LADWP Electrical Craft Helper Exam – EXAM PRACTICE
QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALE 2026 Q&A | INSTANT DOWNLOAD PDF
Questions 1–25
1. What is the primary purpose of a circuit breaker in an electrical circuit?
A) To interrupt current when an unsafe condition such as excessive current occurs
B) To increase the voltage supplied to a load
C) To measure resistance continuously
D) To convert AC power into mechanical energy
Correct Answer: A) To interrupt current when an unsafe condition such as excessive current occurs
Rationale: A circuit breaker is designed to open a circuit when current exceeds a safe level, protecting
conductors and equipment from damage. Unlike a transformer, it does not change voltage, and
unlike a meter, it does not primarily measure electrical quantities. Proper operation of protective
devices is an important electrical-safety principle.
2. Which instrument is most appropriate for measuring voltage between two points in a circuit?
A) Ammeter
B) Voltmeter
C) Ohmmeter
D) Megger only
Correct Answer: B) Voltmeter
Rationale: A voltmeter measures the potential difference between two points and is connected across
the portion of the circuit being tested. An ammeter measures current, while an ohmmeter measures
resistance under appropriate conditions. Electrical helpers must understand the purpose of test
instruments before assisting with inspection, troubleshooting, or maintenance work.
3. Before using a portable power tool, what should a worker do first?
A) Increase the tool's operating speed
B) Remove its protective guard
C) Inspect the tool, cord, plug, and safety features for defects
D) Test it by intentionally overloading it
Correct Answer: C) Inspect the tool, cord, plug, and safety features for defects
Rationale: Inspection before use helps identify damaged cords, plugs, guards, switches, or other
conditions that could create a hazard. Removing guards or intentionally overloading equipment is
unsafe. Electrical craft helpers are expected to use tools properly and safely, making pre-use
inspection an important routine.
,4. A worker needs to determine whether two points in a de-energized circuit have continuity.
Which instrument is most appropriate?
A) Tachometer
B) Ammeter
C) Voltmeter
D) Continuity tester or ohmmeter
Correct Answer: D) Continuity tester or ohmmeter
Rationale: A continuity tester or ohmmeter can determine whether an electrically conductive path
exists in a properly isolated, de-energized circuit. Voltage-testing equipment serves a different
purpose. Before using resistance or continuity functions, the worker must ensure the circuit is
appropriately de-energized and isolated.
5. Which unit is commonly used to express electrical resistance?
A) Ohm
B) Volt
C) Ampere
D) Watt
Correct Answer: A) Ohm
Rationale: The ohm is the SI unit of electrical resistance. The volt measures electrical potential
difference, the ampere measures current, and the watt measures power. Understanding these
fundamental units helps an electrical helper interpret measurements and communicate accurately
with journey-level workers.
6. What does an ammeter measure?
A) Resistance
B) Current
C) Voltage
D) Frequency
Correct Answer: B) Current
Rationale: An ammeter measures electrical current, expressed in amperes. It is generally connected in
series with the portion of a circuit being measured, although modern multimeters may use different
configurations depending on their design. Correct meter selection and connection are essential for
safe electrical testing.
7. A 120-volt load draws 5 amperes. Using P = V × I, what is its power?
A) 24 W
B) 125 W
C) 600 W
D) 625 W
, Correct Answer: C) 600 W
Rationale: Electrical power can be calculated by multiplying voltage by current. Here, 120 volts
multiplied by 5 amperes equals 600 watts. This basic calculation is useful when evaluating electrical
loads and understanding the relationship among voltage, current, and power.
8. Which tool is specifically designed to tighten or loosen a hexagonal fastener?
A) Hacksaw
B) Fish tape
C) Wire brush
D) Wrench
Correct Answer: D) Wrench
Rationale: A wrench is designed to grip and turn nuts, bolts, and other appropriate fasteners.
Selecting the correct tool reduces the likelihood of damaging the fastener or injuring the worker.
Electrical helpers should be able to identify tools and determine which equipment is appropriate for a
particular job.
9. What is the safest general approach when a power tool has a damaged electrical cord?
A) Remove it from service and report the defect
B) Wrap the cord with any available material and continue working
C) Use it only for short periods
D) Operate it while standing on an insulating box
Correct Answer: A) Remove it from service and report the defect
Rationale: A damaged electrical cord can expose workers to shock, short-circuit, or fire hazards.
Improvised repairs should not substitute for proper inspection and authorized repair. Removing
defective equipment from service helps prevent an unsafe tool from being used by the worker or
another employee.
10. Which device is primarily intended to protect people from certain electrical shock hazards
caused by leakage current?
A) Transformer
B) Ground-fault circuit interrupter
C) Fuse holder
D) Junction box
Correct Answer: B) Ground-fault circuit interrupter
Rationale: A ground-fault circuit interrupter, or GFCI, is designed to rapidly interrupt power when it
detects a potentially dangerous imbalance associated with current leakage. It provides a different
protective function from ordinary overcurrent protection. Workers should understand that electrical
protective devices serve specific purposes.
QUESTIONS AND CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALE 2026 Q&A | INSTANT DOWNLOAD PDF
Questions 1–25
1. What is the primary purpose of a circuit breaker in an electrical circuit?
A) To interrupt current when an unsafe condition such as excessive current occurs
B) To increase the voltage supplied to a load
C) To measure resistance continuously
D) To convert AC power into mechanical energy
Correct Answer: A) To interrupt current when an unsafe condition such as excessive current occurs
Rationale: A circuit breaker is designed to open a circuit when current exceeds a safe level, protecting
conductors and equipment from damage. Unlike a transformer, it does not change voltage, and
unlike a meter, it does not primarily measure electrical quantities. Proper operation of protective
devices is an important electrical-safety principle.
2. Which instrument is most appropriate for measuring voltage between two points in a circuit?
A) Ammeter
B) Voltmeter
C) Ohmmeter
D) Megger only
Correct Answer: B) Voltmeter
Rationale: A voltmeter measures the potential difference between two points and is connected across
the portion of the circuit being tested. An ammeter measures current, while an ohmmeter measures
resistance under appropriate conditions. Electrical helpers must understand the purpose of test
instruments before assisting with inspection, troubleshooting, or maintenance work.
3. Before using a portable power tool, what should a worker do first?
A) Increase the tool's operating speed
B) Remove its protective guard
C) Inspect the tool, cord, plug, and safety features for defects
D) Test it by intentionally overloading it
Correct Answer: C) Inspect the tool, cord, plug, and safety features for defects
Rationale: Inspection before use helps identify damaged cords, plugs, guards, switches, or other
conditions that could create a hazard. Removing guards or intentionally overloading equipment is
unsafe. Electrical craft helpers are expected to use tools properly and safely, making pre-use
inspection an important routine.
,4. A worker needs to determine whether two points in a de-energized circuit have continuity.
Which instrument is most appropriate?
A) Tachometer
B) Ammeter
C) Voltmeter
D) Continuity tester or ohmmeter
Correct Answer: D) Continuity tester or ohmmeter
Rationale: A continuity tester or ohmmeter can determine whether an electrically conductive path
exists in a properly isolated, de-energized circuit. Voltage-testing equipment serves a different
purpose. Before using resistance or continuity functions, the worker must ensure the circuit is
appropriately de-energized and isolated.
5. Which unit is commonly used to express electrical resistance?
A) Ohm
B) Volt
C) Ampere
D) Watt
Correct Answer: A) Ohm
Rationale: The ohm is the SI unit of electrical resistance. The volt measures electrical potential
difference, the ampere measures current, and the watt measures power. Understanding these
fundamental units helps an electrical helper interpret measurements and communicate accurately
with journey-level workers.
6. What does an ammeter measure?
A) Resistance
B) Current
C) Voltage
D) Frequency
Correct Answer: B) Current
Rationale: An ammeter measures electrical current, expressed in amperes. It is generally connected in
series with the portion of a circuit being measured, although modern multimeters may use different
configurations depending on their design. Correct meter selection and connection are essential for
safe electrical testing.
7. A 120-volt load draws 5 amperes. Using P = V × I, what is its power?
A) 24 W
B) 125 W
C) 600 W
D) 625 W
, Correct Answer: C) 600 W
Rationale: Electrical power can be calculated by multiplying voltage by current. Here, 120 volts
multiplied by 5 amperes equals 600 watts. This basic calculation is useful when evaluating electrical
loads and understanding the relationship among voltage, current, and power.
8. Which tool is specifically designed to tighten or loosen a hexagonal fastener?
A) Hacksaw
B) Fish tape
C) Wire brush
D) Wrench
Correct Answer: D) Wrench
Rationale: A wrench is designed to grip and turn nuts, bolts, and other appropriate fasteners.
Selecting the correct tool reduces the likelihood of damaging the fastener or injuring the worker.
Electrical helpers should be able to identify tools and determine which equipment is appropriate for a
particular job.
9. What is the safest general approach when a power tool has a damaged electrical cord?
A) Remove it from service and report the defect
B) Wrap the cord with any available material and continue working
C) Use it only for short periods
D) Operate it while standing on an insulating box
Correct Answer: A) Remove it from service and report the defect
Rationale: A damaged electrical cord can expose workers to shock, short-circuit, or fire hazards.
Improvised repairs should not substitute for proper inspection and authorized repair. Removing
defective equipment from service helps prevent an unsafe tool from being used by the worker or
another employee.
10. Which device is primarily intended to protect people from certain electrical shock hazards
caused by leakage current?
A) Transformer
B) Ground-fault circuit interrupter
C) Fuse holder
D) Junction box
Correct Answer: B) Ground-fault circuit interrupter
Rationale: A ground-fault circuit interrupter, or GFCI, is designed to rapidly interrupt power when it
detects a potentially dangerous imbalance associated with current leakage. It provides a different
protective function from ordinary overcurrent protection. Workers should understand that electrical
protective devices serve specific purposes.
