physics paper 1 2011 discussion

[amaghraby]

some one please explain to me the barometer question....
for thoose who didn't sit for the exam dun ask what was it b4 24 hrs
sanks and beace

 

[tripleA95]

I wrote that they both had equal pressures. :/

 

[amaghraby]

atmospheric or the same pressure at x and y ?

 

[Ahmooosh]

i wrote x is less than y in terms of pressure , but i think am wrong,
which bulbs are switched on off , in order on off on?
or all on ?
also the how to find the N of magnet , wat do u do?

hope u all did well , maths was hard today...

 

[WayneRooney10]

use compass for that magnet
all lamps are on
Same atm. pressure on both day

Yeap MATHS was pretty hard :shock:

 

[Keeemoman]

atmospheric pressure were the same
and all the lamps will glow on
and a tricky one was the transformer, the primary coil is the one in your right.

 

[tripleA95]

Yeah I got them correct except the lamps Math was really easy.
What'd you get for the ice? 0 or 2

 

[Ahmooosh]

all lamps were on? haha we had this huge debate after the exam , some argue that on of on , and others on on on ,.....
they are saying that since the current was D.C
then the path was one direction only , so it cant pass through the second bulb because it wont go down * since its dc* to flow through the branched wire on the left side... dunno wats right ,
hope maths curve goes waaaaaaaaaaaay down...

 

[Ahmooosh]

Ice = 0
maths was easy?? :S wat variant did u do?

 

[MarkBobbyChandy]

i made a mistake on the transformer one. other than that nd the lamp question, everything was pretty straight forward.

 

[tess128]

the barometer i did they both have same atmospheric pressure
and the lamps on off on
the primary coil was the one on the right??! :S

 

[adityar]

I don't mean to be rude or anything, but WHY would he pressures be equal?! That's impossible because the right barometer had a bigger test tube, so the right one should have more pressure, right?

 

[Ahmooosh]

yea i wrote the one on right , and i hope the on off on is correct xD
barometer got em wrong..
it was the hardest paper 1 so far... not too hard , just harder than the rest...

 

[Rahma Magdy]

ummm.. Guys..
What about the question with the converging lens?

 

[adityar]

I wrote x had less pressure because in y there was more mercury, meaning more pressure in the deep... What was the extension question; I wrote 300...

 

[ali123456789]

image is inverted !

 

[Ahmooosh]

i wrote inverted for the lens , hope thats right....
i wrote 200 for extension... not sure though
and adityar i thought same thing for barometer question so i wrote that dunno why its wrong though...

 

[adityar]

yea i wrote the one on right , and i hope the on off on is correct xD
barometer got em wrong..
it was the hardest paper 1 so far... not too hard , just harder than the rest...

the answer is on on on 'cause though there is a broken circuit, current is still going through the second one via the parallel circuitry... I agree, the past papers were easier...
:evil: :evil: :evil: :twisted: :twisted: :twisted:

 

[burndtjamb]

The thing with the barometer question is that liquid pressure is affected by 3 things only: density of the liquid, gravitational acceleration, and the depth of the liquid.

Both X and Y were at the same depth, and since the density of mercury and gravitational acceleration is constant the pressure at points X and Y should be equal.

 

[adityar]

i wrote inverted for the lens , hope thats right....
i wrote 200 for extension... not sure though
and adityar i thought same thing for barometer question so i wrote that dunno why its wrong though...

NOOOOOOOOOOOOOOOOOOO!!!!!! The answer is RIGHT I could not think of any other possible thing because they CERTAINLY did not have same pressures due to volume difference, so that rules out B and D, and x DID have lesser prssure, so me and you have to be right