Measurements Flashcards
random uncertainties occur due to… which causes
The experimenter being unable to repeat his precisely which causes a scatter of readings about a mean value
Systematic uncertainties occur due to
Faulty equipment and or consistently poor experimental technique(ie. Parallax error…)
Random uncertainties have an equal chance of being
Negative or positive ie higher or lower than the mean that’s why we use plus or minus
The magnitude of the random uncertainty in a set of readings determines
The precision of the experiment
Precision is random
The magnitude of the systematic uncertainty in a set of readings determines
The accuracy of the experiment
Systems are accurate
A precise set of readings has a small
Random uncertainty
An accurate set of readings has a small
Systematic uncertainty
Random certainties can be reduced but not
Completely eliminated
Random uncertainties can be reduced by
Taking repeated measurements and finding an average value
Systematic uncertainties due to faulty equipment can be reduced and eliminated by
Recalibrating the instruments using standard instruments
Systematic uncertainties due poor experimental techniques can be reduced and eliminated by
Better experimental techniques such as eliminating parallax error by taking readings at eye level
An obtained reading is recorded with
Its uncertainty
The reading and the absolute uncertainty must have
The same number or order of decimal places
When two or more readings are combined either by addition or subtraction, the absolute uncertainties are
Always added
When quantities are multiplied or divided, their
Fractional or percentage uncertainties are added. So the resultant uncertainty is divided resultant readings which is the same as adding the two fractional or % uncertainties
