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%uncertainty PHYSICS 33

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in all the papers they ask about it , how am i suppose to find it? i know the equation :value of uncertainty/actual value X 100% . But have problems with finding the uncertainty value, can some1 help me ?
 
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i am not completely sure about this but just trying to help :p

lets suppose you are measuring the length using a meter rule... then the uncertainty in it will be +-1... so you will divide 1 by actual length and multiply by 100.... e.g 1/35 *100.......where 35 is actual length that we have measured ...

if still not sure go here viewtopic.php?f=26&p=72566#p72566
 
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basically u just use the smallest division of the device.
say if you are using a venier callipers to the get value, then the smallest division is 0.01cm
percentage uncertainty = 0.01/ (your value measured ) x 100%

thats it.
so smallest division for micrometer screw gauge = 0.01mm
stopwatch = 0.1s
angle = 1'
meter rule = 0.01cm = 0.0001m
 
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Er... Corrections:

value of uncertainty = value of smallest division / 2

smallest division for meter rule is 0.1cm or 1mm or 0.001m (whichever way you like it),

0.01cm is for vernier calipers
 
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so uncertainity value for metre rule is 0.5 mm..

what do we write for justify the no. of sig. figs. question??
 
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