Find the value of the current through the $2\,\Omega$ resistance for the given circuit. (in $,A$)

The circuit shown is in a steady state. Now,when the switch is closed,the galvanometer shows no deflection. Then the correct relation is:

See the electrical circuit shown in the adjoining figure. Which of the following equations is a correct equation for it?

Consider the circuit shown in the figure. The current $I_3$ is equal to

$A$ Wheatstone's bridge is balanced with a resistance of $625\, \Omega$ in the third arm,where $P, Q$ and $S$ are in the $1^{st}, 2^{nd}$ and $4^{th}$ arm respectively. If $P$ and $Q$ are interchanged,the resistance in the third arm has to be increased by $51\,\Omega$ to secure balance. The unknown resistance in the fourth arm is ............. $\Omega$.

Which of the following statements is false?