Baisc Electrical Installation Work
200
Example 1
A coil 0.7
Phasor diagram and impedance triangle. Calculate
(a) the reactance the coil, (b) the impedance the circuit and (c) the current.142 0.15 47.15H connected series with resistor across 100V 50Hz supply.1
π
∴
Ω
Ω
For (b):
Z X
Z
2
2 2
( )
(50 (47.69
Ω
∴ Ω
For (c):
I
V
Z
I
V
(A)
100
68.46A
∴
Ω
Example 2
A 60μF capacitor connected series with 100Ω resistor across 230V supply.1 68.
VL
VC
VT
VR R
VR IR
VT IZ
Z
IXC
R
IZ
IXL
XL
Z
XC
(a) (b) (c)
(a) (b) (c)
For inductive circuit
For capacitive circuit
FIGURE 10.
For (a):
X fL
X
L
L
2 )
2 3.69
1.
.
Calculate (a) the reactance the capacitor, (b) the impedance the circuit and (c) the
current
