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Physics P5 in 5 minutes !!!

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Ok but if i do write the reason then will i get negative marks for it and if i draw the water bath in the diagram will they deduct a mark for it or ignore it?
There no negative mark for writing some wrong in CIE Alevel
 
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im a lady :eek: thanks a lot ,,,,

Q 2 part b,,,,first calculate 1/h then find uncertainity in h by the formula (DELTA)h/ h nd multiply this uncertainity with 1/h that u got b4....
eg for 400 +/- 5.....1/h will be inverse of 400 x 10 ^ -3 which is 2.5....now for the uncertainity calculate fractional error...5/400 (notice that 10^-3 in the denominator and numerator cancels out so u dont need to put it in calculation) =0.0125....now multiply this with ure final ans of h inverse i.e : 2.5 x 0.0125 =0.03125,,,,,there u go...uncertainity will be upto 1 s.f and the value will be to the same no# of d.p...therefore answer is 2.50 +/- 0.03


i really hope i havent made it very complicated :)

does it cancel out in every question or this one is specific? :/
 
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does it cancel out in every question or this one is specific? :/
cancels out in every since the error and the value are both raised to the same power...ONLY if they both are raised to the same power
and for drawing in error bars

when u have found out the error like 0.5 +/- 0.2 then u plot 0.5 first and a line joining it to the point 0.2 units ABOVE 0.5 and 0.2 units BELOW 0.5, so u join three points 0.5, 0.7 and 0.3 with ure encircled point at 0.5
 

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how will we know if its cancelled out or no?
try M/J/12/52 i dont think we have to camcel out here.

cancels out in every since the error and the value are both raised to the same power...ONLY if they both are raised to the same power
and for drawing in error bars

when u have found out the error like 0.5 +/- 0.2 then u plot 0.5 first and a line joining it to the point 0.2 units ABOVE 0.5 and 0.2 units BELOW 0.5, so u join three points 0.5, 0.7 and 0.3 with ure encircled point at 0.5
 
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how will we know if its cancelled out or no?
try M/J/12/52 i dont think we have to camcel out here.
it does guaranteed, cuz the table heading says 10^-2 and that goes for both the value and the error since they r in the same coloumn
 
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It depends on the examiner and it is better to state the constant in the paragraph although the examiner might credit the diagram.Why take a chance.
i didnt quite understand what u said about why take a chance. If a constant variable im writing if i draw it in the diagram as to how to control it, it will be better for me or not? or should i write it in the paragraph only. if i draw in the diagram i wont lose marks even if its wrong?
 
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i didnt quite understand what u said about why take a chance. If a constant variable im writing if i draw it in the diagram as to how to control it, it will be better for me or not? or should i write it in the paragraph only. if i draw in the diagram i wont lose marks even if its wrong?
I thought that u meant that u draw the instrument in the diagram and and forget to mention it in the paragraph so sorry about that.
Now about your question I think it is not given credit most of the time(although credit is give for stating current is constant instrument) .u can write it and I dont think any marks will be deducted for writing a wrong answer bcoz there is no negative marking and in most situation the instrument for keep variable constant is not required by marking scheme there will be no marks deduction nor u will get a marks for it because it is not demanded by examiner but u never know if get credited for it.So writing a correct one never hurts but avoid writing a wrong one
 
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no i meant q2 (a) that 1 mark gradient from the equation

This is for the October - November 2010 p52 question, 2(a):

If you mean the first part where you have to find out the gradient of the line of lgT on the y - axis and lgL on the x - axis, the gradient is b because taking log on both sides, we get

lgT = lgA + b * lgL

If lgT = y and lgL = x, then we have

y = lgA + bx

So gradient is equal to b.

Good Luck for all your exams!
 
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