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Physics paper 31 , (a death call)

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What about the one that said give an example of a change of state when thermal blablabla. The second part: what is the effect on blaa? What did u write?
 
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no
you had the current in one branch
you had the voltage which was same in both branches
current in one branch is not related to other
u had to find the current by V/R
so current in 2nd branch was 3A
the total resistance across parallel was 1.2 ohm
effective Resistance of circuit was 6/3.8=1.579 ohm
so u take the parallel's resistance out to get the other resistance 1.579-1.2= 0.379 ohm
I DID IT SO but idk why every one said it's wrong !!!!
 
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Lol i'm not tooo worried. I mean I know I did good.
I'm sorry bout your papers though :(

Are you so desperate to make yourself believe that you didn't lose those 5 marks that you will start insulting me?
You're right about glass being a bad conductor of heat but that actually makes my answer correct.
Since glass is a bad conductor of heat it takes time for the heat to get to the liquid
This is quoted from a website:
"
A flask made of thick glass is filled with a coloured liquid Acork is fitted through which a narrow glass tube is inserted. There is a scale marked onthe tube. Some liquid will rise up inside the tube up to a point which is marked by O onthe scale. Now the flask is placed inside a big vessel of boiling water which heats up theflask and as well as the liquid inside. It is observed that the liquid inside the tube firstcomes down to a position marked by A and later it rises again, goes past O and reaches ata point marked by B. The reason is that there is an expansion of the glass container at the beginning. As the glass is a bad conductor of heat, it takes some time for heat to reach theliquid inside the flask and because of this there is no expansion of liquid at the initialstage. Thus the liquid surface comes down from O to A inside the tube. After a while theheat starts flowing into the liquid for which the liquid expands and it begins to rise insidethe tube. The expansion of liquid is more than the expansion of glass. Thus we see thefinal rise of liquid is at B above the point O"
Enough said.
Edit: Font colour of website was black, changed it.
bro they were only 2 marks because 2 marks for one for expansion and 2 marks for one for the expansion of water and one mark for why one is bigger than the other and until now u didnt convince me why evaporation is wrong and ur answer is the only right answer. and i will keep telling u that solid expansion is never that noticeable and i will only move by a few mm if that was true and so it cant be seen by the one doing the experiment.
 
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temperature will decrease ice (o degree celsius)...it is exothermic
i guess u can understand the question in different ways, maybe u understood after the experiment and i understood during the experiment, i dont know which is correct though
 
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i guess u can understand the question in different ways, maybe u understood after the experiment and i understood during the experiment, i dont know which is correct though
but I wrote change in state is freezing...u thnk is correct same as liquid to solid ryt...they will accept???
 
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bro they were only 2 marks because 2 marks for one for expansion and 2 marks for one for the expansion of water and one mark for why one is bigger than the other and until now u didnt convince me why evaporation is wrong and ur answer is the only right answer. and i will keep telling u that solid expansion is never that noticeable and i will only move by a few mm if that was true and it cant be seen by the one doing the experiment.
evaporation is wrong why?
because evaporation wont leave a much net difference
the area of tube is very small
his answer is right

water has a high heat capacity so it will resist the change in temp
more over glass is a bad conductor of heat
so initially the apparatus will expand so level drops
when water is finally transferred heat, it expands, kinetic energy increases and level rises
liquids expand more than solid was answer for the last part

the area exposed is too small for a net large evaporation
 
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evaporation is wrong why?
because evaporation wont leave a much net difference
the area of tube is very small
his answer is right

water has a high heat capacity so it will resist the change in temp
more over glass is a bad conductor of heat
so initially the apparatus will expand so level drops
when water is finally transferred heat, it expands, kinetic energy increases and level rises
liquids expand more than solid was answer for the last part

the area exposed is too small for a net large evaporation
he didnt say that the difference was big :p and he didnt say for how long did he leave the experiment and so there might be enough time for lots of evaporation to happen :p
 
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yea and also the difference in surface area is what made one to become higher than the other
 
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