physics paper 33

[shahyAmr]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w08_qp_31.pdf
sorry *question 1g ??

p is equal to the gradient you calculated in part (f)

 

[7devilsallaround]

p is equal to the gradient you calculated in part (f)

Kay...and in the next part, -p/q = y intercept? so q will come out -ve right?

 

[Ammar Naeem]

Parralax error in reading the thermometer, one reading is not sufficent for an accurate result, imprecise thermometer, external conditions like air might cause temperature change
Improvements: Avoiding parralax error, taking more than one reading(average), use of thermocouple as a more accurate thermometer, performing the experiment in such an environment that external conditions are reduced to minimum.

 

[shahyAmr]

Can't be quite sure unless I see an example question but these are usually accepted:
Errors: heat loss thru walls of container, water evaporates, and idk know to phrase this but its like human reaction error or something when you have to take a temperature reading and the corresponding time reading
Improvs: Insulation, lid, data loggers
If anyone has more please share.

look at the answers for nov11 ppr35 Q2 part(h) .. you can see the possible limitations and imp. there

 

[7devilsallaround]

look at the answers for nov11 ppr35 Q2 part(h) .. you can see the possible limitations and imp. there

Yep, lookin thru those now thnx.
Also in the same mark scheme, they say to draw a conclusion about proportionality of k "tested against a suitable criterion by the student." Whats this mean?

 

[shahyAmr]

Kay...and in the next part, -p/q = y intercept? so q will come out -ve right?

may be it will be negative or maybe the value of the yintercept is already negative so when u calculate it q will be positive

 

[shahyAmr]

Yep, lookin thru those now thnx.
Also in the same mark scheme, they say to draw a conclusion about proportionality of k "tested against a suitable criterion by the student." Whats this mean?

i have no idea .. they write this in all exams and i dnt undrstant it at all !!!

 

[7devilsallaround]

Ok in the last part of Q1 where we find the gradient intercepts and constants, if the eqn is like "a = c/d - e/f" and you get a -ve intercept FROM THE GRAPH, do we replace e/f with " - intercept" to get +ve value, or just "intercept" because there already is a - in front of the e/f?
Ugh this is so confusing idk if I've explained it right...

 

[shahyAmr]

Ok in the last part of Q1 where we find the gradient intercepts and constants, if the eqn is like "a = c/d - e/f" and you get a -ve intercept FROM THE GRAPH, do we replace e/f with " - intercept" to get +ve value, or just "intercept" because there already is a - in front of the e/f?
Ugh this is so confusing idk if I've explained it right...

replace -e/f by the negative y-intercept .. so both the negative signs will now cancel each other out

 

[7devilsallaround]

replace -e/f by the negative y-intercept .. so both the negative signs will now cancel each other out

Keep the signs for both eqn and intercept, got it tyvm 8D

 

[shahyAmr]

Keep the signs for both eqn and intercept, got it tyvm 8D

np

 

[7devilsallaround]

i have no idea .. they write this in all exams and i dnt undrstant it at all !!!

Been lookin thru forums and there's different methods...
To find the % uncertainty its either "k2-k1/k2 x 100" or "k2-k1/k1 x 100" to find % uncertainty of k. My logic says to use k1 in denominator, cuz that'll give the greatest possible uncertinty...
They also say to compare that with a 20% uncertainty reference value.
Ppl say if its >20% its proportional, but others say its proportional if <2%.
Sooo...confused...

 

[shahyAmr]

Been lookin thru forums and there's different methods...
To find the % uncertainty its either "k2-k1/k2 x 100" or "k2-k1/k1 x 100" to find % uncertainty of k. My logic says to use k1 in denominator, cuz that'll give the greatest possible uncertinty...
They also say to compare that with a 20% uncertainty reference value.
Ppl say if its >20% its proportional, but others say its proportional if <2%.
Sooo...confused...

Ugg!!! this is really confusing :s .. but you're right logic says that the denominator should be k1 but then how do we know if it's proportional or not ?? which one is right ??
btw mmm is asked someone who said that you could jst look at the values of k and if thy r the same then thy r proportional if thy r different thn thy r nt ... I'm nt sure of this but it's alot easier

 

[airfantahir]

Hey guys what's the weightage of this paper?

 

[7devilsallaround]

Ugg!!! this is really confusing :s .. but you're right logic says that the denominator should be k1 but then how do we know if it's proportional or not ?? which one is right ??
btw mmm is asked someone who said that you could jst look at the values of k and if thy r the same then thy r proportional if thy r different thn thy r nt ... I'm nt sure of this but it's alot easier

xD Ik that method, its what I've been using in lab class and mocks: if both k's are approximately equal then they are proportional. That's teacher approved actually. But then I saw these posts and the mark scheme also said "test against suitable criterion" and now idkkkkk D:

 

[shahyAmr]

Hey guys what's the weightage of this paper?

23%

 

[airfantahir]

Thanks shahyAmr. Good luck to all who's giving 33 today. Seems quite easy. But you never know.

 

[shahyAmr]

xD Ik that method, its what I've been using in lab class and mocks: if both k's are approximately equal then they are proportional. That's teacher approved actually. But then I saw these posts and the mark scheme also said "test again suitable criterion" and now idkkkkk D:

hahahaha
then jst use this way cuz its alot easier and less confusing plus the person I asked knows how to solve these questions very well so i think i'll use ths method

 

[7devilsallaround]

Can someone run me thru how to use micrometer and verniers plz?

 

[cHeStEr]

when we find out Y-Intercept and the gradient .... do we have to mention its units too????