Accuracy of measurement is determined by

The measured value of the length of a simple pendulum is $20 \ cm$ with $2 \ mm$ accuracy. The time for $50$ oscillations was measured to be $40 \ s$ with $1 \ s$ resolution. From these measurements,the accuracy in the measurement of acceleration due to gravity is $N \%$. The value of $N$ is:

The random error in the arithmetic mean of $100$ observations is $x$. What is the random error in the arithmetic mean of $400$ observations?

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 percentage error in the measurement of mass of a body and its speed are $0.73\%$ and $1.84\%$ respectively. The percentage error in the measurement of its momentum and kinetic energy are respectively

The initial and final temperatures of water in a container are observed to be $16 \pm 0.6 \ ^\circ C$ and $56 \pm 0.3 \ ^\circ C$. What will be the rise in temperature of the water?