In a meter bridge experiment for measuring an unknown resistance '$S$',the null point is obtained at a distance of $30 \ cm$ from the left side,as shown at point $D$. If $R$ is $5.6 \ k\Omega$,then the value of the unknown resistance '$S$' will be $\Omega$.

In a sensitive meter bridge apparatus,the bridge wire should possess:

$A$ student obtained the following observations in an experiment of a meter bridge to find the unknown resistance of the circuit. The most accurate value of the unknown resistance is ............ $\Omega$.

$S.No.$	$R$	$l$	$100-l$	$S = \left( \frac{100-l}{l} \right)R$
$1$	$20\,\Omega$	$43$	$57$	$26.51\,\Omega$
$2$	$30\,\Omega$	$51$	$49$	$28.82\,\Omega$
$3$	$40\,\Omega$	$59$	$41$	$27.80\,\Omega$
$4$	$60\,\Omega$	$70$	$30$	$25.71\,\Omega$

In the meter bridge experiment, the length $AB$ of the wire is $1 \, m$. The resistors $X$ and $Y$ have values $5 \, \Omega$ and $2 \, \Omega$ respectively. When a shunt resistance $S$ is connected in parallel to $X$, the balancing point is found to be $0.625 \, m$ from $A$. Then, the resistance of the shunt $S$ is

$A$ resistance of $20 \Omega$ is connected in the left gap of a metre bridge and an unknown resistance greater than $20 \Omega$ is connected in the right gap. When these resistances are interchanged,the balance point shifts by $20 \text{ cm}$. The unknown resistance is (in $\Omega$)

In a meter-bridge experiment,a resistance of $18 \Omega$ is connected in the left gap and an unknown resistance $R$ is connected in the right gap. The null point is obtained at $\ell_{1}$ from the left end. If the unknown resistance is replaced by $(\frac{R}{3}) \Omega$,the null point is obtained at $1.5 \ell_{1}$. The unknown resistance $R$ is: (in $\Omega$)