In the arrangement of resistors shown in the diagram,the potential difference between $B$ and $D$ will be zero when the unknown resistance $X$ is ............... $\Omega$.

If the resistances are chosen for the circuit shown in the figure in such a way that no current flows through the battery with emf $E_1 = 2 \ V$,the voltage $V_2$ across $R_2$ and the current $I_3$ flowing through $R_3$ are respectively,

$A$ $16\, \Omega$ wire is bent to form a square loop. $A$ $9\, V$ supply having an internal resistance of $1\, \Omega$ is connected across one of its sides. The potential drop across the diagonals of the square loop is $.......\, \times 10^{-1}\, V$.

In a post office box arrangement used to determine the value of an unknown resistance,the unknown resistance should be connected between:

In the network shown in the figure,each of the resistance is equal to $2\,\Omega$. The resistance between the points $A$ and $B$ is .............. $\Omega$.

$ABCD$ is a square where each side is a uniform wire of resistance $1\,\Omega$. $A$ point $E$ lies on $CD$ such that if a uniform wire of resistance $1\,\Omega$ is connected across $AE$ and a constant potential difference is applied across $A$ and $C$,then $B$ and $E$ are equipotential.