In the adjoining circuit,the galvanometer $G$ shows zero deflection. If the batteries $A$ and $B$ have negligible internal resistance,the value of the resistor $R$ will be .............. $\Omega$.

Four resistors $A, B, C$ and $D$ form a Wheatstone bridge. The bridge is balanced when $C = 100 \ \Omega$. If $A$ and $B$ are interchanged,the bridge balances for $C = 121 \ \Omega$. The value of $D$ is: (in $\Omega$)

The electric current $i$ in the circuit shown is (in $\text{ A}$)

$A$ $16\, \Omega$ 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 $.......\, \times 10^{-1}\, V$.

Twelve equal resistors,each of resistance $R$,are connected to form a skeleton cube. The equivalent resistance between two diagonally opposite corners is:

Determine the current in each branch of the network shown in Figure.