LADWP Electric Station Operator Exam
2025/2026 Edition | Circuit Breakers,
Disconnects, Transformers | Verified Questions
with Passed Answers
1. One of the primary tasks of the Electric Station Operator is the __________ of high
voltage circuits.
A) grounding
B) switching
C) isolating
D) testing
Correct Answer: B) switching
Rationale: Electric Station Operators are primarily responsible for the switching of
high-voltage circuits to control the flow of electricity.
2. Electrical current may flow across the contacts of ____ to ____ electrical switches
before it reaches the consumer.
A) 10 to 20
B) 25 to 75
C) 50 to 100
D) 100 to 200
Correct Answer: C) 50 to 100
Rationale: In a power distribution system, current may pass through 50 to 100
switches between the generator and the end consumer.
,3. The __________ operation of these electrical switches can pose a serious hazard to
personnel, can cause destruction of expensive power system equipment, and can
cause unnecessary interruption of electrical service to consumers.
A) routine
B) automatic
C) emergency
D) improper
Correct Answer: D) improper
Rationale: Improper operation of switches is extremely dangerous, leading to
safety hazards, equipment damage, and service interruptions.
4. Electrical __________ are installed in the path from the generator to the consumer
to provide reliability, flexibility, and safeguards for the electrical power system.
A) breakers
B) switches
C) relays
D) fuses
Correct Answer: B) switches
Rationale: Switches are strategically placed throughout the power system to
ensure reliability, provide operational flexibility, and protect the system.
5. Operators use electrical switches to perform routine, automatic, and ____________
switching operations on the electrical system.
A) manual
B) emergency
C) scheduled
D) preventive
Correct Answer: B) emergency
, Rationale: Operators handle routine, automatic, and emergency switching to
manage the electrical system under various conditions.
6. ___________ switching is for maintenance, construction, cleaning, testing, etc.
A) Routine
B) Automatic
C) Emergency
D) Manual
Correct Answer: A) Routine
Rationale: Routine switching is performed for scheduled activities like
maintenance and testing.
7. ___________ switching operations include automatic reclosers (ARs), Voltage
Pickup Unit (VPUs), and Automatic Transfer Switching (ATSs).
A) Routine
B) Manual
C) Automatic
D) Emergency
Correct Answer: C) Automatic
Rationale: Automatic switching operations are performed by devices like
reclosers and transfer switches without direct human intervention.
8. ___________ switching operations include isolate trouble, restoration, 4.8kV
Ground Search, etc.
A) Routine
B) Automatic
C) Manual
D) Emergency
Correct Answer: D) Emergency
, Rationale: Emergency switching is performed in response to faults or outages to
isolate problems and restore power.
9. Some of the materials used in __________ that have sufficient dielectric strength
for interrupting power system current values are: Insulating oils, pressurized inert
gasses, Sulfur Hexafluoride gas, and Vacuum chambers.
A) Disconnects
B) Circuit Breakers
C) Transformers
D) Busbars
Correct Answer: B) Circuit Breakers
Rationale: Circuit breakers use various dielectric media like oil, SF6 gas, and
vacuum to extinguish arcs and interrupt current.
10. ___________ and moisture in particular are two elements that can destroy the
interrupting capabilities of a chosen dielectric medium.
A) Heat
B) Dirt
C) Oxygen
D) Cold
Correct Answer: B) Dirt
Rationale: Contaminants like dirt and moisture can severely degrade the
dielectric strength of the insulating medium in circuit breakers.
11. Severe contamination of a dielectric medium can cause CBs to __________ by
allowing an arc to be sustained between the open contacts or the contacts and the
grounded tank(s) or housing of the CB.
A) fail
B) trip
C) explode
2025/2026 Edition | Circuit Breakers,
Disconnects, Transformers | Verified Questions
with Passed Answers
1. One of the primary tasks of the Electric Station Operator is the __________ of high
voltage circuits.
A) grounding
B) switching
C) isolating
D) testing
Correct Answer: B) switching
Rationale: Electric Station Operators are primarily responsible for the switching of
high-voltage circuits to control the flow of electricity.
2. Electrical current may flow across the contacts of ____ to ____ electrical switches
before it reaches the consumer.
A) 10 to 20
B) 25 to 75
C) 50 to 100
D) 100 to 200
Correct Answer: C) 50 to 100
Rationale: In a power distribution system, current may pass through 50 to 100
switches between the generator and the end consumer.
,3. The __________ operation of these electrical switches can pose a serious hazard to
personnel, can cause destruction of expensive power system equipment, and can
cause unnecessary interruption of electrical service to consumers.
A) routine
B) automatic
C) emergency
D) improper
Correct Answer: D) improper
Rationale: Improper operation of switches is extremely dangerous, leading to
safety hazards, equipment damage, and service interruptions.
4. Electrical __________ are installed in the path from the generator to the consumer
to provide reliability, flexibility, and safeguards for the electrical power system.
A) breakers
B) switches
C) relays
D) fuses
Correct Answer: B) switches
Rationale: Switches are strategically placed throughout the power system to
ensure reliability, provide operational flexibility, and protect the system.
5. Operators use electrical switches to perform routine, automatic, and ____________
switching operations on the electrical system.
A) manual
B) emergency
C) scheduled
D) preventive
Correct Answer: B) emergency
, Rationale: Operators handle routine, automatic, and emergency switching to
manage the electrical system under various conditions.
6. ___________ switching is for maintenance, construction, cleaning, testing, etc.
A) Routine
B) Automatic
C) Emergency
D) Manual
Correct Answer: A) Routine
Rationale: Routine switching is performed for scheduled activities like
maintenance and testing.
7. ___________ switching operations include automatic reclosers (ARs), Voltage
Pickup Unit (VPUs), and Automatic Transfer Switching (ATSs).
A) Routine
B) Manual
C) Automatic
D) Emergency
Correct Answer: C) Automatic
Rationale: Automatic switching operations are performed by devices like
reclosers and transfer switches without direct human intervention.
8. ___________ switching operations include isolate trouble, restoration, 4.8kV
Ground Search, etc.
A) Routine
B) Automatic
C) Manual
D) Emergency
Correct Answer: D) Emergency
, Rationale: Emergency switching is performed in response to faults or outages to
isolate problems and restore power.
9. Some of the materials used in __________ that have sufficient dielectric strength
for interrupting power system current values are: Insulating oils, pressurized inert
gasses, Sulfur Hexafluoride gas, and Vacuum chambers.
A) Disconnects
B) Circuit Breakers
C) Transformers
D) Busbars
Correct Answer: B) Circuit Breakers
Rationale: Circuit breakers use various dielectric media like oil, SF6 gas, and
vacuum to extinguish arcs and interrupt current.
10. ___________ and moisture in particular are two elements that can destroy the
interrupting capabilities of a chosen dielectric medium.
A) Heat
B) Dirt
C) Oxygen
D) Cold
Correct Answer: B) Dirt
Rationale: Contaminants like dirt and moisture can severely degrade the
dielectric strength of the insulating medium in circuit breakers.
11. Severe contamination of a dielectric medium can cause CBs to __________ by
allowing an arc to be sustained between the open contacts or the contacts and the
grounded tank(s) or housing of the CB.
A) fail
B) trip
C) explode
