Significant Figures

[diwash]

Hello everyone,
I am confused with the use of significant figure in Physics and Chemistry paper 2 and paper4. Can any one explain me about it..
And should the answer be in the same significant figure as in the marking scheme. I think one hardly gets the answer in the same significant figure that is marked in the marking scheme.

 

[hassam]

as far as i know the A mark (answer mark) will be awarded only if ur answer matches ms anser

 

[diwash]

OK.....then how can we write to the same significant figure as in the marking scheme?...I was really asking that.

 

[hassam]

there are some rules to follow read the attached file.....

 

[MAVtKnmJ]

The thumb of the rule here is that in Chemistry you have to look at the Decimal Places and in Physics you have to look at the Significant Figures. Now in both cases your answer should be given according to the accuracy of the instrument used for the measurements, otherwise according to the data given to you in the question by the examiner.

 

[DragonCub]

I was told that the standard requirement of the accuracy to which we round numbers is for most values to 3 s.f. It ought to be generally accepted in all subjects' calculations (mechanics, statistics, physics, chemistry, etc.)
There may be some exceptions such as 1 d.p. for angle size (in degrees, still 3 s.f. in radians)
And when the question assigns particularly about that, e.g. Iteration to 2 d.p, then just do what the question asks.
Also it should be appropriate to use the EXACT value for further calculation although the current result may need rounding.

(Just as I heard, whether it's true I am not sure. Yet I think that does help reduce risk in accuracy.)