Students $A, B$ and $C$ measure the length of a room using a $25 \,m$ long measuring tape of least count $0.5 \,cm$,a meter-scale of least count $0.1 \,cm$,and a foot-scale of least count $0.05 \,cm$,respectively. If the actual length of the room is $9.5 \,m$,which of the following students will report the lowest relative error in the measured length?

The resistance $R = \frac{V}{I}$,where $V = (50 \pm 2) \; V$ and $I = (20 \pm 0.2) \; A$. The percentage error in $R$ is $x\%$. The value of $x$ to the nearest integer is .........

Students $I$,$II$,and $III$ perform an experiment for measuring the acceleration due to gravity $(g)$ using a simple pendulum. They use different lengths of the pendulum and/or record time for different numbers of oscillations. The observations are shown in the table. Least count for length $= 0.1 \text{ cm}$. Least count for time $= 0.1 \text{ s}$.

Student	Length $(cm)$	Oscillations $(n)$	Total Time $(s)$	Time Period $(s)$
$I$	$64.0$	$8$	$128.0$	$16.0$
$II$	$64.0$	$4$	$64.0$	$16.0$
$III$	$20.0$	$4$	$36.0$	$9.0$

If $E_{I}$,$E_{II}$,and $E_{III}$ are the percentage errors in $g$,i.e.,$(\frac{\Delta g}{g} \times 100)$ for students $I$,$II$,and $III$ respectively,which of the following is correct?

The length and width of a rectangular room are measured to be $3.95 \pm 0.05 \,m$ and $3.05 \pm 0.05 \,m$,respectively. The area of the floor is .................... $m^2$

$A$ projectile is thrown with velocity $U = 20 \ m/s \pm 5\%$ at an angle $60^{\circ}.$ If the projectile falls back on the ground at the same level,then which of the following values in $m$ cannot be a possible answer for the range?

The voltage across a lamp is $(6.0 \pm 0.3) \text{ V}$ and the current passing through it is $(4.0 \pm 0.1) \text{ A}$. The power consumed in watt will be (using percentage error):