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Measurement + Errors
Question | Answer |
---|---|
What are the seven base quantities and their units | -Distance(metre) -Time(second) -Mass(kilogram) -Current(Ampere) -Temperature(Kelvin) -Light intensity(Candela) Amount of substance(mole) |
What are the multipliers for: femto, pico and nano | -Femto=10^-15 -Pico=10^-12 -Nano=10^-9 |
What are the multipliers for: micro, milli and centi | -Micro=10^-6 -Milli=10^-3 -Centi=10^-2 |
What are the multipliers for: Deci, kilo and mega | -Deci=10^1 -Kilo=10^3 -Mega=10^6 |
What are the multipliers for: giga and tera | -Giga=10^9 -Tera=10^12 |
What are the two types of error | Systematic and Random |
Define precision | No of DP |
Define accuracy | How close your results are to the true value |
Define resolution | Is my sample good enough to see what I need to see |
How do you calculate instrumental uncertainty | 1/2 of the smallest division on the instrument |
What must the I.U be less than for an instrument to be considered suitable | 5% |
What is the I.U for a ruler | 5x10^-4m |
How do we calculate experimental uncertainty | 1/2 the range of the results |
How do we calculate absolute uncertainty | Take the worst of the I.U and E.U and express as a percentage |
What is the equation for RMS | Root of ∑(x-mean x)/n |
When can RMS be used | If it is a Gaussian distribution |
Define error | The difference between the measured result and the true value |
Define uncertainty | the interval/range in which the true value could be considered to lie |
What is the I.U for vernier calipers | 5x10^-5 |
What is the I.U for screw gate micrometers | 5x10^-6 |