The value of current through the $20\,\Omega$ resistor is .................. $A$.

In a Wheatstone bridge (see figure),resistances $P$ and $Q$ are approximately equal. When $R = 400 \,\Omega$,the bridge is balanced. On interchanging $P$ and $Q$,the value of $R$ for balance is $405 \,\Omega$. The value of $X$ is close to ................. $\Omega$. (in $.5$)

In the balanced condition,the values of the resistances of the four arms of a Wheatstone bridge are shown in the figure below. The resistance $R_3$ has a temperature coefficient of $0.0004 \ {}^{\circ}C^{-1}$. If the temperature of $R_3$ is increased by $100 \ {}^{\circ}C$,the voltage developed between $S$ and $T$ will be. . . . . . . volt.

The current drawn from the battery in the given network is (Internal resistance of the battery is negligible). (in $A$)

What is the value of the current flowing through the galvanometer in the balanced condition of a Wheatstone bridge?

If ${V_{AB}} = 4\,V$ in the given figure,then resistance $X$ will be .............. $\Omega$.