# Electrodynamics/Kirchoff's Laws

Application of the loop law requires careful attention to the direction of the current. Starting at ${\displaystyle \varepsilon _{1}}$ and taking a clockwise path through ${\displaystyle R_{1}}$, we have: ${\displaystyle \varepsilon _{1}-I_{1}R_{1}-\varepsilon _{2}+I_{2}R_{2}=0.}$. The node sign convention is easier to grasp: Here,${\displaystyle I_{1}+I_{2}=I_{3}}$.