Maryland PLC Programmer Certification
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. Which device is primarily used to execute control logic in a PLC
system?
A. Relay switch
B. Microcontroller in sensors
C. Programmable Logic Controller CPU
D. HMI display panel
C
The PLC CPU is responsible for executing the stored control program,
processing inputs, and updating outputs in real time.
2. What is the primary purpose of a PLC input module?
A. Convert digital signals into mechanical motion
B. Receive field signals and convert them into CPU-readable data
C. Store ladder logic programs permanently
D. Provide power to output devices
B
Input modules condition and translate real-world signals into a
format the PLC processor can interpret.
,3. Which programming language is most commonly associated with PLC
ladder logic?
A. Python
B. Assembly language
C. Ladder Diagram (LD)
D. HTML
C
Ladder Diagram is widely used because it visually resembles
electrical relay logic, making it intuitive for technicians.
4. In PLC systems, what does a “scan cycle” refer to?
A. The process of replacing faulty hardware
B. The time taken to update firmware
C. Reading inputs, executing program, and updating outputs
D. Uploading programs from a PC
C
A scan cycle is the continuous loop where the PLC reads inputs,
processes logic, and updates outputs.
5. Which memory type is typically non-volatile in a PLC?
A. RAM
B. ROM or Flash memory
C. Cache memory
D. Virtual memory
B
Non-volatile memory retains program data even when power is
removed, ensuring program persistence.
6. What is the function of an output module in a PLC system?
A. Store logic instructions
B. Execute arithmetic operations
C. Activate field devices based on CPU commands
, D. Monitor network traffic
C
Output modules send control signals from the PLC to actuators such
as motors, valves, and relays.
7. Which PLC programming instruction is used for logical AND
operations?
A. OR coil
B. Series contacts
C. Parallel contacts
D. Timer block
B
Series contacts in ladder logic represent an AND condition where all
inputs must be true for output activation.
8. What is a major advantage of PLCs over traditional relay systems?
A. Higher mechanical wear
B. Easier rewiring for logic changes
C. Requires more physical space
D. Slower processing speed
B
PLCs allow software-based logic changes, eliminating the need for
extensive rewiring.
9. What does the acronym PLC stand for?
A. Process Logic Circuit
B. Programmable Logic Controller
C. Programmed Load Converter
D. Peripheral Logic Controller
B
PLC stands for Programmable Logic Controller, a digital industrial
control system.
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. Which device is primarily used to execute control logic in a PLC
system?
A. Relay switch
B. Microcontroller in sensors
C. Programmable Logic Controller CPU
D. HMI display panel
C
The PLC CPU is responsible for executing the stored control program,
processing inputs, and updating outputs in real time.
2. What is the primary purpose of a PLC input module?
A. Convert digital signals into mechanical motion
B. Receive field signals and convert them into CPU-readable data
C. Store ladder logic programs permanently
D. Provide power to output devices
B
Input modules condition and translate real-world signals into a
format the PLC processor can interpret.
,3. Which programming language is most commonly associated with PLC
ladder logic?
A. Python
B. Assembly language
C. Ladder Diagram (LD)
D. HTML
C
Ladder Diagram is widely used because it visually resembles
electrical relay logic, making it intuitive for technicians.
4. In PLC systems, what does a “scan cycle” refer to?
A. The process of replacing faulty hardware
B. The time taken to update firmware
C. Reading inputs, executing program, and updating outputs
D. Uploading programs from a PC
C
A scan cycle is the continuous loop where the PLC reads inputs,
processes logic, and updates outputs.
5. Which memory type is typically non-volatile in a PLC?
A. RAM
B. ROM or Flash memory
C. Cache memory
D. Virtual memory
B
Non-volatile memory retains program data even when power is
removed, ensuring program persistence.
6. What is the function of an output module in a PLC system?
A. Store logic instructions
B. Execute arithmetic operations
C. Activate field devices based on CPU commands
, D. Monitor network traffic
C
Output modules send control signals from the PLC to actuators such
as motors, valves, and relays.
7. Which PLC programming instruction is used for logical AND
operations?
A. OR coil
B. Series contacts
C. Parallel contacts
D. Timer block
B
Series contacts in ladder logic represent an AND condition where all
inputs must be true for output activation.
8. What is a major advantage of PLCs over traditional relay systems?
A. Higher mechanical wear
B. Easier rewiring for logic changes
C. Requires more physical space
D. Slower processing speed
B
PLCs allow software-based logic changes, eliminating the need for
extensive rewiring.
9. What does the acronym PLC stand for?
A. Process Logic Circuit
B. Programmable Logic Controller
C. Programmed Load Converter
D. Peripheral Logic Controller
B
PLC stands for Programmable Logic Controller, a digital industrial
control system.
