The equivalent resistance across $A$ and $B$ as shown in the figure is ............. $\Omega$.

Four equal resistors,each of resistance $10 \,\Omega$,are connected as shown in the circuit diagram. The equivalent resistance between $A$ and $B$ is ............. $\Omega$.

Three resistors each of $4\,\Omega$ are connected together to form a network. The equivalent resistance of the network cannot be ............ $\Omega$.

$A$ wire has a resistance of $24\,\Omega$ and is bent into the shape shown in the figure. The effective resistance between $A$ and $B$ is .............. $\Omega$.

$A$ man has some identical resistors,each with a resistance $R = 10 \, \Omega$ and a maximum current rating of $1 \, \text{A}$. He needs to create a circuit with an equivalent resistance of $5 \, \Omega$ that can handle a total current of $4 \, \text{A}$. What is the minimum number of such resistors required?

$A$ wire of resistance $R$ is bent into a triangular pyramid as shown in the figure,with each segment having the same length. The resistance between points $A$ and $B$ is $R / n$. The value of $n$ is