're seriously at a disadvantage..
Post by: falafail on November 03, 2009, 12:50:05 pm
Post by: heemvi on November 03, 2009, 12:56:58 pm
n the 1st question ws olryt...
2nd 1 a little iritatin.bt ws ohk
we didnt get on elctricity
Post by: Lana Wolf on November 03, 2009, 01:23:13 pm
i also did paper31....question 1 was bad...2nd was good...
anyone remembers their C value???? im really worried about tht part....
Post by: falafail on November 03, 2009, 01:25:53 pm
well i was only happy tht there was nothing related to electricity....
i also did paper31....question 1 was bad...2nd was good...
anyone remembers their C value???? im really worried about tht part....
ahh, i don't think we're supposed to discuss the actual questions this soon after the exam D:
but yeah, i wasn't sure about C either. i don't think you'd lose many marks though for the final value (maybe just 1), as long as you knew how to solve it and showed your working. :)
Post by: MaNi_DaDuDe on November 03, 2009, 01:39:31 pm
aww. i did question 1 first, and had to wait half an hour to start on question 2 :-\
Lies.
Post by: slammer951 on November 03, 2009, 01:58:38 pm
aww. i did question 1 first, and had to wait half an hour to start on question 2 :-\
Same here, question 1 was absolutely perfect for me!! The only thing i'm worried about is that my string had three marks on it instead of two so i asked my teacher which ones to use and i think he thought of it as me not knowing what to do so im worried he might deduct marks for him "helping" me :'(
Post by: Lana Wolf on November 03, 2009, 02:17:42 pm
ahh, i don't think we're supposed to discuss the actual questions this soon after the exam D:
but yeah, i wasn't sure about C either. i don't think you'd lose many marks though for the final value (maybe just 1), as long as you knew how to solve it and showed your working. :)
oh...sorry....forgot tht...lol :D
i showed all my working..but i dunno im still worried...
well i hope someone posts d answer atleast tomorrow..... :)
Post by: falafail on November 03, 2009, 02:22:07 pm
Lies.
i do not lie. >:(
Post by: falafail on November 03, 2009, 02:23:30 pm
Same here, question 1 was absolutely perfect for me!! The only thing i'm worried about is that my string had three marks on it instead of two so i asked my teacher which ones to use and i think he thought of it as me not knowing what to do so im worried he might deduct marks for him "helping" me :'(
I KNOW RIGHT!? my graph was perfectly straight line. it was brilliant ;D
i had some trouble with the marks too though, cos they sat me in front of the window and i couldn't see them properly because of the sun behind 'em. gay. :-\
oh and don't worry, you'd only lose one mark even if the invigilator thought you were getting help. :)
Post by: falafail on November 03, 2009, 02:24:21 pm
oh...sorry....forgot tht...lol :D
i showed all my working..but i dunno im still worried...
well i hope someone posts d answer atleast tomorrow..... :)
don't worry, i'm sure you get marks for the working even if it's wrong.. but hopefully it won't be^__^