LADWP ELECTRICAL CRAFT HELPER EXAM
2026 – PRACTICE QUESTIONS, VERIFIED ANSWERS &
DETAILED RATIONALES
, 70 Practice Questions with Verified Answers & Detailed Rationales
The LADWP Electrical Craft Helper (ECH) examination is administered by
the City of Los Angeles Personnel Department for entry-level positions supporting
journey-level electricians. The exam covers electrical fundamentals, safety, tools,
mechanical aptitude, and situational judgment .
SECTION 1: ELECTRICAL FUNDAMENTALS (Questions 1-20)
Q1. What is the unit of measurement for electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Correct Answer: C
, Rationale: Resistance is measured in ohms (Ω), defined by Ohm's Law as V
= I × R. Volts measure electromotive force (voltage), amperes measure current,
and watts measure power .
Q2. The standard frequency of AC power supplied in the United States is:
A) 25 Hz
B) 50 Hz
C) 60 Hz
D) 100 Hz
Correct Answer: C
Rationale: U.S. utility grids operate at 60 hertz (Hz), whereas many other
countries use 50 Hz .
, Q3. Which material is the best conductor of electricity among common
wiring materials?
A) Aluminum
B) Copper
C) Steel
D) PVC
Correct Answer: B
Rationale: Copper has the highest conductivity among common wiring
materials, surpassing aluminum and far exceeding non-conductors like steel or
PVC .
Q4. Which of the following is an example of an insulator?
A) Aluminum
2026 – PRACTICE QUESTIONS, VERIFIED ANSWERS &
DETAILED RATIONALES
, 70 Practice Questions with Verified Answers & Detailed Rationales
The LADWP Electrical Craft Helper (ECH) examination is administered by
the City of Los Angeles Personnel Department for entry-level positions supporting
journey-level electricians. The exam covers electrical fundamentals, safety, tools,
mechanical aptitude, and situational judgment .
SECTION 1: ELECTRICAL FUNDAMENTALS (Questions 1-20)
Q1. What is the unit of measurement for electrical resistance?
A) Volt
B) Ampere
C) Ohm
D) Watt
Correct Answer: C
, Rationale: Resistance is measured in ohms (Ω), defined by Ohm's Law as V
= I × R. Volts measure electromotive force (voltage), amperes measure current,
and watts measure power .
Q2. The standard frequency of AC power supplied in the United States is:
A) 25 Hz
B) 50 Hz
C) 60 Hz
D) 100 Hz
Correct Answer: C
Rationale: U.S. utility grids operate at 60 hertz (Hz), whereas many other
countries use 50 Hz .
, Q3. Which material is the best conductor of electricity among common
wiring materials?
A) Aluminum
B) Copper
C) Steel
D) PVC
Correct Answer: B
Rationale: Copper has the highest conductivity among common wiring
materials, surpassing aluminum and far exceeding non-conductors like steel or
PVC .
Q4. Which of the following is an example of an insulator?
A) Aluminum
