In the Wheatstone's bridge (shown in figure) $X = Y$ and $A > B$. The direction of the current between $a$ and $b$ will be

In the circuit shown,what is the potential difference $V_{PQ}$?

The given figure shows a network of resistances and two batteries. Which of the two batteries is getting charged?

$A$ 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 ............. $\Omega$.

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 $Omega$)

Four resistors are connected as shown in the figure. $A$ $6\,V$ battery of negligible resistance is connected across terminals $A$ and $C$. The potential difference across terminals $B$ and $D$ will be ............. $V$.