 
TM 9254
73.
Alternating Current  Continued
(3)
Inductive Reactance. The reactance of an inductor is calculated by the formula:
_{XL }= 2 p fL
Where:
_{XL}is the inductive reactance in ohms.
f
is the frequency in hertz.
L
is the inductance in henries.
p
is the constant 3.14159.
(4)
Inductance. The total inductance for a circuit can be calculated using the formulas in figure 77.
For inductors in series:
^{L}T
= L_{1} + L_{2} + L_{2}
For more than two inductors in parallel:
^{L}T
=
1
L_{1} + L_{2} + L_{2}
For two inductors in parallel
^{L}T
= L_{1} + L_{2}
L_{1} + L_{2}
Figure 77. Inductance Formulas
(5)
General Formula. As stated earlier the impedance of an AC circuit is the total opposition to the flow of
current within the circuit. The general forms of the formulas for calculating impedance are given below:
77
