South Carolina Industrial Controls
Technician Certification License Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which of the following BEST describes a PLC (Programmable Logic
Controller) used in industrial control systems?
A. A device that converts AC to DC power
B. A programmable computer used for automation control
C. A mechanical relay with digital output
D. A sensor for measuring current
A PLC is a specialized industrial computer designed to automate
control processes in manufacturing and industrial environments.
2. What does the acronym “HMI” stand for in industrial control systems?
A. Hydraulic Measurement Interface
B. Human Machine Interface
C. High-speed Motor Integration
D. Heavy Mechanical Input
An HMI provides a user interface between operators and automated
machinery.
3. In a three-phase motor control circuit, what is the purpose of a
contactor?
, A. To measure current
B. To switch motor power on and off
C. To provide overload protection
D. To convert phase voltages
Contactors are electrically controlled switches used to energize or
de-energize a motor circuit.
4. Which type of sensor detects the presence of a metallic object without
physical contact?
A. Photoelectric sensor
B. Capacitive sensor
C. Inductive proximity sensor
D. Ultrasonic sensor
Inductive sensors detect metal objects by generating a magnetic field
and sensing changes when metal is present.
5. What is the primary purpose of a motor overload relay?
A. To increase motor speed
B. To protect a motor from excessive current/heat
C. To regulate voltage
D. To reduce noise
Overload relays prevent motor damage by cutting power when
excessive current/heat is detected.
6. In ladder logic programming, what does a “normally open” contact
represent?
A. Circuit is closed when de-energized
B. Circuit closes when activated
C. Circuit is always closed
D. Circuit never completes
Normally open (NO) contacts close when the controlling coil is
energized allowing current to flow.
, 7. Which device converts AC power to DC power in a control panel?
A. Transformer
B. Rectifier
C. Circuit breaker
D. Timer relay
A rectifier changes alternating current into direct current for DC
control circuits.
8. What safety standard is MOST relevant to industrial electrical
installations in the U.S.?
A. ANSI Z87.1
B. ISO 9001
C. NFPA 70 (NEC)
D. OSHA 1910 only
The National Electrical Code (NEC) published by NFPA is the primary
electrical safety standard.
9. A star-delta starter is used to:
A. Increase motor voltage
B. Reduce inrush current during motor starting
C. Convert AC to DC
D. Balance three-phase power
Star-delta starters reduce starting current by initially connecting the
motor in a star configuration.
10. What does an encoder measure in industrial automation?
A. Temperature
B. Pressure
C. Position or speed
D. Voltage
Encoders convert motion into a signal representing position or speed
for feedback control.
Technician Certification License Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which of the following BEST describes a PLC (Programmable Logic
Controller) used in industrial control systems?
A. A device that converts AC to DC power
B. A programmable computer used for automation control
C. A mechanical relay with digital output
D. A sensor for measuring current
A PLC is a specialized industrial computer designed to automate
control processes in manufacturing and industrial environments.
2. What does the acronym “HMI” stand for in industrial control systems?
A. Hydraulic Measurement Interface
B. Human Machine Interface
C. High-speed Motor Integration
D. Heavy Mechanical Input
An HMI provides a user interface between operators and automated
machinery.
3. In a three-phase motor control circuit, what is the purpose of a
contactor?
, A. To measure current
B. To switch motor power on and off
C. To provide overload protection
D. To convert phase voltages
Contactors are electrically controlled switches used to energize or
de-energize a motor circuit.
4. Which type of sensor detects the presence of a metallic object without
physical contact?
A. Photoelectric sensor
B. Capacitive sensor
C. Inductive proximity sensor
D. Ultrasonic sensor
Inductive sensors detect metal objects by generating a magnetic field
and sensing changes when metal is present.
5. What is the primary purpose of a motor overload relay?
A. To increase motor speed
B. To protect a motor from excessive current/heat
C. To regulate voltage
D. To reduce noise
Overload relays prevent motor damage by cutting power when
excessive current/heat is detected.
6. In ladder logic programming, what does a “normally open” contact
represent?
A. Circuit is closed when de-energized
B. Circuit closes when activated
C. Circuit is always closed
D. Circuit never completes
Normally open (NO) contacts close when the controlling coil is
energized allowing current to flow.
, 7. Which device converts AC power to DC power in a control panel?
A. Transformer
B. Rectifier
C. Circuit breaker
D. Timer relay
A rectifier changes alternating current into direct current for DC
control circuits.
8. What safety standard is MOST relevant to industrial electrical
installations in the U.S.?
A. ANSI Z87.1
B. ISO 9001
C. NFPA 70 (NEC)
D. OSHA 1910 only
The National Electrical Code (NEC) published by NFPA is the primary
electrical safety standard.
9. A star-delta starter is used to:
A. Increase motor voltage
B. Reduce inrush current during motor starting
C. Convert AC to DC
D. Balance three-phase power
Star-delta starters reduce starting current by initially connecting the
motor in a star configuration.
10. What does an encoder measure in industrial automation?
A. Temperature
B. Pressure
C. Position or speed
D. Voltage
Encoders convert motion into a signal representing position or speed
for feedback control.
