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Physics P3 (Practical) Notes and Tips

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My scale requires a bit of calculation, 1 small box is 0.04 units so counting without calculation is kind of risky. As for the mark schemes, all the recent ones give only one example of (3,10) as an awkward scale and that's it. My teachers in school marked my scale right but I have a niggling feeling that they don't adhere strictly to the mark schemes when they grade our work.
Anyway, thank you for help,it's hard to get such comprehensive replies!:)
Its a habit now :p Takes away a lot of time in papers like Biology from me.
Do you guys draw curves with flexi curve ruler or with a free hand?
Free hand. If you have a flexi curve it would obviously be much better. I don't think we can get those here.
 
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Its a habit now :p Takes away a lot of time in papers like Biology from me.

Free hand. If you have a flexi curve it would obviously be much better. I don't think we can get those here.

Any thing we need to be careful of when using free hand? How particular are they with the way curve is drawn? Thanks again :)
 
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Use the Formula :-
K=Constant..!
Now use %Diff=K1-K2/K(avg) * 100

If u Percentage Diff. Lies within 10%. i.e <10%. So ur results supports the The suggested relationship!
Or you could calculate the percentage uncertainty.

Let's say we take F=kx
∆K/K = ∆F/F + ∆x/x
thus % uncertainty in k = ∆K/K x 100
If your percentage difference > %uncertainty, the relationship shown is not valid
If your percentage difference < %uncertainty, the relationship shown is valid


Both methods work, trust me.
 
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can any one tell me it is preferable to take reading of length in m or cm which is more preferable?
and Ammeter show reading in mA can u convert it to A?
 
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can any one tell me it is preferable to take reading of length in m or cm which is more preferable?
and Ammeter show reading in mA can u convert it to A?
Depends on what is asked. In some questions, they say:
X= _________ cm
In that case, centimetres. Nothing else.
If a unit is not mentioned, give your readings based on what apparatus you are using to measure the thing.
Eg. Metre Ruler - cm
Vernier Calipers - cm
Micrometer screw gauge - mm

Please do check what unit they are asking for before answering...
 
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i
How do we find Percentage uncertainty? It is asked in every Practical Paper in Question 2.
it is measured by formula = absolute error/measured value x 100

absolute error of : metre rule (in theory)=1mm
metre rule(when measuring moving object)= 2mm to 10mm
vernier calliper=0.1mm
micrometer = 0.01mm
stopwatch (in theory)=0.1s
stop watch(in practical) = 0.1-0.5s
 
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absolute error of newton metre is 0.1N but in practical it is 0.2 to 1.0N

Note: Absolute error in practical is always greater than theoratical absolute error
So I'm not suppose to use theoratical Value, right? I can use any Value between 0.2-1.0 :)
Thanks.
Any other than this I'm suppose to know? I'm really bad in physics :/
I mean Voltmeter, Ammeter, etc..
 
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