Paper 3 Stuff

Question 1

What is Absolute Uncertainty​ ?

Answer 1

uncertainty given as a fixed quantity e.g. 7 ± 0.6 V

Question 2

What is fractional uncertainty ?

Answer 2

uncertainty as a fraction of the measurement e.g. 7 ± 3/35 V

Question 3

What is percentage uncertainty ?

Answer 3

uncertainty as a percentage of the measurement e.g. 7 ± 8.6% V

Question 4

What is the uncertainty in a reading ?

Answer 4

The ​uncertainty in a reading​ is ​ ​± half the smallest division​,
e.g. for a thermometer the smallest division is 1°C so the uncertainty is ±0.5°C

Question 5

What is the uncertainty in a measurement ?

Answer 5

The ​uncertainty in a measurement​ is ​at least ±1 smallest division,
e.g. a ruler, must include both the uncertainty for the start and end value, as each
end has ±0.5mm, they are added so the uncertainty in the measurement is ±1mm Digital readings and given values will either have the uncertainty quoted or assumed to be ​± the last significant digit​ e.g. 3.2 ± 0.1 V, the ​resolution​ ​of an instrument affects its uncertainty

Question 6

How do you work out the uncertainty for repeated data

Answer 6

For repeated data the uncertainty is ​half the range​ (largest - smallest value), show as mean ± range