Physics: Post your doubts here!

[hassanhijazi1995]

HAVE ANYONE DONE THE PHYSICS P.2 AS???
do u remember yhe answers plz tell me

 

[Soldier313]

Mind helping me with June 2002 for alternating current?

hey i looked into it
but i don't get the bit about the pulses, sorry :/

 

[Troubled soul]

Can anyone give me or upload an already done practical phy paper , 33. With readings and all?

 

[fakibaz]

I have my paper 3 practicals coming up and i am very confused about the significant numbers and decimal places to be used !! I've heard that for raw data we keep the decimal places same while for calculated data we keep the significant numbers same. Is it so? And also calculated data are same or one more sf than raw data.Then what if i have raw data readings in 2 sf and 3 sf both but both are in same dp...what sf will i choose for calculated data?!!

 

[aleezay]

I have my paper 3 practicals coming up and i am very confused about the significant numbers and decimal places to be used !! I've heard that for raw data we keep the decimal places same while for calculated data we keep the significant numbers same. Is it so? And also calculated data are same or one more sf than raw data.Then what if i have raw data readings in 2 sf and 3 sf both but both are in same dp...what sf will i choose for calculated data?!!

Yes you are right.. go for 3sf if thats the case. Since calculated values must have the same no./one more no. of sf as compare to that of raw data..

 

[aleezay]

For P3, the part on percentage uncertainty troubles me alot.. If we measure two values, each with uncertainty .1cm, and calculate their average, would the absolute error in the calculated value be .2 or .1? Also, if the diameter of a tube has an uncertainty of .1cm, what would be the uncertainty in the radius? .1cm? Thirdly, how would we know if we are to give angles to the nearest degree or to half a degree? Is there some set rule? Please help me with this asap. Thanks in advance
One more thing: Would they take away the apparatus for q1 after an hour or would we have both sets of apparatus till the end? And any tips for the paper?

 

[fakibaz]

Yes you are right.. go for 3sf if thats the case. Since calculated values must have the same no./one more no. of sf as compare to that of raw data..

thanks!!

 

[Osaid Zahid]

AOA
Can someone answer my query.... Light is made of photons (packets of energy) right and is Wave also a part of electromagnetic spectrum ... So are all types of waves within the electromagnetic spectrum made of photons ? Or what is exactly an electromagnetic wave . How might electrons , energy or photons be made into a wave .
O'L student.

 

[XD boy]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w07_qp_4.pdf
Help, in question 5 part b (ii). How does area equal to 21.2 cm^2 ?

 

[hela]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w12_ms_31.pd

sensible comment relating to the calculated value of K testing i\against criterion specified by candidate what do they mean by CRITERION ?? in P31 O/N2012

 

[Atiqa asl]

Sum1 plzzxz tell me whst is cuming in phy paper31

 

[1357913579]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w10_qp_41.pdf
number-2b(iii) for the (ii) we calculated work done by area under the graph and got 240 not for calculating the work done for Q--->R how is the work done=0 which s given in the question?
and also for calulating the work done from R--->P why cant we do area under the graph and get??
please help

 

[Jinkglex]

everyone has questions but noone has answers it seems

 

[1357913579]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w11_qp_43.pdf
1(c)(ii) what do we write for this?
because what i think is that answer should be is he hydrogen molecules dont have enough kinetic energy to move in mars so they escape they dont have enough k.e becuase they dont have enough temp as both ase proportional whats wrong in this answr??
please help

 

[fakibaz]

For P3, the part on percentage uncertainty troubles me alot.. If we measure two values, each with uncertainty .1cm, and calculate their average, would the absolute error in the calculated value be .2 or .1? Also, if the diameter of a tube has an uncertainty of .1cm, what would be the uncertainty in the radius? .1cm? Thirdly, how would we know if we are to give angles to the nearest degree or to half a degree? Is there some set rule? Please help me with this asap. Thanks in advance
One more thing: Would they take away the apparatus for q1 after an hour or would we have both sets of apparatus till the end? And any tips for the paper?

if you calculate the average the absolute value would still stay .1cm also for diameter and radius it will be the same absolute error...this is because you are using the same instrument for measurig the values. i dont know about the angle though ..and they'll take the apparatus after an hour as far as i have heard

 

[aleezay]

if you calculate the average the absolute value would still stay .1cm also for diameter and radius it will be the same absolute error...this is because you are using the same instrument for measurig the values. i dont know about the angle though ..and they'll take the apparatus after an hour as far as i have heard

But ive come across several marking schemes in which they take the uncertainty of the averaged value as .2.. but at the same time there are many others in which they take it as .1.. pretty confused.. :/

 

[hela]

sensible comment relating to the calculated value of K testing i\against criterion specified by candidate what do they mean by CRITERION ?? in P31 O/N2012

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w12_ms_31.pd

 

[xxfarhaxx]

qustn 1-c.. hw did they get 1.94*10^7???
http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s03_qp_4.pdf
http://papers.xtremepapers.com/CIE/...el/Physics (9702)/9702_s03_ms_1+2+3+4+5+6.pdf

 

[hela]

sensible comment relating to the calculated value of K testing i\against criterion specified by candidate what do they mean by CRITERION ?? in P31 O/N2012

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_w12_ms_31.pd

 

[fakibaz]

But ive come across several marking schemes in which they take the uncertainty of the averaged value as .2.. but at the same time there are many others in which they take it as .1.. pretty confused.. :/

why bother about it actually? if you have repeated readings then finding percentage uncertainity is (1/2 of highest reading - lowest readig)/avg reading x 100