In the given electrical circuit,which one of the following equations is correct?

In the circuit shown,the current in the $1\,\Omega$ resistor is

Five current-carrying conductors meet at point $P$. What is the magnitude and direction of the current in conductor $PQ$?

In the Wheatstone's bridge shown,$P = 2\,\Omega$,$Q = 3\,\Omega$,$R = 6\,\Omega$ and $S = 8\,\Omega$. In order to obtain balance,the shunt resistance across '$S$' must be ............. $\Omega$.

$A$ Wheatstone bridge is initially at room temperature and all arms of the bridge have the same value of resistance $(R_1=R_2=R_3=R_4=R)$. When $R_3$ is heated to some temperature, its resistance value increases by $10 \%$. The potential difference $(V_a - V_b)$ (after $R_3$ is heated) is . . . . . . $V$. Given the total voltage is $40 \text{ V}$.

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