Author Topic: CIE physics paper 2  (Read 11820 times)

Offline happy angel

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Re: CIE physics paper 2
« Reply #30 on: November 15, 2009, 06:21:40 pm »
plzz help me with this one..

It is possible to use two separate oscillators feeding 2 loudspeakers to demonstrate interference of sound. It is not possible to use 2 filament lamps, however similar, to produce interference of light. explain this difference.

am not sure but abt the filaments la i fink its bcoz for interference to occur the sources must b monochromatic ie sme freq n wavelength wiv phase diff etc as i xplained above..
for the sound maybe the oscillators may be made to vibrate at the same freq so that interence occurs and the loudspeakers act as slits with d being the distance btwn the slits.. it will give the intensity of sound after interference ie soft or loud..wich rep the dark n bright fringes respectively..
i hope u und ;D :-[ ::) ??? 8)

Offline happy angel

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Re: CIE physics paper 2
« Reply #31 on: November 15, 2009, 06:31:03 pm »
oh sorry, i meant 4 (b) (i) 1 not 4 (a) D:
and um, all of it. i need someone to explain what affects separation/brightness of fringes etc

ah sory,, it must be comparable to wavelength.. so smfing relatively small eg 1mm
abt separation of fringes use the eqn B=(D times lamda)/d
were D is distance btwn double slit arrangement and screen
       d is separation of the 2 slits..

varying D and d ul see abt separation.
now intensity.
use I = k/r2
were r is the distance btwn 1st slit and the double slit..
wen r decreases I ie intensity increases.

ermm i managed to mk u und? a bit? ???

Offline saadiyah

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Re: CIE physics paper 2
« Reply #32 on: November 15, 2009, 06:45:23 pm »
am not sure but abt the filaments la i fink its bcoz for interference to occur the sources must b monochromatic ie sme freq n wavelength wiv phase diff etc as i xplained above..
for the sound maybe the oscillators may be made to vibrate at the same freq so that interence occurs and the loudspeakers act as slits with d being the distance btwn the slits.. it will give the intensity of sound after interference ie soft or loud..wich rep the dark n bright fringes respectively..
i hope u und ;D :-[ ::) ??? 8)

thx happy angel..i think i get it :D

Offline happy angel

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Re: CIE physics paper 2
« Reply #33 on: November 15, 2009, 06:49:43 pm »
thx happy angel..i think i get it :D


welcome dr... n thx u too 4 mking me revise.. hehe ;D

Offline happy angel

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Re: CIE physics paper 2
« Reply #34 on: November 15, 2009, 06:55:25 pm »
welcome dr... n thx u too 4 mking me revise.. hehe ;D

hey tell me in june 09 p2 the 1st ans wen u calculate error its 0.18.
in marking scheme its 0.09
y shud we divide by 2??
plzz tl meee :'( :-[

Offline Asif iqbal

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Re: CIE physics paper 2
« Reply #35 on: November 15, 2009, 08:54:13 pm »
Guys I've got this really cool list of  all the definations really good for final revision will hardly take ten minutes to read all of them where do I post them here or should I make a new topic for it??

Offline MaNi_DaDuDe

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Re: CIE physics paper 2
« Reply #36 on: November 15, 2009, 08:59:48 pm »
Guys I've got this really cool list of  all the definations really good for final revision will hardly take ten minutes to read all of them where do I post them here or should I make a new topic for it??


Hey :)

Just attach it here, thanks! :D

Offline falafail

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Re: CIE physics paper 2
« Reply #37 on: November 16, 2009, 04:07:38 am »
ah sory,, it must be comparable to wavelength.. so smfing relatively small eg 1mm
abt separation of fringes use the eqn B=(D times lamda)/d
were D is distance btwn double slit arrangement and screen
       d is separation of the 2 slits..

varying D and d ul see abt separation.
now intensity.
use I = k/r2
were r is the distance btwn 1st slit and the double slit..
wen r decreases I ie intensity increases.

ermm i managed to mk u und? a bit? ???
Wait so in that first equation whats B?

And the intensity is inversly proportonal to r2 then? Is that the only thing that a ffects the intensity?

Offline falafail

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Re: CIE physics paper 2
« Reply #38 on: November 16, 2009, 04:10:06 am »
hey tell me in june 09 p2 the 1st ans wen u calculate error its 0.18.
in marking scheme its 0.09
y shud we divide by 2??
plzz tl meee :'( :-[


I cant download the past paper right now but if you post the question i can probably help..

Offline falafail

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Re: CIE physics paper 2
« Reply #39 on: November 16, 2009, 08:02:30 am »
*censored*.

Offline Hwa1

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Re: CIE physics paper 2
« Reply #40 on: November 16, 2009, 08:04:43 am »
Just did it
was quite easy, only think i lost 5 marks
the spring question drove me nuts though..could get 0.077
wat did u guys get for phase difference?
also the wave thing...speed is..?
(im tryin not to expose too much lol)

Offline falafail

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Re: CIE physics paper 2
« Reply #41 on: November 16, 2009, 08:08:31 am »
I dont know, dont remember.
I lost like, 12-20 marks, at least :(

Offline MaNi_DaDuDe

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Re: CIE physics paper 2
« Reply #42 on: November 16, 2009, 08:32:24 am »
I dont know, dont remember.
I lost like, 12-20 marks, at least :(

Dude. You are not alone. I lost like 18 marks for sure.

The paper was soooooooo easy. However, the time. omfg. I thought we had 1 hour 15 mins like the other p2s so I was taking it easy. I couldn't do the electricity OR the waves question (NO TIME LEFT)! :( I did radiation in the last 2 mins, easy sh*t.

bleh :(

Offline Hwa1

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Re: CIE physics paper 2
« Reply #43 on: November 16, 2009, 08:35:20 am »
electricity was alryt, but there were a lot of calculations wich killed time
waves question i think i lost 2-3 marks
spring question was the real problem..
and the 1st question i dno if my significant figures were correct or not for my answers =-S

Offline josephwhite

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Re: CIE physics paper 2
« Reply #44 on: November 16, 2009, 08:38:59 am »
d paper was eashee...compared to paper 4, i guess :p :P

did not get the uncertainity question...so uncertain in my answer...then didnt get the 0.077 J spring.... good thing get 1 mark only..

CIE becomes scrooge mcduck in this paper...tighwad in givin marks... lol