Letter Iu

Inductive Reactance
The opposition to alternating current resulting from circuit
inductance. Inductive reactance is directly proportional to
frequency (f) and inductance (l). The symbol for inductive
reactance is “XL” The unit for inductive reactance is the ohm.



Inductor
A device manufactured to have a specific inductance. An
inductor is often made from a coil of wire and is sometimes
called a coil or choke.


Input/Output (I/O) System
The part of a control system that interfaces to the real world.
The I/O system accepts signals from switches and sensors, and
provides signals to actuating and display devices.