Kirchhoff's loop law represents the conservation of which physical quantity?

$A$ part of a circuit is shown in the figure. The ratio of the potential differences between the points $A$ and $C$,and the points $D$ and $E$ is

Two ideal batteries of emf $V_1$ and $V_2$ and three resistances $R_1, R_2$ and $R_3$ are connected as shown in the figure. The current in resistance $R_2$ would be zero if:
$(A)$ $V_1=V_2$ and $R_1=R_2=R_3$
$(B)$ $V_1=V_2$ and $R_1=2R_2=R_3$
$(C)$ $V_1=2V_2$ and $2R_1=2R_2=R_3$
$(D)$ $2V_1=V_2$ and $2R_1=R_2=R_3$

The current from the cell for the given circuit is ................ $A$.

The current $I$ in the circuit shown is:

An electrical circuit consists of the resistances $R, r_1, R_2$ and voltage sources $E_1$ and $E_2$ as shown in the figure. The correct equation for the loop $E B C D E$ is