A cube is made from $12$ identical wires. Current enters one corner of the cube and it leaves the opposite corner. If the resistance of each wire is $r$, then equivalent resistance will be

Each of the resistance in the net work shown in the figure is equal to $R$. The resistance between the terminals $A$ and $B$ is

In the circuit shown here, what is the value of the unknown resistor $R$, so, that the total resistance of the circuit between points $P$ and $Q$ is also equal to $R$?

In the net work shown, the equivalent resistance between $A$ and $B$ is

In the given net work of resistances, the effective resistance between $A$ and $B$ is

The equivalent resistance between points $A$ and $B$, of an infinite net work of resistances, each of $1 \mathrm{\Omega }$, connected as shown, is