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 student measures the time period of $100$ oscillations of a simple pendulum four times. The data set is  $90\;s$ ,$91\;s $, $95\;s$ and $92\;s$. If the minimum division in the  measuring clock is $1\;s$, then the reported mean time should be

Measure of two quantities along with the precision of respective measuring instrument  $A = 2.5\,m{s^{ - 1}} \pm 0.5\,m{s^{ - 1}}$, $B = 0.10\,s \pm 0.01\,s$ The value of $AB$ will be

The maximum error in the measurement of resistance, current and time for which current flows in an electrical circuit are $1 \%, 2 \%$ and $3 \%$ respectively. The maximum percentage error in the detection of the dissipated heat will be

The following observations were taken for determining surface tension $T$ of water by capillary method:

diameter of capillary, $D= 1.25 \times 10^{-2}\; m$

rise of water, $h=1.45 \times 10^{-2}\; m $ 

Using $g= 9.80 \;m/s^2$ and the simplified relation $T = \frac{{rhg}}{2}\times 10^3 N/m$ , the possible error in surface tension is ........... $\%$

In the density measurement of a cube, the mass and edge length are measured as $(10.00 \pm 0.10)\,\,kg\,$ and $(0.10 \pm 0.01)\,\,m\,$ respectively. The error in the measurement of density is