ALL PHYSICS DOUBTS - POST HERE !!

[Ghost Of Highbury]

Where did u guys got the 3 and 16 from..? confused
N we are calculationg resistance ryt? not current?

ci) 1/1.8 + 1/1.8 = 1.111...1/1.11 = 0.9

ii) When in parallel, they both will receive 12V...however, the lamp are deigned to work at 6V supplu/ they may get damaged due to overheating..

[J.Darren]

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

7 b)

- water molecules from the bowl gets evaporated
- it condenses on the cloth, making it damp
- the hot air evaporates the water vapours on the damp cloth covering the milk bottle instead of the milk
- the milk bottle is kept cool as it is not evaporated / does not turn bad as it gets heated up

10 c) 1/1.8 + 1/1.8 = 1/R

[J.Darren]

read the question , u gotta calculate the current.

V = I*R

R = V/I

THe combined resistance of the two resistors(8 ohms and 16ohms) supposed to be arranged in parallel are

1/R = 1/8 + 1/16

therefore, 1/R = 3/16

R = 16/3 = 5.33ohms

R = 5.33
V = 12

thus I = V/R = 12/5.33 = 2.25A

I think ang3l is referring to the second variant

[J.Darren]

Regarding c ii) It would be unwise to connect them in parallel as the voltage would be too large.

[Ghost Of Highbury]

I think ang3l is referring to the second variant

OOPS!

[Malak]

Lol...Yeah...! Second variant...
M like...Wat question are they answering to...lmao...

[Malak]

7 b)

- water molecules from the bowl gets evaporated
- it condenses on the cloth, making it damp
- the hot air evaporates the water vapours on the damp cloth covering the milk bottle instead of the milk
- the milk bottle is kept cool as it is not evaporated / does not turn bad as it gets heated up

10 c) 1/1.8 + 1/1.8 = 1/R

Yeah i did that...and my answer is 1.111.. in ms its 0.9 ?

[WARRIOR]

Yeah i did that...and my answer is 1.111.. in ms its 0.9 ?

dont leave it like that

you have to find the inverse!

do 1/1.11



CAZ ITS 1/R = 1.111

SO WE MAKE R=1/1.11

[Malak]

dont leave it like that

you have to find the inverse!

do 1/1.11



CAZ ITS 1/R = 1.111

SO WE MAKE R=1/1.11

Ohkey....Thx

[Adzel]

http://www.xtremepapers.net/CIE/index.php?dir=Cambridge%20IGCSE/0625%20-%20Physics/&file=0625_w02_qp_3.pdf

Last Q Part (a), (b) and (c) + elplaination please...

as for attached...which one is right and why

[Vin]

http://www.xtremepapers.net/CIE/index.php?dir=Cambridge%20IGCSE/0625%20-%20Physics/&file=0625_w02_qp_3.pdf

Last Q Part (a), (b) and (c) + elplaination please...

as for attached...which one is right and why

for mcq paper its "B"
time taken for HALF the count rate from the original "140" .. half i.e "70" lies between 40 and 60

Q 10 c) after 20 days .. only little part of the original is left ..
d) beta decay is always  -1e and +1 proton


^A_ZX  ?    -1e     +  ^A_Z+1Y

[J.Darren]

for mcq paper its "B"
time taken for HALF the count rate from the original "140" .. half i.e "70" lies between 40 and 60

Definition for half-life : Time it takes for a radioactive material to halve its size in a radioactive decay.

[Adzel]

Thanks VIN...but could you explain more on part (b) please

[Vin]

Thanks VIN...but could you explain more on part (b) please

ok sure .. now wat u do is  .. u take the half of "50" (25) and plot a point on 8 because for 50 half life was 4 .. then then half of "25" (12.5) and plot on 16 and extend the curve along these points .. got it ??

[Adzel]

Not yet...this part,

then then half of "25" (12.5) and plot on 16 and extend the curve along these points .. got it ??

Why is it on 16?