PROGRAMMABLE LOGIC CONTROLLERS 5TH
EDITION ACTUAL EXAM 2026 QUESTIONS
WITH ANSWERS GRADED A+
◉ PLCs. Answer: A programmable logic controller or PLC is a general-
purpose controller, applicable to many
different types of process control applications.
◉ Programmable. Answer: The end-user is able to program, or instruct,
the PLC to do virtually any control function imaginable.
◉ Ladder Diagram. Answer: Ladder Diagram PLC programs resemble
ladder-style electrical schematics, where vertical power "rails" convey
control power to a set of parallel "rung" circuits containing switch
contacts and relay coils.
◉ Input devices. Answer: Typical devices connecting to a PLC's inputs
include hand switches, process switches, sensors,
analog transmitters (4-20 mA), thermocouples, thermistors, and strain
gauges.
, ◉ Output devices. Answer: Typical devices connecting to a PLC's
outputs include electric lamps, solenoids, relay coils, motor contactors,
analog final control elements (e.g. throttling control valves, variable-
speed motor drives), and audible
buzzers.
◉ NOTE. Answer: Programmable logic controllers are essentially
nothing more than special-purpose, industrial computers. As such, they
are built far more ruggedly than an ordinary personal computer (PC),
and designed to run extremely reliable operating system software.
◉ Cards. Answer: These cards include processors, input and output (I/O)
points, communications ports, and other functions necessary to the
operation of a complete PLC system.
◉ Modular PLCs. Answer: Also known as rack-mounted units, consist
of bases allowing for many independent components, such as the
installation of numerous I/O modules. These are easier to repair.
◉ Fixed PLCs. Answer: Are typically designed to perform basic
functions. They are small and consist of a power supply and the CPU
and I/O systems, which are all housed in one entity. The proper
functioning of all processes largely depends on the flawless execution of
every component.
EDITION ACTUAL EXAM 2026 QUESTIONS
WITH ANSWERS GRADED A+
◉ PLCs. Answer: A programmable logic controller or PLC is a general-
purpose controller, applicable to many
different types of process control applications.
◉ Programmable. Answer: The end-user is able to program, or instruct,
the PLC to do virtually any control function imaginable.
◉ Ladder Diagram. Answer: Ladder Diagram PLC programs resemble
ladder-style electrical schematics, where vertical power "rails" convey
control power to a set of parallel "rung" circuits containing switch
contacts and relay coils.
◉ Input devices. Answer: Typical devices connecting to a PLC's inputs
include hand switches, process switches, sensors,
analog transmitters (4-20 mA), thermocouples, thermistors, and strain
gauges.
, ◉ Output devices. Answer: Typical devices connecting to a PLC's
outputs include electric lamps, solenoids, relay coils, motor contactors,
analog final control elements (e.g. throttling control valves, variable-
speed motor drives), and audible
buzzers.
◉ NOTE. Answer: Programmable logic controllers are essentially
nothing more than special-purpose, industrial computers. As such, they
are built far more ruggedly than an ordinary personal computer (PC),
and designed to run extremely reliable operating system software.
◉ Cards. Answer: These cards include processors, input and output (I/O)
points, communications ports, and other functions necessary to the
operation of a complete PLC system.
◉ Modular PLCs. Answer: Also known as rack-mounted units, consist
of bases allowing for many independent components, such as the
installation of numerous I/O modules. These are easier to repair.
◉ Fixed PLCs. Answer: Are typically designed to perform basic
functions. They are small and consist of a power supply and the CPU
and I/O systems, which are all housed in one entity. The proper
functioning of all processes largely depends on the flawless execution of
every component.
