Practical Skills Flashcards
What is accuracy?
How close your result is to the given result
What is precision?
How close your result is to repeated tests
What are errors?
The difference between an individual result and the true value
What is an uncertainty?
An estimate of the range of values within which the true value lies for a measurement.
What is the absolute uncertainty when measuring something with a ruler?
+/- half the intervals
OR
+/- the interval of measured from top and bottom
Percentage uncertainty=
(Absolute uncertainty)/(measured value) x 100
Having found multiple measurement for the length, what is your estimated value and what if your absolute uncertainty?
The estimate value is the mean of the results.
The uncertainty is +/- half the range
If you have drawn a graph with a line of best fit and a worst acceptable line of best fit, what is the equations for the % uncertainty of the gradient?
((Grad if lobf - Grad of walobf)/(Grad of lobf)) x 100
What if percentage difference? And what is its general equation?
The percentage difference between an experimental value and the accepted value.
=(((my result)-(true value)) / (true value)) x100
Define independent variable
Something you decide to change
Define dependent variable
The effected variable that you measure (and the result depend on)
Define control variables
Things you keep the same to have a fair test
When using a micrometer there is an inner ring and an outer ring. What does the inner ring go up in and what does the outer ring go up in
Inner ring: half a millimetre
Outer ring: 0.1mm
