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    (Original post by Davror)
    And thats what I thought... but! The ball was neutral rite? This means it has Positive and Negative charges.

    The rod was negatively charged. I think the electrons moved to the right of the ball, making the rod, and positive charges attract (now on the left of the ball attract). Therefore surely the ball moves towards the rod? Maybe im wrong - but Page 6, part 4 of the CPG Physics revision guide suggests the same thing.

    Lemme no what you think to this everyone...
    I thought the ball was negatively charged because I thought it would still be negative immediately after the positive rod had been removed...but then I also thought that the ball was neutral as it would uncharge, then attracted by the negative rod...but then I also thought, if the rod was replaced quickly then there wouldn't have been time for the ball to uncharge...I had no idea!
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    Davror, you think it was right? I did the P=IV calculations, Im sure it is right
    I jsut used that for accuracy, but maybe we used wrong calculation??
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    Generally I think it was a bad question. You could interpretate the wording and the meaning in so many different ways. Lets not worry about this after all hey? Its worth 3 marks for this little picky bit. Whats done is done... Theres still another 97% up for grabs out there somewhere... Besides it was the last question! Its not meant to be easy!

    Davror
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    (Original post by SketchyCanvas)
    For my transformer answer i got: 2070, 20 and 180? It said whats the current on the SECONDARY COIL and since its a step up transformer the secondary coil current much be bigger than the primary.
    I thought that if it was a step up transformer the secondary voltage would be higher than the primary? At least motors/generators didn't come up.
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    (Original post by xxjayx)
    Davror, you think it was right? I did the P=IV calculations, Im sure it is right
    I jsut used that for accuracy, but maybe we used wrong calculation??
    Yea I have a recollection of getting that number. I think how it works is that providing you've wrote down the formula and shown some sort of method - We should get the majority of the marks anyway even if we are slightly wrong. But I dont think accuracy can be a bad thing.
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    Hmm.. at least theres marks for method lol Yeh im glad motors/generators didnt come up! wooo!!! lol
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    Yeah exactly - I'm counting on those method marks here!
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    wot did u guys get bout the Word questions - not calcualtions of the transformer question like wot were the 2 transformers?

    I put first one step up - second one step down
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    The one with the cottage?
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    first - step up transformer to raise voltage and lower current so heat energy would not be lost.

    seond- step down transformer, to lower voltage and to put the voltage back to what the housing electrics can take
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    but didn't it already have a transformer in the beginning? There was a step down transformer then transformer 1 then transformer 2 then the cottage.
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    nope jay is right - thats wot i put
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    anyone have a clue wot the grade boundaries will be? last year an A was 55% i think maybe a bit more this time - i reckon i got 70 - that shud b high A
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    no, it was basically asking, what happens to electricity from power station to the home, and my theory is right, I didnt pay TOO much attention to the picture, but I saw 2 transformers, so gathered one was stepup (from power station) and one was step down (to houses)
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    Isn't physics grade boundary usually quite low?

    I'm worried about the biology grade boundaries...those annoying questions that I had to make up!
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    Its Biology that Im worried about - I no this is the wrong thread but what do you think the A/A* boundaries will be for bio?
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    At a guess I would say A is around 58%
    I would say I got around 50%
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    yea triple physics will b hard the extension
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    Biology, I think the A boundary will be 64% ish and A* 70
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    I just assumed that Transformer 1 would be the first one and Transformer 2 the second - I didn't look at the picture much either.

    Yeah I put that transformer 1 increases the voltage so that energy transfer is more efficient, and transformer 2 acts as a step down transformer to decrease the voltage back to 230V to be transferred to the cottage.
 
 
 
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