Shown in the figure below is a meter-bridge set up with null deflection in the galvanometer. The value of the unknown resistor $R$ is ............. $\Omega$.

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

The resistances in the two arms of a meter bridge are $5\,\Omega$ and $R\,\Omega$,respectively. When the resistance $R$ is shunted with an equal resistance,the new balance point is at $1.6\,l_1$. The resistance $R$ is ................. $\Omega$.

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 $Omega$)

The resistance of the meter bridge wire $AB$ in the given figure is $4\,\Omega$. With a cell of emf $\varepsilon_1 = 0.5\,\text{V}$ and rheostat resistance $R_{h1} = 2\,\Omega$,the null point is obtained at point $J$. When the cell is replaced by another one of emf $\varepsilon_2$,the same null point $J$ is found for $R_{h2} = 6\,\Omega$. The emf $\varepsilon_2$ is ................. $\text{V}$.

In a metre-bridge experiment,the balance point is obtained when the gaps are closed by $2 \Omega$ and $3 \Omega$ resistors. $A$ shunt of $x \Omega$ is added in parallel to the $3 \Omega$ resistor to shift the balance point by $22.5 \ cm$. The value of $x$ is: (in $Omega$)