LADWP ELECTRICAL CRAFT HELPER EXAM:
Questions Latest 2026 Update - Verified Solutions with
Detailed Rationales
Secure a top tier position on the Los Angeles Department of Water and
Power civil service hiring roster with this definitive 2026 Electrical Craft
Helper practice exam bank featuring questions. This comprehensive
preparation resource includes verified correct answers and detailed
technical rationales covering basic electrical circuits, tool safety,
mechanical reasoning, and OSHA regulations. It is an indispensable study
tool for aspiring utility workers looking to clear the highly competitive
examination on their first attempt and jumpstart their career.
Question 1
What is the unit of 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, amperes measure current, and watts measure power.
,Question 2
What is the standard frequency of AC power supplied in the United States?
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). This standard frequency was
established during the development of the alternating current system and remains the
North American standard.
Question 3
Which formula correctly represents Ohm's Law?
A) V = I / R
B) V = I × R
C) V = R / I
D) V = P × I
Correct Answer: B
Rationale: Ohm's Law states that voltage (V) equals current (I) multiplied by resistance
(R): V = I × R. This is the fundamental relationship in electrical circuits.
Question 4
A circuit has a voltage of 120 volts and a resistance of 60 ohms. What is the current?
,A) 0.5 A
B) 2 A
C) 60 A
D) 180 A
Correct Answer: B
Rationale: Using Ohm's Law: I = V / R = = 2 amperes.
Question 5
A circuit has a resistance of 30 Ω and current of 4 A. What voltage is required?
A) 7.5 V
B) 26 V
C) 120 V
D) 240 V
Correct Answer: C
Rationale: Using V = I × R, 4 × 30 = 120 volts.
Question 6
What is the total resistance of two 10-ohm resistors connected in series?
A) 5 ohms
B) 10 ohms
C) 20 ohms
D) 100 ohms
Correct Answer: C
, Rationale: In a series circuit, total resistance is the sum of individual resistances: R_total =
R₁ + R₂ = 10 + 10 = 20 ohms.
Question 7
What is the total resistance of two 10-ohm resistors connected in parallel?
A) 5 ohms
B) 10 ohms
C) 15 ohms
D) 20 ohms
Correct Answer: A
Rationale: In a parallel circuit: 1/R_total = 1/R₁ + 1/R₂ = 1/10 + 1/10 = 2/10, so R_total
= 5 ohms.
Question 8
What happens to current in a series circuit when one component fails open?
A) The circuit continues to operate at reduced voltage
B) The circuit remains fully functional
C) Current stops flowing through the entire circuit
D) Current increases in the remaining components
Correct Answer: C
Rationale: In a series circuit, there is only one path for current. An open breaks the single
continuous loop, halting current flow throughout the entire circuit.
Questions Latest 2026 Update - Verified Solutions with
Detailed Rationales
Secure a top tier position on the Los Angeles Department of Water and
Power civil service hiring roster with this definitive 2026 Electrical Craft
Helper practice exam bank featuring questions. This comprehensive
preparation resource includes verified correct answers and detailed
technical rationales covering basic electrical circuits, tool safety,
mechanical reasoning, and OSHA regulations. It is an indispensable study
tool for aspiring utility workers looking to clear the highly competitive
examination on their first attempt and jumpstart their career.
Question 1
What is the unit of 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, amperes measure current, and watts measure power.
,Question 2
What is the standard frequency of AC power supplied in the United States?
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). This standard frequency was
established during the development of the alternating current system and remains the
North American standard.
Question 3
Which formula correctly represents Ohm's Law?
A) V = I / R
B) V = I × R
C) V = R / I
D) V = P × I
Correct Answer: B
Rationale: Ohm's Law states that voltage (V) equals current (I) multiplied by resistance
(R): V = I × R. This is the fundamental relationship in electrical circuits.
Question 4
A circuit has a voltage of 120 volts and a resistance of 60 ohms. What is the current?
,A) 0.5 A
B) 2 A
C) 60 A
D) 180 A
Correct Answer: B
Rationale: Using Ohm's Law: I = V / R = = 2 amperes.
Question 5
A circuit has a resistance of 30 Ω and current of 4 A. What voltage is required?
A) 7.5 V
B) 26 V
C) 120 V
D) 240 V
Correct Answer: C
Rationale: Using V = I × R, 4 × 30 = 120 volts.
Question 6
What is the total resistance of two 10-ohm resistors connected in series?
A) 5 ohms
B) 10 ohms
C) 20 ohms
D) 100 ohms
Correct Answer: C
, Rationale: In a series circuit, total resistance is the sum of individual resistances: R_total =
R₁ + R₂ = 10 + 10 = 20 ohms.
Question 7
What is the total resistance of two 10-ohm resistors connected in parallel?
A) 5 ohms
B) 10 ohms
C) 15 ohms
D) 20 ohms
Correct Answer: A
Rationale: In a parallel circuit: 1/R_total = 1/R₁ + 1/R₂ = 1/10 + 1/10 = 2/10, so R_total
= 5 ohms.
Question 8
What happens to current in a series circuit when one component fails open?
A) The circuit continues to operate at reduced voltage
B) The circuit remains fully functional
C) Current stops flowing through the entire circuit
D) Current increases in the remaining components
Correct Answer: C
Rationale: In a series circuit, there is only one path for current. An open breaks the single
continuous loop, halting current flow throughout the entire circuit.
