Biology; Chemistry; Physics: Post your doubts here!

[funky brat]

"only made live when it does not have an Earth wire" != "charges go away through the Earth Wire"
We are assuming there is no earth wire thus there is a shock. Also the question does not state that there is an earth wire.

So you think it can be correct?

 

[Faizan Muhammmad]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s10_qp_41.pdf
In question 1(g), can't we say that the case of the kettle might become alive and the child can get an electric shock therefore it is not sensible to touch it?

alive?
Transformers: Revenge of the Undead Kettles

 

[funky brat]

alive?
Transformers: Revenge of the Undead Kettles

Physics has blown my mind.

 

[funky brat]

Do you know what is meant by
'the case is live'. It means that if you touch it, you will get an electric shock
Also how can an electric kettle not have a fuse?

You're right. This ain't possible. Ankhain khol kay dekha hota to mass balance nazar a jata.

 

[Faizan Muhammmad]

if the case were to be live, there would be current flowing through the metal container.
But there will be a fuse --> Not always

look at the plug
it is a three pin shoe
sort of the one with built in fuse

 

[funky brat]

look at the plug
it is a three pin shoe
sort of the one with built in fuse

Yeah.

 

[Faizan Muhammmad]

Yeah.

ATP main 24/30 bhee ajain to baree baat hotee hai
people have gotten Bs in this and yet A* in total

 

[funky brat]

ATP main puray marks bhi a sakty hain, Paper 1 and 2 kay liye margin rakhna chahye.

 

[Faizan Muhammmad]

ATP main puray marks bhi a sakty hain, Paper 1 and 2 kay liye margin rakhna chahye.

true in many ways it is the easiest but the element of surprise.....

 

[funky brat]

true in many ways it is the easiest but the element of surprise.....

I hope it's really easy this time.
​

 

[Mahnoorfatima]

Does a heart patient needs plant saturated or animal saturated fat? I guess plant but why?

 

[Faizan Muhammmad]

Does a heart patient needs plant saturated or animal saturated fat? I guess plant but why?

plant fats are usually unsaturated and animal fats are usually saturated
Animal fats have cholestrol, plants dont

 

[DaniyalK]

Can someone explain this?

 

[FLRNAB]

Do you know what is meant by
'the case is live'. It means that if you touch it, you will get an electric shock
Also how can an electric kettle not have a fuse?

I didn't see the 3 pin shoe.

look at the plug
it is a three pin shoe
sort of the one with built in fuse

Thanks for pointing that out. Missed my eye.

So you think it can be correct?

Only in case of 2 pin shoe.
But also in the cases the examiner would not consider like if it was china maal. Shape is same but no fuse in the shoe.

Can someone explain this?

You can easily work this out by simple elimination:

a) Boiling point - you know that ethene is a gas, and that polyethene is a solid (e.g. polythene bags) so there MUST have been a change in boiling point! So it's not (a).

b) Again, you know that ethene is a gas, and that polyethene is a solid, and solids have greater densities than gasses, so again, its not (b).

d) Molecular formula must have changed, because you have formed a polymer - you have linked together lots of ethene molecules, therefore the molecular formula (if not the empirical formula) must have changed, so its not (d).

So yes, its (c) as total mass is concerved in chemical reactions. (Which is why you always need to balance chemical equations).

[Copied]

 

[***amd***]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s12_qp_22.pdf
Q2 b

 

[exploded diper]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s12_qp_22.pdf
Q2 b

Cereal d has more fibre which helps releave constipation since it helps in peristalisis

 

[***amd***]

7.The leaf will be able to photosynthesise despite it being cutoff.So in daylight it will use up CO2 and conc will be lower than normal.At night cells inside will respire and there will be no photosynthesis so there is net loss of CO2 and conc increases.So color changes from purple to yellow

17.Viruses are not cellular and they mostly have RNA instead of DNA so i guess it would be B.

31.This sort of question is mostly a tukka but it could make sense that it lays in water that is very vulnerable to outside forces like man,wind or other weather conditions which could lead to eggs not being able to grow.So it would be B.

7. but why would the leaf not respire maintaining CO2 concentration as normal?
17. it says "made of cells", that means it is not unicellular, it must be multicellular. so, shouldnt it be fungus?
31. why not C?

 

[hussey96]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s13_qp_12.pdf
Q.)14. please help

 

[***amd***]

Cereal d has more fibre which helps releave constipation since it helps in peristalisis

fibers help relieving constipation? i thought it contributed to constipation.

 

[FLRNAB]

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Physics (5054)/5054_s13_qp_12.pdf
Q.)14. please help

Total Mass of lorry while going up is it's own mass and the mass of sand which is 10000 + 5000 = 15000kg
Lorry goes up with sand so it gains P.E p1 (mass 15000 kg).
Lorry dumps the sand so loses 5000 kg and returns to the bottom so it has lost P.E p2 of it's own mass (10000 kg).
So P.E gain is p1 - p2
Maths:
(15000 * 50 * 10) - (10000 * 50 * 10) = 2500000 J