Prefixes & Uncertainties Flashcards
What prefix is used to represent x10 to the power +3 ?
kilo (k)
What prefix is used to represent x10 to the power +6 ?
Mega (M)
What prefix is used to represent x10 to the power +9 ?
Giga (G)
What prefix is used to represent x10 to the power +12 ?
Tera (T)
What prefix is used to represent x10 to the power +15 ?
Peta (P)
What prefix is used to represent x10 to the power -3 ?
Milli (m)
What prefix is used to represent x10 to the power -6 ?
Micro (μ)
What prefix is used to represent x10 to the power -9 ?
Nano (n)
What prefix is used to represent x10 to the power -12 ?
Pico (p)
What prefix is used to represent x10 to the power -15 ?
Femto (f)
What is meant by a “Percentage” uncertainty in a value?
The uncertainty in a value is given in the form of a percentage. For example : 4ms⁻¹ ± 7.5%
What is meant by an “absolute” uncertainty in a value?
The uncertainty in a value is given in the same units as the value. For example : 4 ± 0.3 ms⁻¹
What is meant by a “Random” uncertainty?
Small variations for each result, giving a range of results for each variable measurement. Can be reduced by the calculation of an average value and further calculation.
What is meant by a “Systematic” uncertainty?
All measurements affected in same way, all are either too large or too small. If the magnitude of the Error can be found, results data can be corrected accordingly.
What is meant by a “Reading” uncertainty?
Scales on measuring equipment can only show to a certain minimum accuracy. Comes in two distinct forms; Analogue and Digital.
What is meant by a “Calibration” uncertainty?
The difference between the actual value of a quantity and the value indicated by the measuring instrument. Calibration errors occur because no measuring instrument is perfect.
How is the overall uncertainty in a calculated value found?
The perecentage uncertainty in each variable is found, then whichever is the largest uncertainty is identified and that value is applied to the calculated value.
What is the uncertainty in an “analogue” reading?
± half of the smallest unit.
What is the uncertainty in a “digital” reading?
± one of the smallest unit.
