M2 - Error

Question 1

error

Answer 1

the difference between the measured value and the ‘true value’ of a measurement. 2 types

Question 2

Random errors:

Answer 2

the measured value differs in magnitude or direction from the true value
randomly (inconsistently).

○ Occurs as a result of variations in measurement technique - sometimes referred to as operator errors

○ Often affects the reliability of measurements.

○ Caused by unpredictable changes in the experiment → to the instruments or
environmental conditions

○ E.g. change in temperature, air.

○ Can be reduced by repetition and taking the average of the final result.

Question 3

systematic errors

Answer 3

• the measured values differ in magnitude or direction consistently.

○ Caused by poor measuring technique/equipment limitations. E.g. poorly calibrated equipment

○ Affects the accuracy of measurements.

○ Occurs to the same extent in each measurement → often in the same direction (above or below true value)

○ Can be reduced by checking instruments against a standard before use (calibration), following the correct instructions for equipment use

○ 3 types: calibration, parallax, limit of reading.