Time intervals measured by a clock give the following readings: $1.25 \; s, 1.24 \; s, 1.27 \; s, 1.21 \; s$,and $1.28 \; s$. What is the percentage relative error of the observations?

$A$ certain body weighs $22.42 \; g$ and has a measured volume of $4.7 \; cc$. The possible errors in the measurement of mass and volume are $0.01 \; g$ and $0.1 \; cc$,respectively. Then the maximum percentage error in the density will be: (in $\%$)

Four persons measure the length of a rod as $20.00 \ cm$,$19.75 \ cm$,$17.01 \ cm$,and $18.25 \ cm$. The relative error in the measurement of the average length of the rod is:

The errors in the measurement which arise due to unpredictable fluctuations in temperature and voltage supply are:

Measurement of two quantities along with the error is: $A = 2.5 \ ms^{-1} \pm 0.5 \ ms^{-1}$,$B = 0.10 \ s \pm 0.01 \ s$. The value of $AB$ will be:

Two students $P$ and $Q$ perform an experiment to verify Ohm's law for a conductor with resistance $R$. They use a current source and a voltmeter with least counts of $0.1 \, mA$ and $0.1 \, mV$,respectively. The plots of the variation of voltage drop $V$ across $R$ with current $I$ for both are shown below. Which statement is most likely to be correct?