Errors And Uncertainties
Which statement correctly describes a systematic error?
Which method most effectively reduces the effect of random errors in an experiment?
A balance reads 0.20 g when nothing is placed on the pan. A student then measures an object as 15.40 g. What is the corrected mass?
A thermometer consistently reads 2 °C above the true temperature. Which action will remove this error?
Which pair of statements correctly distinguishes accuracy from precision?
Four darts land tightly clustered together but far from the bullseye. Which description best fits this result?
Two lengths are measured as A = 12.0 ± 0.2 cm and B = 5.0 ± 0.1 cm. What is the absolute uncertainty in (A − B)?
A quantity is calculated from Z = A × B. A has a percentage uncertainty of 3% and B has a percentage uncertainty of 2%. What is the percentage uncertainty in Z?
The radius r of a sphere has a percentage uncertainty of 2%. The volume is given by V = (4/3)πr³. What is the percentage uncertainty in the volume?
A current is measured as 2.50 ± 0.05 A. What is the percentage uncertainty?
A digital balance displays a mass as 24.567 g. What is the absolute uncertainty in this reading?
Five repeated readings of a time interval are 4.2, 4.5, 4.3, 4.6 and 4.4 s. Taking the uncertainty as half the range, what is the absolute uncertainty?
A calculated resistance is 47.3 Ω with a calculated uncertainty of 2.8 Ω. How should the result be correctly quoted?
A student determines the density of a cylinder from ρ = 4m/(πd²L). Which measured quantity should be measured most carefully to reduce the uncertainty in ρ most effectively?
A speed is found from v = distance/time, where distance = 100.0 ± 0.5 m and time = 20.0 ± 0.2 s. What is the percentage uncertainty in the speed?
A scientist weighs a sample five times on a balance that still reads 0.3 g with the pan empty. The five readings are very close to one another. Which statement about these readings is correct?
The percentage uncertainty in a measured power P is 4%, and P = 250 W. What is the absolute uncertainty in P?
Which of the following is a source of random error rather than systematic error?