Kirchhoff's Current Law:

Kirchhoff's second law is known as his current law and states: "the current arriving is equal to the current leaving at any junction point in a circuit." Thus, if 15 amperes of current arrives at a junction which has two paths leading away from it, 15 amperes will  divide between the two branches, other than a total of 15 amperes have to leave the junction. We are already familiar along with Kirchhoff's current law from parallel circuits, which is, the sum of the branch currents is equal to the  total  current  entering  the branches, as well as the total current leaving the  branches that display in the figure.

Figure: Illustration of Kirchhoff's Current Law

In equation form, Kirchhoff's current law may be expressed:

I_IN - I_OUT    = 0                                     (2-16)

or

I_IN     = I_OUT

Generally Kirchhoff's current law is not used through itself, but along with the voltage law, in solving a problem.