Practical Skills (Measurements and Errors) Flashcards
What are the SI prefixes and their values (above x10^1)?
- kilo, k, x10^3
- mega, M, x10^6
- giga, G, x10^9
- tera, T, x10^12
What are the SI prefixes and their values (below x10^1)?
- centi, c, x10^-2
- milli, m, x10^-3
- micro, μ, x10^-6
- nano, n, x10^-9
- pico, p, x10^-12
- femto, f, x10^-15
What are the six base units you need to know, and their associated SI units?
- mass (kilogram, kg)
- length (metres, m)
- time (seconds, s)
- amount of substance (mol, mol)
- temperature (kelvin, K)
- electric current (amps, A)
Define error
the difference between the individual result and the true value
Define random error
an error introduced by variable which you cannot control
Define systematic error
an error that can be introduced by the experimental apparatus or method
(cause each value to be consistently too big or too small)
Define precision
a measure of how close repeated results are to one another
Define accurate
how close a result is to the true value
Define a repeatable result
a result is repeatable if you can repeat an experiment multiple times and get the same result
Define a reproducible result
a result is reproducible if someone else can reproduce your experiment using different equipment or methods and get the same result
Define resolution
the smallest change in what’s being measured that can be detected by the equipment
Define uncertainty
an estimate of the range of values within which the true value lies for a measurement
Define absolute uncertainty
the uncertainty of a measurement given as a fixed quantity
Define fractional uncertainty
the uncertainty given as a fraction of the measurement taken
Define percentage uncertainty
the uncertainty given as a percentage of the measurement taken
