Error in Measurements (Leaving Cert Physics): Flashcards

Systematic errors and random errors

Error consistently affecting measurements in same direction (always higher or always lower than true value)

Predictable and consistent

Reading scale from wrong angle, not perpendicular to it

Uncalibrated instrument (balance not zeroed)

Systematic error (consistently lower results)

Calibrate instruments, correct technique, proper viewing angle

Unpredictable variation when repeating measurements

Around the true value

Take multiple measurements and calculate average

How close measured value is to true value

How close repeated measurements are to each other

$\frac{\text{error}}{\text{true value}} \times 100\%$

$\frac{\text{estimated error}}{\text{measured value}} \times 100\%$

Half the smallest division of measuring instrument