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

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

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 $Omega$)

In the circuit shown in the adjoining figure,the current between $B$ and $D$ is zero. The unknown resistance $X$ is ................ $\Omega$.

In the following electrical network,the value of $I$ is (in $A$)

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