The value of current in the $6 \,\Omega$ resistance is $....\,A$

In a balanced Wheatstone's network,the resistances in the arms $Q$ and $S$ are interchanged. As a result of this:

In the given figure,the value of $V_{0}$ will be $.....V$.

For the circuit shown in the figure,the current $I$ will be .......$A$.

In the given circuit,the electric currents through $15 \Omega$ and $6 \Omega$ resistors respectively are:

$A$ battery of $10 \;V$ and negligible internal resistance is connected across the diagonally opposite corners of a cubical network consisting of $12$ resistors each of resistance $1 \;\Omega$. Determine the equivalent resistance of the network and the current along each edge of the cube.