Physics, Chemistry and Biology: Post your doubts here!

[sma786]

ummm as its more efficient ,,where is it asked?

w08 paper 31.. thanks, ur right =]

 

[sma786]

what is the timebase in CRO ?

 

[sma786]

State what is meant by the efficiency of a power station ?

 

[thats_me]

State what is meant by the efficiency of a power station ?

it is the amount of energy it gives as output divided by the amount of energy it take in

 

[sma786]

it is the amount of energy it gives as output divided by the amount of energy it take in

thanku =]

 

[thats_me]

thanku =]

which pprs r u solvin?

 

[sma786]

which pprs r u solvin?

may june 2008 =]

 

[thats_me]

may june 2008 =]

oh kk

 

[tribianni]

help Q5di http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s10_qp_31.pdf

 

[kboss]

HELP!!!
physics winter 2010 p 33!!!
question 2b
HELP!!!

 

[kainat husain]

PLEASE PLEASE SOME ONE HELP URGENT
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w06_qp_3.pdf
q-1 b (iv)
q-5b
q-6a, c
q-7a
q-8a
q- 9 c how to draw :/
q-10 c
and 11 a
plz plz plz help plz

 

[MERIHAN]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w10_qp_33.pdf

PLZ HELP ME IN QUESTION 10 (a) in the above attached link of the paper THANKS IN ADVANCE !!!!

 

[*MK*skydiver :D]

ummmm hello,,
I couldnt understand a question about logic gates in november 2011 Question 10 b ,, i dont understand how it works ....
Thanks in advance

 

[ThatReallyReallyWeirdDude]

PLEASE PLEASE SOME ONE HELP URGENT
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w06_qp_3.pdf
q-1 b (iv)
q-5b
q-6a, c
q-7a
q-8a
q- 9 c how to draw :/
q-10 c
and 11 a
plz plz plz help plz

q1-b (iv)The cork can't float, so therefore you have to include a method to make it stay underwater.The best way would be to tie a rock to it - however you'd have to find the volume of the rock first and subtract it
q-5b
The particles being subjected to heat gain kinetic energy and vibrate faster, causing them to knock the particles next to them and thus spreading the energy along. (Don't need to say, but for your benefit; the particles which get knocked also gain energy, vibrate, knock particles surrounding and further spread it etc. )
q6a)

q6c) There is no change because the rays are entering/exiting along the normal (i.e. angle of incidence = 0)
q7a)
First thing which is wrong: The wavelength of the diffracted waves is not constant/increases
Second thing which is wrong: It is not diffracted/not curved (should be curved)
q8a)

q9a)

q10c)When it goes dark, the resistance of the LDR is high
When it's high it gets a higher share of the voltage, and the transistor C gets the same amount of this voltage. Since the voltage is high now, transistor conducts/allows current to get to the lamp, and the lamp switches on.
q11a) Atoms will lose electrons when they interact with particles, thus causing them to become ions
ii)Multiple reasons: It has slower speed, so it can hit more particles
It has larger size so it can hit more particles
It has higher charge so it can take more electrons

I hope I helped you!

 

[ThatReallyReallyWeirdDude]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w10_qp_33.pdf

PLZ HELP ME IN QUESTION 10 (a) in the above attached link of the paper THANKS IN ADVANCE !!!!

You're supposed to use a compass to draw the three waves again centered around R. You shouldn't include the bit behind the solid barrier - that is the faded red lines on the diagram I made for you, but that's so you can understand.

 

[ThatReallyReallyWeirdDude]

ummmm hello,,
I couldnt understand a question about logic gates in november 2011 Question 10 b ,, i dont understand how it works ....
Thanks in advance

Link to the past paper please. There's three variants so...

 

[ThatReallyReallyWeirdDude]

HELP!!!
physics winter 2010 p 33!!!
question 2b
HELP!!!

Alright
It says that it JUST tips the scale; that means its JUST above equilibrium
So we can assume clockwise moments = anticlockwise moments
so moment caused by man = moment caused by planks weight
so 0.17xW = 0.78x160
W=(0.78x160)/0.17=734N.
That's what the mark scheme says

 

[kboss]

View attachment 10679

Alright
It says that it JUST tips the scale; that means its JUST above equilibrium
So we can assume clockwise moments = anticlockwise moments
so moment caused by man = moment caused by planks weight
so 0.17xW = 0.78x160
W=(0.78x160)/0.17=734N.
That's what the mark scheme says

thanks

 

[kboss]

View attachment 10679

Alright
It says that it JUST tips the scale; that means its JUST above equilibrium
So we can assume clockwise moments = anticlockwise moments
so moment caused by man = moment caused by planks weight
so 0.17xW = 0.78x160
W=(0.78x160)/0.17=734N.
That's what the mark scheme says

ur appearing for tmrw's ppr?

 

[ThatReallyReallyWeirdDude]

ur appearing for tmrw's ppr?

Yes