$A$ meter bridge is set up as shown,to determine an unknown resistance '$X$' using a standard $10 \ \Omega$ resistor. The galvanometer shows a null point when the tapping key is at the $52 \ cm$ mark. The end corrections are $1 \ cm$ and $2 \ cm$ respectively for the ends $A$ and $B$. The determined value of '$X$' is (in $\Omega$)

In the experimental setup of a meter bridge shown in the figure,the null point is obtained at a distance of $40\,cm$ from $A$. If a $10\,\Omega$ resistor is connected in series with $R_1$,the null point shifts by $10\,cm$. The resistance that should be connected in parallel with $(R_1 + 10)\,\Omega$ such that the null point shifts back to its initial position is .............. $\Omega$.

The resistances in the left and right gaps of a balanced metre bridge are $12 \Omega$ and $36 \Omega$ respectively. If the resistances are interchanged,the balance point shifts by:

In a meter bridge experiment,the balance point is obtained if the gaps are closed by $2 \Omega$ and $3 \Omega$ resistors. $A$ shunt of $X \Omega$ is added to the $3 \Omega$ resistor to shift the null point by $22.5 \text{ cm}$. The value of $X$ is: (in $\Omega$)

Two resistors $2 \Omega$ and $3 \Omega$ are connected in the gaps of a meter bridge as shown in the figure. The null point is obtained with the contact of the jockey at some point on the wire $XY$. When an unknown resistor $R$ is connected in parallel with the $3 \Omega$ resistor, the null point is shifted by $22.5 \text{ cm}$ toward $Y$. The resistance of the unknown resistor $R$ is . . . . . . $\Omega$.

Explain how the value of an unknown resistor can be obtained by using a meter bridge.