Examination
50 Comprehensive Multiple-Choice Questions with Detailed Answer Key &
Technical Rationales
Position / Craft: Industrial Total Questions: 50 Multiple-
Maintenance Technician Choice Questions
Core Technical Domains: Time Allowed: 60 Minutes
Electrical, Hydraulics, Mechanical, (Suggested)
HVAC & Safety
SECTION 1: EXAMINATION QUESTIONS
Instructions: Select the single best answer for each of the following 50
technical questions. Questions cover core maintenance technician craft
domains including electrical troubleshooting, hydraulics/pneumatics,
mechanical power transmission, HVAC/facilities, and OSHA safety standards.
Refer to Section 2 for answer keys and detailed rationales.
,--- Domain: Electrical Systems & Troubleshooting ---
Question 1. According to Ohm's Law, what is the current flowing
through a 240V heating element with a resistance of 20 Ohms?
A. 12 Amps
B. 24 Amps
C. 4,800 Amps
D. 0.08 Amps
Question 2. Which meter setting MUST be used to verify zero energy
state during an electrical Lockout/Tagout (LOTO) procedure?
A. AC/DC Voltage mode verified on a known live source before and after
testing
B. Resistance (Ohms) mode with power applied
C. Amperage mode using inline leads
D. Continuity mode without checking meter functionality
Question 3. What is the primary function of an overload relay in a three-
phase motor starter circuit?
A. To protect the motor circuit against instant high-current short circuits
B. To protect the motor windings from sustained over-current conditions
and overheating
C. To step down control circuit voltage from 480V to 120V
D. To reverse motor shaft rotation automatically
Question 4. How are two 12V direct current (DC) batteries connected to
supply 24V to an industrial PLC panel?
A. In parallel (Positive to Positive, Negative to Negative)
B. In series (Positive terminal of battery 1 to Negative terminal of battery
2)
C. In delta configuration
D. Through a step-up transformer
,Question 5. What component in a Variable Frequency Drive (VFD)
converts incoming 3-phase AC voltage into direct current (DC)?
A. Inverter bank
B. DC Bus capacitor
C. Rectifier bridge
D. Chopper resistor
Question 6. What instrument is used to test the insulation resistance of
480V electric motor stator windings?
A. Clamp-on ammeter
B. Megohmmeter (Megger)
C. Oscilloscope
D. Wheatstone bridge
Question 7. In a ladder logic diagram, what symbol is represented by two
parallel vertical lines with a diagonal slash between them (--/--)??
A. Normally Open (NO) contact
B. Normally Closed (NC) contact
C. Output relay coil
D. Timer On-Delay block
Question 8. What causes 'single-phasing' in a 3-phase induction motor,
and what is its effect?
A. Loss of one incoming phase, causing severe current draw on remaining
phases and thermal damage
B. Reversal of two phase leads, causing the motor to spin backward
C. Voltage surge on all three phases, causing overspeed
D. Grounding of the neutral line, causing fuse blow
Question 9. Which sensor type detects metallic objects without physical
contact using high-frequency electromagnetic fields?
A. Capacitive proximity sensor
, B. Inductive proximity sensor
C. Photoelectric retro-reflective sensor
D. Ultrasonic distance sensor
Question 10. When measuring current using a digital multimeter inline
(series), what will happen if the technician connects the leads across a
120V power supply (parallel)?
A. The meter will accurately display line voltage
B. A direct short circuit will occur, blowing the meter internal fuse or
tripping the breaker
C. The circuit load will operate normally
D. The meter resistance will increase automatically
Question 11. What electrical device is designed to protect personnel from
electric shock by detecting current imbalances between hot and neutral
conductors?
A. Ground Fault Circuit Interrupter (GFCI)
B. Thermal-magnetic circuit breaker
C. Surge suppressor
D. Isolation transformer
Question 12. What is the primary purpose of a step-down control
transformer in an industrial motor control center (MCC)?
A. To convert AC voltage to DC voltage for sensors
B. To reduce high line voltage (e.g., 480V) to safer control voltage (e.g.,
120V or 24V) for pushbuttons and coils
C. To regulate motor RPM under heavy load
D. To correct power factor in inductive circuits
--- Domain: Hydraulic & Pneumatic Fluid Power ---