In an experiment of a simple pendulum,the time period measured was $50 \, s$ for $25$ vibrations when the length of the simple pendulum was taken as $100 \, cm$. If the least count of the stopwatch is $0.1 \, s$ and that of the meter scale is $0.1 \, cm$,then the maximum possible error in the value of $g$ is .......... $\%$

The time period of a simple pendulum is given by $T = 2 \pi \sqrt{\frac{\ell}{g}}$. The measured value of the length of the pendulum is $10 \ cm$ known to a $1 \ mm$ accuracy. The time for $200$ oscillations of the pendulum is found to be $100 \ s$ using a clock of $1 \ s$ resolution. The percentage accuracy in the determination of $g$ using this pendulum is $x$. The value of $x$ to the nearest integer is ...........$\%$

Thickness of a pencil measured by using a screw gauge (least count $0.001 \,cm$) comes out to be $0.802 \,cm$. The percentage error in the measurement is ........... $\%$

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

$Assertion$ : The error in the measurement of radius of the sphere is $0.3\%$. The permissible error in its surface area is $0.6\%$.
$Reason$ : The permissible error is calculated by the formula $\frac{\Delta A}{A} = \frac{4\Delta r}{r}$.