Biology; Chemistry; Physics: Post your doubts here!

[falcon678]

dont be sad... im not even have enough time to think about it... i waste too much time on the graph and i not feeling well today... waste too much time to understand the question... hope no calculation mistake....

the graph waz reali awkward..!!!

 

[Fallen316]

the graph waz reali awkward..!!!

why ?

 

[fatima360]

somebody plxxx tell me the experiment to find critical angle :

 

[falcon678]

why ?

it waz nt a smooth graph...... a sort of hump waz forming on 2nd last plot...!!

 

[Fallen316]

it waz nt a smooth graph...... a sort of hump waz forming on 2nd last plot...!!

seriously ? , mine was pretty smooth.

 

[Ahmedfj]

blue

bcuz the concentration is not changing and amount of copper ions are still in the solution ..!!

but the electrodes are of copper and the solution is of copper salt so wouldnt the copper deposit on cathode ???

 

[daredevil]

but the electrodes are of copper and the solution is of copper salt so wouldnt the copper deposit on cathode ???

the blue colour is of the solution. what happens is that Cu2+ ions from the solution deposit on the cathode, thus reducing the concentration of the solution. but the anode dissolves to becomes ions and replaces those ions and restores the concentration... thus maintaining the colour too. (the colour of the soluion gets pale if the solution becomes dilute but here the solution remains of the same oconcentration so no change in colour.) hope it heled

 

[Ahmedfj]

the blue colour is of the solution. what happens is that Cu2+ ions from the solution deposit on the cathode, thus reducing the concentration of the solution. but the anode dissolves to becomes ions and replaces those ions and restores the concentration... thus maintaining the colour too. (the colour of the soluion gets pale if the solution becomes dilute but here the solution remains of the same oconcentration so no change in colour.) hope it heled

thanks a lot dude

 

[Tayyab Muzafar]

CHEISTRY ATP... could you have written a precaution other than using a PIPPETE FILLER?...(gloves maybe)

 

[Tayyab Muzafar]

can anybody tell me an experiment to find critical angle(using an appropriate appratus)??

Use a ray box to project a light beam unto a semicircle shaped glass block. Move the ray box around the semicircle until angle of refraction is 90. DONE

 

[syed1995]

CHEISTRY ATP... could you have written a precaution other than using a PIPPETE FILLER?...(gloves maybe)

I wrote Gloves!

 

[fatima360]

cud it be a safety bulb?

I wrote Gloves!

 

[syed1995]

cud it be a safety bulb?

that was the correct answer. But the question here is can Gloves work as well or not?

 

[Tayyab Muzafar]

cud it be a safety bulb?

The correct ans. was a safety bulb (most of my friends wrote it)... I wrote GLOVES but the thing is this quostion was asked in M/J 2004 and the marking scheme says "glass bulb"

 

[snoonono]

guys can some1 give me a list of all laws we need for physics paper 3????
Would be really grateful to who would give me, and thanks in advance

 

[ayeshaK]

http://www.xtremepapers.com/papers/...onal O Level/Physics (5054)/5054_s08_qp_1.pdf
Mcq no 13 and 30 with explanation please

 

[haha101]

30B
13 A

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf
Mcq no 13 and 30 with explanation please

 

[Tayyab Muzafar]

I wrote Gloves!

Same here but i dnt knw if its rit...

 

[Fallen316]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Physics (5054)/5054_s08_qp_1.pdf
Mcq no 13 and 30 with explanation please

13.A
since pressure is inversly proprtional to volume, P*V = k ( constant value )
now you multiply , in each option , the pressure with the volume
b,c,d's constant is 4800 , while a's constant is 4320.
30.B
in series , the current remains the same while in parallel the current divides.

 

[khizer shahab]

but the electrodes are of copper and the solution is of copper salt so wouldnt the copper deposit on cathode ???

yes it will deposit on cathode

as the copper in electrolyte start moves to cathode the copper deficiency in electrolyte is recovered by the copper at anode ..if one ion of copper moves to cathode then one ion will be deducted from copper anode ...therefore the amount of copper remains the same thus color would not change !!!

hope you got it