LADWP ELECTRICAL MECHANIC–TEST TECHNICIAN EXAM QUESTIONS AND ANSWERS ALREADY GRADED
A+| 100% VERIFIED SOLUTIONS
Core Domains
Electrical Theory and Fundamentals (AC/DC Circuits, Ohm's Law, Kirchhoff's Laws)
Transformers and Electrical Machines
Station Equipment and Control Systems
Testing and Diagnostic Instrumentation
Protective Relaying and Circuit Breakers
Safety, Codes, and Regulatory Compliance (LOTO, NFPA 70E, Cal/OSHA)
Electronics and Digital Logic
Mechanical Aptitude and Rigging
Power Systems and Distribution
Mathematics and Practical Calculations
Introduction
This comprehensive examination is designed to assess the technical knowledge, practical skills, and critical
decision-making abilities required for the LADWP Electrical Mechanic–Test Technician role. The test evaluates
proficiency in electrical theory, transformer and motor principles, protective relaying, testing instrumentation, and
safety protocols essential for maintaining and troubleshooting high-voltage substation equipment. Candidates will
,be challenged with multiple-choice and scenario-based questions that mirror real-world utility operations,
emphasizing the application of electrical principles, diagnostic reasoning, and compliance with LADWP standards
and safety regulations. This assessment serves as a vital tool for identifying strengths and areas for focused study
prior to the certification examination.
SECTION ONE: QUESTIONS 1–100
1. A 120V circuit draws 15A. What is the resistance of the circuit?
A. 4Ω
B. 8Ω
C. 12Ω
D. 18Ω
🟢B
🔴 RATIONALE: Ohm's Law states R = V / I. Therefore, R = 120V / 15A = 8Ω. This is a fundamental calculation
for troubleshooting electrical circuits.
2. In a purely inductive AC circuit, how does current relate to voltage?
,A. Current leads voltage by 90°
B. Current lags voltage by 90°
C. In phase
D. 180° out of phase
🟢B
🔴 RATIONALE: In a purely inductive circuit, the inductor opposes changes in current, causing the current to lag
the voltage by 90 degrees. This is a fundamental concept of AC circuit theory.
3. In a balanced three-phase wye (Y) system, what is the relationship between line voltage (VL) and phase
voltage (Vph)?
A. VL = Vph
B. VL = √3 × Vph
C. VL = 3 × Vph
D. VL = Vph / √3
🟢B
🔴 RATIONALE: In a wye configuration, the line voltage is 1.732 times the phase voltage due to the 120-degree
phase shift between phases. VL = √3 × Vph.
, 4. A transformer with a turns ratio of 10:1 (Primary:Secondary) has 2400V AC applied to the primary. What is
the secondary voltage?
A. 24,000V
B. 240V
C. 2,400V
D. 120V
🟢B
🔴 RATIONALE: Using the transformer turns ratio formula: Vs = Vp × (Ns / Np) = 2400 × (1/10) = 240V.
5. What is the primary function of a capacitor in an AC circuit?
A. To store energy in a magnetic field
B. To oppose changes in voltage
C. To oppose changes in current
D. To convert AC to DC
🟢B
🔴 RATIONALE: Capacitors resist changes in voltage by storing energy in an electric field. This property is
fundamental to their behavior in AC circuits.
A+| 100% VERIFIED SOLUTIONS
Core Domains
Electrical Theory and Fundamentals (AC/DC Circuits, Ohm's Law, Kirchhoff's Laws)
Transformers and Electrical Machines
Station Equipment and Control Systems
Testing and Diagnostic Instrumentation
Protective Relaying and Circuit Breakers
Safety, Codes, and Regulatory Compliance (LOTO, NFPA 70E, Cal/OSHA)
Electronics and Digital Logic
Mechanical Aptitude and Rigging
Power Systems and Distribution
Mathematics and Practical Calculations
Introduction
This comprehensive examination is designed to assess the technical knowledge, practical skills, and critical
decision-making abilities required for the LADWP Electrical Mechanic–Test Technician role. The test evaluates
proficiency in electrical theory, transformer and motor principles, protective relaying, testing instrumentation, and
safety protocols essential for maintaining and troubleshooting high-voltage substation equipment. Candidates will
,be challenged with multiple-choice and scenario-based questions that mirror real-world utility operations,
emphasizing the application of electrical principles, diagnostic reasoning, and compliance with LADWP standards
and safety regulations. This assessment serves as a vital tool for identifying strengths and areas for focused study
prior to the certification examination.
SECTION ONE: QUESTIONS 1–100
1. A 120V circuit draws 15A. What is the resistance of the circuit?
A. 4Ω
B. 8Ω
C. 12Ω
D. 18Ω
🟢B
🔴 RATIONALE: Ohm's Law states R = V / I. Therefore, R = 120V / 15A = 8Ω. This is a fundamental calculation
for troubleshooting electrical circuits.
2. In a purely inductive AC circuit, how does current relate to voltage?
,A. Current leads voltage by 90°
B. Current lags voltage by 90°
C. In phase
D. 180° out of phase
🟢B
🔴 RATIONALE: In a purely inductive circuit, the inductor opposes changes in current, causing the current to lag
the voltage by 90 degrees. This is a fundamental concept of AC circuit theory.
3. In a balanced three-phase wye (Y) system, what is the relationship between line voltage (VL) and phase
voltage (Vph)?
A. VL = Vph
B. VL = √3 × Vph
C. VL = 3 × Vph
D. VL = Vph / √3
🟢B
🔴 RATIONALE: In a wye configuration, the line voltage is 1.732 times the phase voltage due to the 120-degree
phase shift between phases. VL = √3 × Vph.
, 4. A transformer with a turns ratio of 10:1 (Primary:Secondary) has 2400V AC applied to the primary. What is
the secondary voltage?
A. 24,000V
B. 240V
C. 2,400V
D. 120V
🟢B
🔴 RATIONALE: Using the transformer turns ratio formula: Vs = Vp × (Ns / Np) = 2400 × (1/10) = 240V.
5. What is the primary function of a capacitor in an AC circuit?
A. To store energy in a magnetic field
B. To oppose changes in voltage
C. To oppose changes in current
D. To convert AC to DC
🟢B
🔴 RATIONALE: Capacitors resist changes in voltage by storing energy in an electric field. This property is
fundamental to their behavior in AC circuits.
