Answer: KCL is applicable only to junctions and loops in a network.
Kirchhoff's rule are useful for the analysis of electric circuits. There are two rules namely the Junction rule and the Loop rule. The details on both the rules can be read below:
Junction Rule: It states that at any junction in a network, the sum of the currents flowing in the junction is equal to the sum of flowing out of the junction.
Loop Rule: The algebraic sum of changes in potential around any closed loop should be zero.
In the given figure, the current entering at junction ‘a’ is I3 whereas the current leaving the junction is I1 and I2. Hence, after applying the junction rule, we get the equation I1 + I2 = I3
Similarly if we apply loop rule in the ‘ahdcba’ loop, we get –30I1 – 41I3 + 45 = 0 whereas in ‘ahdefga’ loop, we get –30I1 + 21I2 – 80 = 0.
Where is Kirchhoff's Current Law applicable in a network?
Kirchhoff's Current Law is applicable to the junction and loop in a network.