1|Page
SACA CERTIFICATION C-101 STUDY GUIDE EXAM QUESTIONS
AND ACTUAL ANSWERS 2025-2026, VERIFIED AND 100%
CORRECT ALREADY GRADED A+
1.
Which of the following is the main function of a PLC in industrial
automation?
A. Store energy for emergency shutdowns
B. Provide mechanical movement to actuators
C. Monitor inputs and control outputs based on logic programming
D. Transmit power to sensors
Answer: C
Rationale: A PLC processes input signals, executes logic, and controls
outputs.
2.
Which safety device is most commonly used to immediately disconnect
power during an emergency?
A. Circuit breaker
,2|Page
B. Thermal overload
C. Emergency stop push button
D. Relay
Answer: C
Rationale: Emergency stop (E-stop) is designed for rapid power
disconnection in hazardous conditions.
3.
Which type of sensor is best for detecting the presence of metallic objects?
A. Ultrasonic sensor
B. Photoelectric sensor
C. Inductive proximity sensor
D. Capacitive proximity sensor
Answer: C
Rationale: Inductive sensors detect metal using electromagnetic fields.
4.
The term “lockout/tagout (LOTO)” refers to:
A. Securing mechanical parts to prevent vibration
B. Ensuring machinery is de-energized and cannot be restarted during
,3|Page
maintenance
C. Labeling wires for identification
D. Programming safety interlocks
Answer: B
Rationale: LOTO is a safety procedure to protect workers from accidental
machine start-up.
5.
Which device converts electrical signals into mechanical motion?
A. Sensor
B. Actuator
C. PLC
D. HMI
Answer: B
Rationale: Actuators (motors, solenoids, etc.) turn electrical input into
motion.
6.
Which of the following is a discrete input?
A. Pressure sensor giving 0–10V
, 4|Page
B. Temperature probe with analog signal
C. Push button switch (ON/OFF)
D. Potentiometer
Answer: C
Rationale: Discrete inputs are binary (ON/OFF).
7.
What does an HMI (Human-Machine Interface) primarily allow operators
to do?
A. Generate mechanical force
B. Maintain hydraulic systems
C. Monitor and control automated processes
D. Store PLC programs
Answer: C
Rationale: HMIs provide user interaction with automation systems.
8.
Which communication protocol is widely used in industrial Ethernet
networks?
A. RS-232
SACA CERTIFICATION C-101 STUDY GUIDE EXAM QUESTIONS
AND ACTUAL ANSWERS 2025-2026, VERIFIED AND 100%
CORRECT ALREADY GRADED A+
1.
Which of the following is the main function of a PLC in industrial
automation?
A. Store energy for emergency shutdowns
B. Provide mechanical movement to actuators
C. Monitor inputs and control outputs based on logic programming
D. Transmit power to sensors
Answer: C
Rationale: A PLC processes input signals, executes logic, and controls
outputs.
2.
Which safety device is most commonly used to immediately disconnect
power during an emergency?
A. Circuit breaker
,2|Page
B. Thermal overload
C. Emergency stop push button
D. Relay
Answer: C
Rationale: Emergency stop (E-stop) is designed for rapid power
disconnection in hazardous conditions.
3.
Which type of sensor is best for detecting the presence of metallic objects?
A. Ultrasonic sensor
B. Photoelectric sensor
C. Inductive proximity sensor
D. Capacitive proximity sensor
Answer: C
Rationale: Inductive sensors detect metal using electromagnetic fields.
4.
The term “lockout/tagout (LOTO)” refers to:
A. Securing mechanical parts to prevent vibration
B. Ensuring machinery is de-energized and cannot be restarted during
,3|Page
maintenance
C. Labeling wires for identification
D. Programming safety interlocks
Answer: B
Rationale: LOTO is a safety procedure to protect workers from accidental
machine start-up.
5.
Which device converts electrical signals into mechanical motion?
A. Sensor
B. Actuator
C. PLC
D. HMI
Answer: B
Rationale: Actuators (motors, solenoids, etc.) turn electrical input into
motion.
6.
Which of the following is a discrete input?
A. Pressure sensor giving 0–10V
, 4|Page
B. Temperature probe with analog signal
C. Push button switch (ON/OFF)
D. Potentiometer
Answer: C
Rationale: Discrete inputs are binary (ON/OFF).
7.
What does an HMI (Human-Machine Interface) primarily allow operators
to do?
A. Generate mechanical force
B. Maintain hydraulic systems
C. Monitor and control automated processes
D. Store PLC programs
Answer: C
Rationale: HMIs provide user interaction with automation systems.
8.
Which communication protocol is widely used in industrial Ethernet
networks?
A. RS-232
