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Edexcel Unit 6b (6PH08) PRACTICALS

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park:
thanks tq

student:
Sorry, but I got confused here..
Bold text inside the quote was written by me.

--- Quote from: T.Q on May 16, 2010, 03:31:26 pm ---...

eg. A voltmeter might read: 1.25v +/-0.01v. (I guess here is a mistake, because the rest assumes it's +/-0.1v) This implies voltage between 1.24 and 1.26

Actual uncertainty therefore would be:
1mm for the rule
0.1 for the voltmeter (not 0.01?)
0.01mm for the micrometer
This can also be written as % uncertainty using the following formula:

...

Examples:
1. Finding R using a voltmeter and an ammeter if the reading on the voltmeter is 2.45v and the ammeter is 0.96A:

V=2.54 +/-0.01v
% error = 0.01/2.54*100 = 4% (not 0.3937...~0.4?)

I= 0.96A +/-A
0.01/0.96*100= 1%

combined error: 4% (0.4%)+1%= 5% (1.4% ~1%)

r=v/i

2.54/0.96 =2.56 +/- 5% (not 5%) ohms

--- End quote ---

Thanks for notes by the way! ;)

T.Q:
added *Physics Guidance notes on experimental work edexcel new spec AS/A2*

check first post

angelofhope:
Thanks  for those notes T.Q.. m sure that wud very helpfull for those of us who are doing dat paper  :D

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