The density of a cube is measured by measuring its mass and length of its sides. The percentage error in the measurement of mass and length are $5 \%$ and $6 \%$ respectively. The percentage error in the measurement of density is (in $\%$)

What is the fractional error in $g$ calculated from $T = 2\pi \sqrt {l/g}$? Given fractional errors in $T$ and $l$ are $\pm x$ and $\pm y$ respectively?

"It is advisable to use an instrument with the smallest possible least count." Explain this statement.

When two resistors of resistances $R_1=(200 \pm 2) \Omega$ and $R_2=(400 \pm 4) \Omega$ are connected in series,then the equivalent resistance of the combination is

Write the types of errors in the measurement of a physical quantity and explain them.

Three students $S_{1}, S_{2}$ and $S_{3}$ perform an experiment for determining the acceleration due to gravity $(g)$ using a simple pendulum. They use different lengths of pendulum and record time for different number of oscillations. The observations are as shown in the table.

Student No.	Length of pendulum $(cm)$	No. of oscillations $(n)$	Total time for oscillations $(s)$	Time period $(s)$
$1.$	$64.0$	$8$	$128.0$	$16.0$
$2.$	$64.0$	$4$	$64.0$	$16.0$
$3.$	$20.0$	$4$	$36.0$	$9.0$

(Least count of length $= 0.1 \, cm$,least count for time $= 0.1 \, s$)
If $E_{1}, E_{2}$ and $E_{3}$ are the percentage errors in $g$ for students $1, 2$ and $3$ respectively,then the minimum percentage error is obtained by student no. ....... .