Author Topic: ALL PHYSICS DOUBTS - POST HERE !!  (Read 228832 times)

Offline WARRIOR

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #960 on: May 22, 2010, 01:34:55 pm »
http://www.freeexampapers.us/IGCSE/Physics/CIE/2007%20Jun/0625_s07_qp_1.pdf

27) u guys told me that plotting compasses always point to North. Well i chose A, but its B... WHY? Plz explain clearly :S

http://www.scienceteacherprogram.org/physics/Omoloju04_files/image002.jpg

magnetic field is from north to south

the compass north follows the magnetic field.
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
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Offline WARRIOR

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #961 on: May 22, 2010, 01:35:50 pm »
wats given in the ms ?? i got it by fluke .. now im getting 170 ?? anything given in the ms ??

160 in mark scheme

how?? daymn..i thik u jsut extend it and measure the angle?
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #962 on: May 22, 2010, 01:37:25 pm »
160 in mark scheme

how?? daymn..i thik u jsut extend it and measure the angle?

try doing tht .. u get 160 ??

Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #963 on: May 22, 2010, 01:38:04 pm »
http://www.freeexampapers.us/IGCSE/Physics/CIE/2007%20Jun/0625_s07_qp_1.pdf

27) u guys told me that plotting compasses always point to North. Well i chose A, but its B... WHY? Plz explain clearly :S

dude always the back of the magnet points at North

Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #964 on: May 22, 2010, 01:39:00 pm »
160 in mark scheme

how?? daymn..i thik u jsut extend it and measure the angle?

u got it .. im getting 170

Offline Baladya

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #965 on: May 22, 2010, 01:41:48 pm »
dude always the back of the magnet points at North

OMG THOSE NOOBS  >:D  I knew it was like that but some noobs told me its the other way -.- 0.0
Anyway thx Kimo and Vin :)
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Offline Malak

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #966 on: May 22, 2010, 05:19:39 pm »
http://www.freeexampapers.us/IGCSE/Physics/CIE/2009%20Jun/0625_s09_qp_3.pdf
(Second variant)

Q4: Part a (all)

Q7: part b

Q10: part c.. Is there a different formula to calculate R...I used 1/R + 1/R?

Thx
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Offline Vin

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #967 on: May 22, 2010, 05:30:45 pm »
ok for 4 a) it'll take some time .. hold on..

7) b) ok molecules with high energy evaporate, when water evaporates it takes the heat energy with it .. i.e. heat is required to evaporate the water so this heat is "taken" from the milk this is the after effect of water evaporation.. also the cloth soaks up water constantly.

10 ) c) 1/R1 + 1/R2 is the one
also there is another one R1 × R2 / R1 + R2

« Last Edit: May 22, 2010, 05:42:31 pm by ~VIN1094~ »

Offline WARRIOR

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #968 on: May 22, 2010, 05:34:43 pm »
http://www.freeexampapers.us/IGCSE/Physics/CIE/2009%20Jun/0625_s09_qp_3.pdf
(Second variant)

Q4: Part a (all)

Q7: part b

Q10: part c.. Is there a different formula to calculate R...I used 1/R + 1/R?

Thx
 first questioni cant explain 4 caz i have to draw it :
This is becaus of evaporation ( remember occurs at any temperature )  ! we all know evaportation causes cooling ! so now the  the cloth is damp by water at room temperature !!! water molecules on cloth with most kinetic enrgy will escape  adn brake bonds from other water molecules. This leaves the molecules with least K.e in the cloth !!! So avergae KE is less and so the temperuter decrease!

and lastly the resitors I DUNNO ABOUT ANY OTHER FORUMLA but i used 1/r + 1/r and it was fine
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
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Offline Ghost Of Highbury

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #969 on: May 22, 2010, 05:37:44 pm »
http://www.freeexampapers.us/IGCSE/Physics/CIE/2009%20Jun/0625_s09_qp_3.pdf
(Second variant)

Q4: Part a (all)

Q7: part b

Q10: part c.. Is there a different formula to calculate R...I used 1/R + 1/R?

Thx

draw the scale diagram as shown

1cm = 500N
4000N(A) = 8cm

2000N(B) = 4cm

draw the parallelogram ..the diagonal is the resultant force..11cm shud be the diagonal's length.

11cm = 500*11 = 5500N ..

measure the length of the diagonal and calculate the force accordingly

measure the angle

shud be

-> 5500N
--> 30o


« Last Edit: May 22, 2010, 05:41:12 pm by A@di »
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Offline Malak

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #970 on: May 22, 2010, 05:44:04 pm »
 first questioni cant explain 4 caz i have to draw it :
This is becaus of evaporation ( remember occurs at any temperature )  ! we all know evaportation causes cooling ! so now the  the cloth is damp by water at room temperature !!! water molecules on cloth with most kinetic enrgy will escape  adn brake bonds from other water molecules. This leaves the molecules with least K.e in the cloth !!! So avergae KE is less and so the temperuter decrease!

and lastly the resitors I DUNNO ABOUT ANY OTHER FORUMLA but i used 1/r + 1/r and it was fine

And wat was ur answer?...Wat values did u use for r..? cuz m gettin a wrng answer ???

N thx all for answering :)
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Offline WARRIOR

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #971 on: May 22, 2010, 05:47:03 pm »
And wat was ur answer?...Wat values did u use for r..? cuz m gettin a wrng answer ???

N thx all for answering :)

The asnwer should be 5.33 A


u add them up..it will be 3/16 then u take the inverse of it which is 16/3 and then divide

remember the form is  1/R ( TOTAL RESISTN ) = 1/8 + 1/16

so you have to switch 1/R to be R
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
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Offline Ghost Of Highbury

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #972 on: May 22, 2010, 05:50:23 pm »
The asnwer should be 5.33 A


u add them up..it will be 3/16 then u take the inverse of it which is 16/3 and then divide

remember the form is  1/R ( TOTAL RESISTN ) = 1/8 + 1/16

so you have to switch 1/R to be R

shud be 2.25 Amperes, not 5.33 Amperes.

1/R = 3/16

R = 16/3 = 5.33ohms

V = IR

12 = I*5.33

I = 12/5.33

 = 2.25 A

4aii) attached
« Last Edit: May 22, 2010, 05:52:17 pm by A@di »
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Offline WARRIOR

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #973 on: May 22, 2010, 05:52:17 pm »
shud be 2.25 Amperes, not 5.22 Amperes.

5.33 ohms..12/5.33 = 2.25 A
i meant 5.33 ohms :P

oops i forgo to 2calulate Amps
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Offline Malak

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Re: ALL PHYSICS DOUBTS - POST HERE !!
« Reply #974 on: May 22, 2010, 06:02:17 pm »
Where did u guys got the 3 and 16 from..? ??? confused
in MS it say 0.9?
« Last Edit: May 22, 2010, 06:04:29 pm by ang3l »
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