ABSTRACT
The laws which determine the currents and voltage drops in a.c. networks are:
(a) current, I=V/Z, where Z is the complex impedance and V the voltage across the impedance;
(b) the laws for impedances in series and parallel, i.e. total impedance,
and 1 ZT
= 1 Z1
+ 1 Z2
+ 1 Z3
+·· ·+ 1 Zn
forn impe-
dances connected in parallel; and
(c) Kirchhoff’s laws, which may be stated as: (i) ‘At any point in an electrical circuit the phasor sum of the currents flowing towards that junction is equal to the phasor sum of the currents flowing away from the junction.’