The length of a rod is $(11.05 \pm 0.05) \ cm$. What is the length of two such rods?

The least count of a stop watch is $\frac{1}{5} \text{ s}$. The time of $20$ oscillations of a pendulum is measured to be $25 \text{ s}$. The maximum percentage error in the measurement of time will be .......... $\%$

The initial and final temperatures of water as recorded by an observer are $(38.6 \pm 0.2)^{\circ}C$ and $(82.3 \pm 0.3)^{\circ}C$. The rise in temperature with proper error limits is

The random error in the arithmetic mean of $100$ observations is $x$; then the random error in the arithmetic mean of $400$ observations would be

We measure the period of oscillation of a simple pendulum. In successive measurements,the readings turn out to be $2.63 \;s, 2.56 \;s, 2.42 \;s, 2.71 \;s$,and $2.80 \;s$. Calculate the absolute errors,relative error,and percentage error.

The pressure on a circular plate is measured by measuring the force on the plate and the radius of the plate. If the errors in measurement of the force and the radius are $5 \%$ and $3 \%$ respectively,the percentage of error in the measurement of pressure is (in $\%$)