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

Current measured by the ammeter $(A)$ in the given circuit when no current flows through the $10\,\Omega$ resistance is . . . . . . $A$.

In the following Wheatstone bridge,$P/Q = R/S$. If key $K$ is closed,then the galvanometer will show deflection:

The figure shows a part of an electric circuit. The potentials at points $a$,$b$,and $c$ are $30\,V$,$12\,V$,and $2\,V$ respectively. The current through the $20\,\Omega$ resistor will be $........\,A$.

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

Five conductors meet at a point $x$ as shown in the figure. What is the current flowing through the fifth conductor?