Two resistances are given as $R_1 = (10 \pm 0.5) \ \Omega$ and $R_2 = (15 \pm 0.5) \ \Omega$. The percentage error in the measurement of equivalent resistance when they are connected in parallel is (in $\%$)

If the error in measuring the diameter of a circle is $4\%$,the error in the radius of the circle would be (in $\%$)

$A$ body travels uniformly a distance of $(13.8 \pm 0.2) \text{ m}$ in a time $(4.0 \pm 0.3) \text{ s}$. Its velocity with error limits and percentage error is

In an experiment for determination of the focal length of a thin convex lens,the distance of the object from the lens is $10 \pm 0.1 \text{ cm}$ and the distance of its real image from the lens is $20 \pm 0.2 \text{ cm}$. The error in the determination of focal length of the lens is $n \%$. The value of $n$ is. . . . . . .

Error in the measurement of radius of a sphere is $0.2\%$. The error in the calculated value of its volume is ......... $\%$

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. ....... .