In the given circuit diagram,a wire is joining points $B$ and $D$. The current in this wire is ............. $A$.

Five equal resistances are connected in a network as shown in the figure. The net resistance between the points $A$ and $B$ is

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

To measure the temperature coefficient of resistivity $\alpha$ of a semiconductor,an electrical arrangement shown in the figure is prepared. The arm $BC$ is made up of the semiconductor. The experiment is being conducted at $25^{\circ} C$ and the resistance of the semiconductor arm $BC$ is $3 \ m\Omega$. Arm $BC$ is cooled at a constant rate of $2^{\circ} C / s$. If the galvanometer $G$ shows no deflection after $10 \ s$,then $\alpha$ is:

In a balanced Wheatstone bridge,the current in the galvanometer is zero. It remains zero when:

In the figure shown,the current in the $10 \, V$ battery is close to