For the circuit given below, the Kirchhoff's loop rule for the loop $BCDEB$ is given by the equation

Kirchhoff's second law, also known as the Kirchhoff's voltage law (KVL). By Kirchhoff's voltage law the algebraic sum of all the EMF's and potential difference across each resistor is equal to zero it means, in the above circuit, 

$-I_2{R}_2-E_2+E_3+I_3{R}_1=0$ $\Rightarrow I_2{R}_2+E_2-E_3-I_3{R}_1=0$.