In the following electrical network, the value of $I$ is (in $\text{ A}$)

Two batteries $V_1$ and $V_2$ are connected to three resistors as shown below. If $V_1=2 \,V$ and $V_2=0 \,V$,then the current $I=3 \,mA$. If $V_1=0 \,V$ and $V_2=4 \,V$,then the current $I=4 \,mA$. Now,if $V_1=10 \,V$ and $V_2=10 \,V$,then the current $I$ will be ............ $\,mA$.

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

If in the experiment of Wheatstone's bridge,the positions of cells and galvanometer are interchanged,then the balance point will

Two cells of voltage $10 \ V$ and $2 \ V$ and internal resistances $10 \ \Omega$ and $5 \ \Omega$ respectively,are connected in parallel with the positive end of $10 \ V$ battery connected to the negative pole of $2 \ V$ battery (figure). Find the effective voltage and effective resistance of the combination.

The figure below shows currents in a part of an electric circuit. The current $i$ is ............. $A$.