Xeerka ugu horreeya ee Kirchhoff wuxuu sidoo kale ugu yeeray xeerka barta isku xirka wuxuu sheegayaa in qulqulka korontada ee gala barta isku xirka uu la mid yahay kan korontada ee ka baxa barta isku xirka. Barta isku xirka ee wareegga korontada waa barta ay ku kulmaan laba ama in ka badan oo ka mid ah labada gudbiye, sida barta a ee sawirka dhinaca.
I waa koronto-wadeyaasha gala barta isgoyska, halka I 1 iyo I 2 ay yihiin koronto-wadeyaasha ka baxa barta isgoyska, I = I 1 + I 2. Tusaale kale, fiiri sawirka hoose.
Aniga ayaa soo galaya hadda koronto, inta aan anigu1, Aniga2, iyo aniga3 waa hirarka korontada ee baxaya, I = I1 + Aniga2 + Aniga3.
Xeerka ugu horreeya ee Kirchhoff wuxuu ku salaysan yahay sharciga ilaalinta ee korontada kaas oo sheegaya in korontada soo socota ay tahay mid weligeed ah, korontada soo socota waa inay la mid noqotaa korontada soo baxda, korontada ma lunto. Korontadu waa koronto ku socota muddo cayiman. Korontada soo gasha barta isku xirka waxay la mid tahay korontada ka soo baxaysa bartaas isku xirka.
Xeerkii ugu horreeyay ee Kirchhoff waxaa sheegay Gustav Kirchhoff (1824-1887), oo ahaa fiisigis Jarmal ah.
Muunad dhibaato 1aad:
I 1 = 2 A, I 2 = 3 A, I 3 = 5 A, I 4 = 3 A. Go'aami I 5!
Solution:
Waan galayaa = Waan ka baxayaa
I 1 + I 3 = I 2 + I 4 + I 5
2 A + 5 A = 3 A + 3 A + I 5
7 A = 6 A + I 5
I 5 = 7 A – 6 A
I 5 = 1 A
Muunad dhibaato 2aad:
I = 10 A, I 1 = 2 A, I 2 = 4 A. Go'aami I 3!
Solution:
Waan galayaa = Waan ka baxayaa
Aniga = Aniga 1 + Aniga 2 + Aniga 3
10 A = 2 A + 4 A + I 3
10 A = 6 A + I 3
I 3 = 10 A – 6 A
I 3 = 4 A
