LADWP Electric Distribution Mechanic Trainee Exam
Questions and Answers (Study Guide)
Table of Contents
1. Section 1: Electrical Theory and Fundamentals (Questions 1–65)
2. Section 2: AC/DC Circuits, Voltage, Current, Resistance, and Ohm's Law (Questions 66–
130)
3. Section 3: Transformers, Distribution Systems, Conductors, and Power Equipment
(Questions 131–195)
4. Section 4: Overhead Distribution Lines, Poles, Crossarms, Guys, and Line Hardware
(Questions 196–250)
5. Section 5: Underground Distribution, Cables, Splicing, Terminations, and Faults
(Questions 251–310)
6. Section 6: Electrical Tools, Hand Tools, Power Tools, and Equipment Identification
(Questions 311–345)
7. Section 7: Electrical and Mechanical Principles, Fasteners, Torque, and Basic Mechanics
(Questions 346–370)
8. Section 8: Electrical Safety, Energized Work, PPE, Grounding, and Lockout/Tagout
(Questions 371–400)
SECTION 1: ELECTRICAL THEORY AND FUNDAMENTALS
(Questions 1–65)
,1. A circuit has a voltage of 240 V and a resistance of 30 Ω. What is the current
flowing through the circuit?
A) 8 A
B) 0.125 A
C) 7200 A
D) 270 A
Answer: A) 8 A
Rationale: Ohm's Law states: I = V / R. Therefore: I = 240 V / 30 Ω = 8 A.
2. What is the definition of "Amps"?
A) Electric potential between two points
B) The flow of electrical current
C) The resistance to electrical flow
D) The power consumed by a load
Rationale: Amperes (amps) measure the rate of electrical current flow. A common analogy
is "gallons per minute" (GPM) for water flow.
3. What is the definition of "Volts"?
A) Current flow
B) Electric potential between two points
C) Relationship between watts and resistance
,D) Power consumption
Rationale: Voltage (volts) is the electrical potential difference between two points. A
common analogy is "pounds per square inch" (PSI) for water pressure.
4. What is the definition of "Watts"?
A) Amps × Volts
B) Volts / Amps
C) Resistance × Current
D) Power factor × Efficiency
Rationale: Power (watts) is calculated as Amps × Volts. This is the fundamental power
formula for electrical circuits.
5. What is the relationship between Watts, Amps, and Volts?
A) Watts = Amps / Volts
B) Watts = Amps × Volts
C) Watts = Volts / Amps
D) Watts = Amps + Volts
Rationale: Power in watts is the product of current in amperes and voltage in volts: P = I ×
V.
6. A distribution mechanic measures 120 volts across a load drawing 10 amperes
during normal operation. Which electrical relationship correctly determines the
load's power consumption?
, A) 12 watts
B) 1,200 watts
C) 120 watts
D) 1,200 amperes
Rationale: Electrical power in a resistive load is calculated using P = VI. Multiplying 120
volts by 10 amperes produces 1,200 watts.
7. When two resistors are connected in series, which characteristic most directly
distinguishes the series arrangement from a parallel arrangement during circuit
analysis?
A) Voltage remains identical across each resistor
B) Branch current divides between components
C) Total resistance decreases below each resistor
D) The same current passes through each resistor
Rationale: In a series circuit, there is only one current path, so the same current flows
through every component. Voltage divides according to resistance.
8. What is the resistance of a circuit that draws 5 amps at 120 volts?
A) 24 Ω
B) 600 Ω
C) 0.041 Ω
D) 120 Ω
Rationale: Ohm's Law: R = V / I = 120 V / 5 A = 24 Ω.
Questions and Answers (Study Guide)
Table of Contents
1. Section 1: Electrical Theory and Fundamentals (Questions 1–65)
2. Section 2: AC/DC Circuits, Voltage, Current, Resistance, and Ohm's Law (Questions 66–
130)
3. Section 3: Transformers, Distribution Systems, Conductors, and Power Equipment
(Questions 131–195)
4. Section 4: Overhead Distribution Lines, Poles, Crossarms, Guys, and Line Hardware
(Questions 196–250)
5. Section 5: Underground Distribution, Cables, Splicing, Terminations, and Faults
(Questions 251–310)
6. Section 6: Electrical Tools, Hand Tools, Power Tools, and Equipment Identification
(Questions 311–345)
7. Section 7: Electrical and Mechanical Principles, Fasteners, Torque, and Basic Mechanics
(Questions 346–370)
8. Section 8: Electrical Safety, Energized Work, PPE, Grounding, and Lockout/Tagout
(Questions 371–400)
SECTION 1: ELECTRICAL THEORY AND FUNDAMENTALS
(Questions 1–65)
,1. A circuit has a voltage of 240 V and a resistance of 30 Ω. What is the current
flowing through the circuit?
A) 8 A
B) 0.125 A
C) 7200 A
D) 270 A
Answer: A) 8 A
Rationale: Ohm's Law states: I = V / R. Therefore: I = 240 V / 30 Ω = 8 A.
2. What is the definition of "Amps"?
A) Electric potential between two points
B) The flow of electrical current
C) The resistance to electrical flow
D) The power consumed by a load
Rationale: Amperes (amps) measure the rate of electrical current flow. A common analogy
is "gallons per minute" (GPM) for water flow.
3. What is the definition of "Volts"?
A) Current flow
B) Electric potential between two points
C) Relationship between watts and resistance
,D) Power consumption
Rationale: Voltage (volts) is the electrical potential difference between two points. A
common analogy is "pounds per square inch" (PSI) for water pressure.
4. What is the definition of "Watts"?
A) Amps × Volts
B) Volts / Amps
C) Resistance × Current
D) Power factor × Efficiency
Rationale: Power (watts) is calculated as Amps × Volts. This is the fundamental power
formula for electrical circuits.
5. What is the relationship between Watts, Amps, and Volts?
A) Watts = Amps / Volts
B) Watts = Amps × Volts
C) Watts = Volts / Amps
D) Watts = Amps + Volts
Rationale: Power in watts is the product of current in amperes and voltage in volts: P = I ×
V.
6. A distribution mechanic measures 120 volts across a load drawing 10 amperes
during normal operation. Which electrical relationship correctly determines the
load's power consumption?
, A) 12 watts
B) 1,200 watts
C) 120 watts
D) 1,200 amperes
Rationale: Electrical power in a resistive load is calculated using P = VI. Multiplying 120
volts by 10 amperes produces 1,200 watts.
7. When two resistors are connected in series, which characteristic most directly
distinguishes the series arrangement from a parallel arrangement during circuit
analysis?
A) Voltage remains identical across each resistor
B) Branch current divides between components
C) Total resistance decreases below each resistor
D) The same current passes through each resistor
Rationale: In a series circuit, there is only one current path, so the same current flows
through every component. Voltage divides according to resistance.
8. What is the resistance of a circuit that draws 5 amps at 120 volts?
A) 24 Ω
B) 600 Ω
C) 0.041 Ω
D) 120 Ω
Rationale: Ohm's Law: R = V / I = 120 V / 5 A = 24 Ω.
