IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: joel on May 20, 2011, 07:15:21 am

Title: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: joel on May 20, 2011, 07:15:21 am
Could anyone do the October/November 2002, Paper 5, Question 2.

Link to question paper -

http://www.xtremepapers.me/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_w02_qp_5.pdf
 (http://www.xtremepapers.me/CIE/index.php?dir=International%20A%20And%20AS%20Level/9702%20-%20Physics/&file=9702_w02_qp_5.pdf)

Thanks!
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: joel on May 20, 2011, 07:28:54 am
All the design questions from May/June 2002 to October/November 2006 are really tricky.
So I you guys don't mind, can you upload your answers if you have done those questions.
I am also attaching a pdf document containing all the design questions from June 2002 to November 2006.

Please reply soon!
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 20, 2011, 03:19:29 pm
Just a heads up... people may take a while to reply.. because if theyre like me- they havent done the papers before 2006.  :-\

But I'll have a go anyways :D. In simple.. for the experiment I'd probably have a signal generator attached to a vibrator connected to the string. The string would be in a pulley system with a known wieght attached to the end (can find tension from that). For different masses (tensions), vary the vibrations until a max amplitude is seen.. the frequency that it occurs at is the resonant frequency. Record the resonant frequency and tension.. construct a graph- tension on x-axis and frequency on y-axis. right? And the controls- same mass per unit length of wire.. same length of wire (basically same wired used) for each tension... but the thing im stuck on is -would you have to change the lengths to keep it at the fundamental mode for each tension?? TBH- i cant remember what the fundamental node is.  :P and safety - i dont know?- maybe ear protection incase of high pitch frequencies?

hope i helped in some way. sorry if its vague.. its just off the top of my head.
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 21, 2011, 02:45:46 pm
how can u find the tension from the weights?
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 21, 2011, 03:07:58 pm
how can u find the tension from the weights?

dont know.. google it.  :P

Im pretty sure its got something to do with the weight. ?
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 21, 2011, 03:13:45 pm
cant we just turn the pegs of a guitar and attach a newton meter to it?
secondly can someone PLEASE explain ON09 P51 q1 and with a diagram if possible please! =(
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 21, 2011, 03:33:38 pm
cant we just turn the pegs of a guitar and attach a newton meter to it?
secondly can someone PLEASE explain ON09 P51 q1 and with a diagram if possible please! =(


that actually seems smarter :P .. how do you find the frequency tho?

And what exactly do you need help in that?.. its easier that way. instead of writing up the whole thing- cause you could just look at the marking scheme?

I attached a paint version of the diagram I drew which my teacher said was okay.
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 21, 2011, 03:36:01 pm
Just a heads up... people may take a while to reply.. because if theyre like me- they havent done the papers before 2006.  :-\

But I'll have a go anyways :D. In simple.. for the experiment I'd probably have a signal generator attached to a vibrator connected to the string. The string would be in a pulley system with a known wieght attached to the end (can find tension from that). For different masses (tensions), vary the vibrations until a max amplitude is seen.. the frequency that it occurs at is the resonant frequency. Record the resonant frequency and tension.. construct a graph- tension on x-axis and frequency on y-axis. right? And the controls- same mass per unit length of wire.. same length of wire (basically same wired used) for each tension... but the thing im stuck on is -would you have to change the lengths to keep it at the fundamental mode for each tension?? TBH- i cant remember what the fundamental node is.  :P and safety - i dont know?- maybe ear protection incase of high pitch frequencies?

hope i helped in some way. sorry if its vague.. its just off the top of my head.
how would u measure the resonant frequency?
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 21, 2011, 03:38:19 pm
that actually seems smarter :P .. how do you find the frequency tho?

And what exactly do you need help in that?.. its easier that way. instead of writing up the whole thing- cause you could just look at the marking scheme?
actuallyy i wouldnt apply the guitar method cuz turning the pegs would vary the length of the wire. ur way is better, but i dont underatnd how u wud calculate the frequency? secondly i dont understand the marking scheme for ON09 , so if u cud gimme a diagram, it'll be very helpful. =)
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 21, 2011, 03:51:27 pm
The signal generator thing would give you the frequency? .. or.. you attach that to a CRO with a known timebase scale- and read off that?

I edited my previous post with a shifty diagram. lol. its easier than getting my scanner out.  :D
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 21, 2011, 04:07:38 pm
yeah i guess u cud read off the frequency that gave off max amplitude oscillation from the signal generator. and thanks for the diagram! ur a life saver! =D
one more thing, what is ur dependent and indepenedent variable in the ON09 question?
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 21, 2011, 04:11:38 pm
I took resonant frequency as dependent.. and volume as independent.
so f2 on y-axis and 1/V on x-axis.
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 21, 2011, 04:13:32 pm
thankyouu soooooo effing much! =D =D =D
+rep =D =D
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: TJ-56 on May 22, 2011, 10:44:45 am
May June 2010 Paper 5, question 1, what should we draw exactly for the diagram?
Can someone help with this and post their drawing if possible?
Really appreciate the help.
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 22, 2011, 11:40:50 am
51 or 52?
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: TJ-56 on May 22, 2011, 11:42:54 am
51 or 52?

Sorry about that, its paper 52, the one with the circular coil.
And thank you for helping out :) .
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aldehyde1612 on May 22, 2011, 12:19:30 pm
sorry its really crappy... again. lol.

um.. basically try and show that the hall probe is positioned at right angles to the flux coming through the coil, like 3D- it would take me forever to do that on paint- sorry.  :-\
I took the hall probe image from what was in a paper 4 question. Remember to mention the current through the probe is constant.... i dont know if thats needed for this - but in the diagram i drew that my teach checked - i drew like this flat square sheet like thing connected to a Volmeter across one side and a power supply across the other side (if that makes sense?), and labelled it 'precalibrated hall probe' ... and the only correction on that was to 'state a constant current thru probe'. 
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: TJ-56 on May 22, 2011, 01:38:04 pm
Thank you so much for the help, dont worry, its perfect, just what I wanted.
+rep  ;)
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: aloha32 on May 22, 2011, 05:45:23 pm
guys! have you done nov 07 p5? how do u find out the error for the y intercept? and value for k? I just got a point off my values, subsituted for best fit gradient and worst fit gradient and subtracted the two and got the error. Is that right?

I got -.104 +- .0272 and .510 +- .025 for k .is that close? and are the numberz for sf ok for the errors?
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 22, 2011, 06:03:14 pm
i did not get any numbers that u are saying for any question, but yes ur method is ryt. =)
Title: Re: A2 CIE PHYSICS (9702) - PAPER 5 - DESIGN QUESTION
Post by: leebux101 on May 22, 2011, 06:24:20 pm
does anyone know how to calculate the fundamental frequency of , eg, an empty jar. PLEASE i reallyyy need this!!!!!!!!!  :(