LADWP APPRENTICE ELECTRICAL
REPAIRER PRACTICE EXAM WITH
QUESTIONS AND VERIFIED ANSWERS,
PLUS DETAILED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1. Electrical Safety and Lockout/Tagout
Before an Apprentice Electrical Repairer begins troubleshooting a motor
control cabinet that is believed to be de-energized, which procedure
provides the most appropriate protection against unexpected
energization?
A. Turn the disconnect handle to OFF and immediately begin testing
B. Notify nearby employees and place a warning sign on the cabinet
C. Identify all energy sources, disconnect them, apply personal
locks/tags, release stored energy, and verify absence of voltage
D. Remove the control fuse and begin working on the power circuit
Answer: C. Identify all energy sources, disconnect them, apply
personal locks/tags, release stored energy, and verify absence of
voltage
Rationale: Proper lockout/tagout requires control of all hazardous
energy sources, not merely switching a disconnect OFF. The worker
should identify electrical and other stored-energy sources, isolate
them, apply the appropriate lock and tag, discharge or restrain stored
energy, and verify that the circuit is actually de-energized using an
appropriate test instrument.
1
,2. Electrical Measurements
An apprentice measures 480 V between two ungrounded conductors of a
three-phase system. When measuring from each conductor to ground,
the readings are approximately 277 V. What does this most likely
indicate?
A. A 480/277-V three-phase system
B. A 240/120-V single-phase system
C. A 208/120-V system
D. A defective grounding electrode
Answer: A. A 480/277-V three-phase system
Rationale: A typical 480/277-V three-phase, four-wire system has
approximately 480 V line-to-line and approximately 277 V line-to-
neutral or ground under normal conditions. Recognizing standard
system voltages is essential when troubleshooting equipment and
selecting appropriate test instruments and components.
3. Ohmmeter Safety
Why must power normally be removed from a circuit before measuring
resistance with an ohmmeter?
A. Resistance measurements require the circuit to be at full operating
voltage
B. The ohmmeter supplies its own small test voltage and an energized
circuit can damage the instrument or produce incorrect readings
C. Ohmmeters can only measure resistance on DC circuits
D. The resistance of copper disappears when the circuit is energized
Answer: B. The ohmmeter supplies its own small test voltage and an
energized circuit can damage the instrument or produce incorrect
readings
2
,Rationale: An ohmmeter contains an internal source used to pass
current through the circuit under test. An external energized circuit
can interfere with the measurement and potentially damage the meter.
The circuit should therefore be properly isolated before resistance
testing.
4. Three-Phase Motors
A three-phase motor rotates in the opposite direction from what is
required after installation. What is the standard corrective procedure?
A. Increase the motor's overload setting
B. Replace all three phase conductors
C. Interchange any two of the three phase conductors
D. Reverse the equipment grounding conductor
Answer: C. Interchange any two of the three phase conductors
Rationale: Reversing any two phases of a three-phase motor reverses
the phase sequence reaching the motor and therefore reverses motor
rotation. The equipment grounding conductor must never be used for
this purpose, and overload settings should not be altered merely to
correct rotation.
5. Motor Overload Protection
A motor repeatedly trips its overload relay even though the motor is not
mechanically jammed. Which condition should be investigated first?
A. Incorrect overload setting, excessive mechanical load, phase
imbalance, or poor connections
B. Paint color on the motor housing
C. The length of the equipment grounding conductor
D. Whether the motor has a nameplate
3
, Answer: A. Incorrect overload setting, excessive mechanical load,
phase imbalance, or poor connections
Rationale: Repeated overload operation indicates that the motor may
be drawing excessive current or that the protection is improperly
adjusted. Mechanical loading, phase imbalance, low voltage, loose
connections, bearing problems, ventilation restrictions, and incorrect
overload settings are all important diagnostic possibilities.
6. Fuses and Circuit Protection
A fuse is repeatedly opening in a branch circuit. What is the best
troubleshooting approach?
A. Install a larger fuse so the circuit will remain energized
B. Replace the fuse repeatedly until one remains intact
C. Determine why excessive current is occurring before replacing the
fuse with the properly rated device
D. Bypass the fuse temporarily with a conductor
Answer: C. Determine why excessive current is occurring before
replacing the fuse with the properly rated device
Rationale: A fuse opens because current has exceeded its permitted
value for a sufficient period. Replacing it with a larger fuse or
bypassing it can defeat the circuit's intended protection and create a
fire or equipment hazard. The underlying short circuit, overload,
ground fault, or equipment failure must be identified.
7. Transformer Operation
A transformer has a primary winding connected to a higher voltage and
a secondary winding providing a lower voltage. Which principle
explains this voltage transformation?
4
REPAIRER PRACTICE EXAM WITH
QUESTIONS AND VERIFIED ANSWERS,
PLUS DETAILED RATIONALES/EXPERT
VERIFIED FOR GUARANTEED PASS
2026/LATEST UPDATE/INSTANT
DOWNLOAD PDF
1. Electrical Safety and Lockout/Tagout
Before an Apprentice Electrical Repairer begins troubleshooting a motor
control cabinet that is believed to be de-energized, which procedure
provides the most appropriate protection against unexpected
energization?
A. Turn the disconnect handle to OFF and immediately begin testing
B. Notify nearby employees and place a warning sign on the cabinet
C. Identify all energy sources, disconnect them, apply personal
locks/tags, release stored energy, and verify absence of voltage
D. Remove the control fuse and begin working on the power circuit
Answer: C. Identify all energy sources, disconnect them, apply
personal locks/tags, release stored energy, and verify absence of
voltage
Rationale: Proper lockout/tagout requires control of all hazardous
energy sources, not merely switching a disconnect OFF. The worker
should identify electrical and other stored-energy sources, isolate
them, apply the appropriate lock and tag, discharge or restrain stored
energy, and verify that the circuit is actually de-energized using an
appropriate test instrument.
1
,2. Electrical Measurements
An apprentice measures 480 V between two ungrounded conductors of a
three-phase system. When measuring from each conductor to ground,
the readings are approximately 277 V. What does this most likely
indicate?
A. A 480/277-V three-phase system
B. A 240/120-V single-phase system
C. A 208/120-V system
D. A defective grounding electrode
Answer: A. A 480/277-V three-phase system
Rationale: A typical 480/277-V three-phase, four-wire system has
approximately 480 V line-to-line and approximately 277 V line-to-
neutral or ground under normal conditions. Recognizing standard
system voltages is essential when troubleshooting equipment and
selecting appropriate test instruments and components.
3. Ohmmeter Safety
Why must power normally be removed from a circuit before measuring
resistance with an ohmmeter?
A. Resistance measurements require the circuit to be at full operating
voltage
B. The ohmmeter supplies its own small test voltage and an energized
circuit can damage the instrument or produce incorrect readings
C. Ohmmeters can only measure resistance on DC circuits
D. The resistance of copper disappears when the circuit is energized
Answer: B. The ohmmeter supplies its own small test voltage and an
energized circuit can damage the instrument or produce incorrect
readings
2
,Rationale: An ohmmeter contains an internal source used to pass
current through the circuit under test. An external energized circuit
can interfere with the measurement and potentially damage the meter.
The circuit should therefore be properly isolated before resistance
testing.
4. Three-Phase Motors
A three-phase motor rotates in the opposite direction from what is
required after installation. What is the standard corrective procedure?
A. Increase the motor's overload setting
B. Replace all three phase conductors
C. Interchange any two of the three phase conductors
D. Reverse the equipment grounding conductor
Answer: C. Interchange any two of the three phase conductors
Rationale: Reversing any two phases of a three-phase motor reverses
the phase sequence reaching the motor and therefore reverses motor
rotation. The equipment grounding conductor must never be used for
this purpose, and overload settings should not be altered merely to
correct rotation.
5. Motor Overload Protection
A motor repeatedly trips its overload relay even though the motor is not
mechanically jammed. Which condition should be investigated first?
A. Incorrect overload setting, excessive mechanical load, phase
imbalance, or poor connections
B. Paint color on the motor housing
C. The length of the equipment grounding conductor
D. Whether the motor has a nameplate
3
, Answer: A. Incorrect overload setting, excessive mechanical load,
phase imbalance, or poor connections
Rationale: Repeated overload operation indicates that the motor may
be drawing excessive current or that the protection is improperly
adjusted. Mechanical loading, phase imbalance, low voltage, loose
connections, bearing problems, ventilation restrictions, and incorrect
overload settings are all important diagnostic possibilities.
6. Fuses and Circuit Protection
A fuse is repeatedly opening in a branch circuit. What is the best
troubleshooting approach?
A. Install a larger fuse so the circuit will remain energized
B. Replace the fuse repeatedly until one remains intact
C. Determine why excessive current is occurring before replacing the
fuse with the properly rated device
D. Bypass the fuse temporarily with a conductor
Answer: C. Determine why excessive current is occurring before
replacing the fuse with the properly rated device
Rationale: A fuse opens because current has exceeded its permitted
value for a sufficient period. Replacing it with a larger fuse or
bypassing it can defeat the circuit's intended protection and create a
fire or equipment hazard. The underlying short circuit, overload,
ground fault, or equipment failure must be identified.
7. Transformer Operation
A transformer has a primary winding connected to a higher voltage and
a secondary winding providing a lower voltage. Which principle
explains this voltage transformation?
4
