Kirchhoffs Current law

Kirchhoff is also credited with developing the following equally important relationship between the currents of a network, called Kirchhoff's current law (KCL):

What is Kirchhoff's Current Law?

The law can also be stated in the following way: In equation form, the above statement can be written as follows:

$$\bbox[5px,border:1px solid red] {\color{blue}{ \sum I_i = \sum I_o }}$$

Eq.(1)

with Ii representing the current entering, or "in," and Io representing the current leaving, or "out." In Fig. No. 1, for example, the shaded area can enclose an entire system or a complex network, or it can simply provide a connection point (junction) for the displayed currents. In each case, the current entering must equal that leaving, as required by Eq. (1): $$\sum I_i = \sum I_o$$ $$ I_1 + I_4 = I_2 + I_3$$ $$ 4A + 8A = 2A + 10A$$ $$12A = 12A$$ In the next example, unknown currents can be determined by applying Kirchhoff's current law. Remember to place all current levels entering the junction to the left of the equals sign and the sum of all currents leaving the junction to the right of the equals sign. In technology, the term node is commonly used to refer to a junction of two or more branches. Therefore, this term is used frequently in the analyses to follow.