$$ \sum I_{in} = \sum I_{out} $$
Gustav Kirchhoff, a German physicist, established two rules in 1845 that act as the "traffic laws" for electricity. They are essentially applications of the and the Conservation of Energy . Mastering these laws unlocks the ability to calculate currents and voltages in any circuit configuration. Part 1: The Theory Explained Before diving into the questions found in your PDF resources, let us clearly define the laws. 1. Kirchhoff’s First Law (The Current Law) Statement: The algebraic sum of the currents entering a junction (or node) is equal to the algebraic sum of the currents leaving the junction. kirchhoff 39-s laws questions and answers pdf a level
If a wire carries $3A$ into a junction and one branch carries $1A$ away, the other branch must carry $2A$ away. 2. Kirchhoff’s Second Law (The Voltage Law) Statement: The sum of the electromotive forces (e.m.f.) in any closed loop in a circuit is equal to the sum of the potential differences (p.d.) across the components in that loop. $$ \sum I_{in} = \sum I_{out} $$ Gustav