5. Formula and amounts (UNCERTAINTY + ERRORS)

Question 1

What is uncertainty

Answer 1

The maximum error you could have on a measurement

Question 2

symbol for uncertainty

Answer 2

±

Question 3

What is the uncertainty for an apparatus

Answer 3

The uncertainty for an apparatus is half the smallest increment it can measure
eg: a burette measures to the nearest 0.1 cm3 so 0.1 divided by 2 is 0.05cm3

Question 4

Give the equation to calculate percentage uncertainty

Answer 4

percentage uncertainty = uncertainty / reading
x100

Question 5

When do you times the uncertainty by 2 when calculating % uncertainty

Answer 5

When 2 measurements are taken on the apparatus eg: burette, balance

Question 6

Give 2 ways to minimise percentage uncertainty

Answer 6

• increase resolution of apparatus
• increase size of measurement