current inductive
circuit.c. circuit also cause an
opposition current flow, which call reactance.
. circuit, resistance only part the opposition cur-
rent flow.Alternating current theory and electrical machines
195
Resistance
In any circuit, resistance defined opposition current flow. causes the current the circuit lag behind the applied voltage,
as shown Fig.142 constant
f the frequency the supply
L the inductance the circuit by
X
V
I
L
L
L
R
Pure resistance
(R)
V and phase lags 90° leads 90°
Pure inductance
(L)
Pure capacitance
(C)
V
V
I
V V
I
I
I
I
L
V
I C
V
I
V V
I I
FIGURE 10.c.2
Voltage and current relationships resistive, capacitive and inductive circuits. 10.2.
However, a. From
Ohm’s law:
R
V
I
R
R
( )
Ω
Definition
In any circuit, resistance defined as
opposition current flow. current inductive
circuit.
Inductive reactance (XL) the opposition a.c. given the formula:
X fL
L Ω
where
π 3. The inductance and capacitance a.c.
Definition
Inductive reactance (XL) the opposi-
tion a. causes the current the cir-
cuit lag behind the applied voltage
