LADWP Electric Station Operator (Electrical
Mechanic/Test Technician) Certification Exam Study
Guide | Complete Practice Questions with Verified
Answers & Detailed Rationales | 2026/2027 Edition
Question 1
Define Voltage.
Answer: An electromotive force or potential difference expressed in volts. Potential to
do work. ✔✔
Rationale: Voltage is the electrical pressure that pushes electrons through a circuit,
representing the potential energy available to do work.
Question 2
Define Direct Current (DC).
Answer: Electric current that flows in only one direction. ✔✔
Rationale: Direct current flows consistently in one direction, typically from negative to
positive terminals.
Question 3
Define Alternating Current (AC).
Answer: A flow of electric charge that regularly reverses its direction. Bidirectional.
✔✔
Rationale: Alternating current periodically reverses direction, typically 60 times per
second in the US power grid.
Question 4
Define Wattage.
Answer: The electrical power consumed by a device. ✔✔
Rationale: Wattage is the rate at which electrical energy is consumed, calculated as
voltage multiplied by current.
pg. 1
,Question 5
Define Coulomb.
Answer: The SI unit of electric charge, equal to the quantity of electricity conveyed in
one second by a current of one ampere. ✔✔
Rationale: One coulomb is the amount of charge transported by a current of one
ampere in one second.
Question 6
1 amp = ? coulomb/sec
Answer: 1 amp = 1 coulomb/sec. ✔✔
Rationale: One ampere equals one coulomb of charge passing a point per second.
Question 7
1 amp = ? electrons
Answer: 1 amp = 6.25 x 10¹⁸ electrons. ✔✔
Rationale: One ampere represents approximately 6.25 x 10¹⁸ electrons passing a point
per second.
Question 8
Define Ohm.
Answer: Unit of electrical resistance. ✔✔
Rationale: The ohm is the standard unit for measuring electrical resistance.
Question 9
Define Ampere (amp).
Answer: Unit that measures the strength of an electric current. ✔✔
Rationale: The ampere is the base unit for measuring electrical current.
Question 10
Define Ammeter.
Answer: A device used to measure current in amperes. ✔✔
Rationale: An ammeter measures current by being connected in series with the circuit.
pg. 2
, Question 11
Define Voltmeter.
Answer: A device used to measure electrical potential or voltage. ✔✔
Rationale: A voltmeter measures voltage by being connected in parallel with the
circuit.
Question 12
Define Wattmeter.
Answer: Measures electric power in watts. ✔✔
Rationale: A wattmeter measures electrical power, calculated as voltage multiplied by
current.
Question 13
Define Megger.
Answer: An instrument used for checking the insulation resistance on motors, feeders,
bus bar systems, grounds, and branch circuit wiring. Read in millions of ohms. ✔✔
Rationale: A Megger applies high voltage to test insulation integrity and resistance.
Question 14
Define Oscilloscope.
Answer: A device used to display the shape of an electrical wave. ✔✔
Rationale: An oscilloscope visualizes voltage waveforms over time for signal analysis.
Question 15
Define Multimeter.
Answer: A measuring instrument for current, voltage, and resistance. ✔✔
Rationale: A multimeter combines multiple measurement functions into one portable
device.
pg. 3
Mechanic/Test Technician) Certification Exam Study
Guide | Complete Practice Questions with Verified
Answers & Detailed Rationales | 2026/2027 Edition
Question 1
Define Voltage.
Answer: An electromotive force or potential difference expressed in volts. Potential to
do work. ✔✔
Rationale: Voltage is the electrical pressure that pushes electrons through a circuit,
representing the potential energy available to do work.
Question 2
Define Direct Current (DC).
Answer: Electric current that flows in only one direction. ✔✔
Rationale: Direct current flows consistently in one direction, typically from negative to
positive terminals.
Question 3
Define Alternating Current (AC).
Answer: A flow of electric charge that regularly reverses its direction. Bidirectional.
✔✔
Rationale: Alternating current periodically reverses direction, typically 60 times per
second in the US power grid.
Question 4
Define Wattage.
Answer: The electrical power consumed by a device. ✔✔
Rationale: Wattage is the rate at which electrical energy is consumed, calculated as
voltage multiplied by current.
pg. 1
,Question 5
Define Coulomb.
Answer: The SI unit of electric charge, equal to the quantity of electricity conveyed in
one second by a current of one ampere. ✔✔
Rationale: One coulomb is the amount of charge transported by a current of one
ampere in one second.
Question 6
1 amp = ? coulomb/sec
Answer: 1 amp = 1 coulomb/sec. ✔✔
Rationale: One ampere equals one coulomb of charge passing a point per second.
Question 7
1 amp = ? electrons
Answer: 1 amp = 6.25 x 10¹⁸ electrons. ✔✔
Rationale: One ampere represents approximately 6.25 x 10¹⁸ electrons passing a point
per second.
Question 8
Define Ohm.
Answer: Unit of electrical resistance. ✔✔
Rationale: The ohm is the standard unit for measuring electrical resistance.
Question 9
Define Ampere (amp).
Answer: Unit that measures the strength of an electric current. ✔✔
Rationale: The ampere is the base unit for measuring electrical current.
Question 10
Define Ammeter.
Answer: A device used to measure current in amperes. ✔✔
Rationale: An ammeter measures current by being connected in series with the circuit.
pg. 2
, Question 11
Define Voltmeter.
Answer: A device used to measure electrical potential or voltage. ✔✔
Rationale: A voltmeter measures voltage by being connected in parallel with the
circuit.
Question 12
Define Wattmeter.
Answer: Measures electric power in watts. ✔✔
Rationale: A wattmeter measures electrical power, calculated as voltage multiplied by
current.
Question 13
Define Megger.
Answer: An instrument used for checking the insulation resistance on motors, feeders,
bus bar systems, grounds, and branch circuit wiring. Read in millions of ohms. ✔✔
Rationale: A Megger applies high voltage to test insulation integrity and resistance.
Question 14
Define Oscilloscope.
Answer: A device used to display the shape of an electrical wave. ✔✔
Rationale: An oscilloscope visualizes voltage waveforms over time for signal analysis.
Question 15
Define Multimeter.
Answer: A measuring instrument for current, voltage, and resistance. ✔✔
Rationale: A multimeter combines multiple measurement functions into one portable
device.
pg. 3
