6, is
lagging the current some angle φ. 10.
.
C
VC VR
R
I
I
VT VT
VR
FIGURE 10.
L
VL VR
R
I
VT
I
VL VT
VR
FIGURE 10.Alternating current theory and electrical machines
199
scale and phase with the current and drawn scale and leading the
current 90°. 10. The phasor addition these two voltages gives the mag-
nitude and direction VT, which leads the current some angle φ. circuit.7(b), by
the theorem Pythagoras, have:
( )
IZ IX
2 X
2
If now divide throughout I2
we have:
Z X
Z X
2 2
2 2
or
Ω
The phasor diagram can simplified the impedance triangle given in
Fig.6 show the voltage phasors, but we
know that IR, IXL, IXC and IZ, and therefore the pha-
sor diagrams (a) and (b) Fig.5 and 10.5
A series circuit and phasor diagram. The voltage will phase with
the current and will lag the current 90°. Figures 10. 10. From Fig.6
A series circuit and phasor diagram.
The impedance triangle
We have now established the general shape the phasor diagram for a
series a.c. 10.7(c).7 must equal. 10.6, the current will flow through the resistor and capaci-
tor causing voltage drops and VC.
In circuit containing resistor and capacitor connected series as
shown Fig. The phasor addition these
voltages equal the total voltage which, can seen Fig
