2 - Practical Skills Flashcards
What is an error?
Difference between measured/calculated result and the true value or its range
What is precision?
Consistency between measured/calculated values, they should cluster together if precise.
What is accuracy?
How close or equal to true value
What types of errors can precision be affected by?
Only random
What types of errors can accuracy be affected by?
Random and systematic.
What is a systematic error?
When every result is shifted by the same value each time, it is usually concerned with equipment set-up.
How can limit systematic errors?
Can be minimised by checking for zero error (equipment calibration) and avoiding parallax errors.
What is a random error?
Unpredictable error due to the person measuring/calculating.
How can we minimise random error?
Taking averages of repeats or drawing a line of best fit (as then values will cancel out and reach a sort of common ground)
What is a parallax error?
An error due to the shift of objects position as it is viewed from different angles.
What can we do to make sure parallax error is limited?
Looking bird eye view.
What is the absolute uncertainty?
The total uncertainty of value.
What is a percentage uncertainty?
The uncertainty as a percentage.
How can we reduce the percentage uncertainty?
Measuring larger values as the the percentage decreases.
How can a graph present a systematic error?
The line of best doesn’t go through the origin, meaning values plotted are shifted.
