AC1 Fundamentals Unit 4 – Inductive Reactance
UNIT 4 – INDUCTIVE REACTANCE
UNIT OBJECTIVE
At the completion of this unit, you will be able to determine the characteristics of resistive-
inductive (RL) circuits by using an oscilloscope and given information.
UNIT FUNDAMENTALS
There are many similarities and differences between capacitive reactance (XC) and inductive
reactance (XL). They work in opposition to each other when subjected to an ac signal. Inductive
reactance (XL) will be studied first.
The amount of opposition an inductor (L) offers to ac circuit current is measured by the
resistance it offers to the power source (Vac).
Vac
XL =
IL1
This apparent resistance is called inductive reactance (XL)and is measured in ohms.
If inductance increases (larger inductor value), inductive reactance (XL) increases; if inductance
decreases, XL decreases.
Increases in the frequency of the power source (Vac) increase the inductive reactance (XL); if
frequency decreases, XL decreases.
Inductive reactance (XL) does not depend on the amplitude of the power source.