LADWP Electric Station Operator Exam Prep
2025/2026 | 100% Verified Study Guide with Correct
Questions & Answers
Dielectric - ANSWER The ability of a substance to prevent the flow of electrical current is
described as its __________ strength.
Conductors - ANSWER __________ of electricity have no dielectric strength, as they allow
current to flow in a circuit.
Air - ANSWER __________, which has a relatively high dielectric strength, is used as the
dielectric medium in many low voltage applications where current values are also low. A
common example is the light switch found in homes, etc.
Circuit Breakers - ANSWER Some of the materials used in __________that have sufficient
dielectric strength of for interrupting power system current values are: Insulating oils,
pressurized inert gasses, Sulfur Hexafluoride gas, and Vacuum chambers.
,Dirt - ANSWER ___________ and moisture in particular are two elements that can destroy
the interrupting capabilities of a chosen dielectric medium.
explode - ANSWER 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.
Bushings - ANSWER __________ are usually made of insulating porcelain.
Nonconductive - ANSWER Portions of the mechanical linkages connected to movable
contacts must be constructed of __________ materials to prevent the electrical components of
the contacts and conductors from energizing the components of the CB such as the tank, controls,
etc.
0.2 - ANSWER The operating time, from fully open to fully closed, in many large CBs, is
often less than __________ seconds.
linkage - ANSWER Failure of the mechanical __________ (sometimes referred to as the
actuating arm or lever) can cause serious damage to the circuit breaker or may cause normally
non-energized portions of the CB to become energized.
, Control - ANSWER __________ circuits use auxiliary devices that direct the operation of
the CB.
Semaphore - ANSWER The mechanical indicator used at the CB to indicate the status of the
breaker is called the ___________.
Disconnects - ANSWER __________ must never be used to interrupt current flow in circuit.
Disconnects - ANSWER __________ are usually operated manually by the use of levers,
cranks, and "hook-sticks poles."
current - ANSWER The size of an electric arc and destruction it can cause are directly
proportional to the amount of ___________ being interrupted.
Arc - ANSWER The current that continues to flow across the opening contacts of a switch
(or across any opening in a circuit) is known as an __________.
2025/2026 | 100% Verified Study Guide with Correct
Questions & Answers
Dielectric - ANSWER The ability of a substance to prevent the flow of electrical current is
described as its __________ strength.
Conductors - ANSWER __________ of electricity have no dielectric strength, as they allow
current to flow in a circuit.
Air - ANSWER __________, which has a relatively high dielectric strength, is used as the
dielectric medium in many low voltage applications where current values are also low. A
common example is the light switch found in homes, etc.
Circuit Breakers - ANSWER Some of the materials used in __________that have sufficient
dielectric strength of for interrupting power system current values are: Insulating oils,
pressurized inert gasses, Sulfur Hexafluoride gas, and Vacuum chambers.
,Dirt - ANSWER ___________ and moisture in particular are two elements that can destroy
the interrupting capabilities of a chosen dielectric medium.
explode - ANSWER 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.
Bushings - ANSWER __________ are usually made of insulating porcelain.
Nonconductive - ANSWER Portions of the mechanical linkages connected to movable
contacts must be constructed of __________ materials to prevent the electrical components of
the contacts and conductors from energizing the components of the CB such as the tank, controls,
etc.
0.2 - ANSWER The operating time, from fully open to fully closed, in many large CBs, is
often less than __________ seconds.
linkage - ANSWER Failure of the mechanical __________ (sometimes referred to as the
actuating arm or lever) can cause serious damage to the circuit breaker or may cause normally
non-energized portions of the CB to become energized.
, Control - ANSWER __________ circuits use auxiliary devices that direct the operation of
the CB.
Semaphore - ANSWER The mechanical indicator used at the CB to indicate the status of the
breaker is called the ___________.
Disconnects - ANSWER __________ must never be used to interrupt current flow in circuit.
Disconnects - ANSWER __________ are usually operated manually by the use of levers,
cranks, and "hook-sticks poles."
current - ANSWER The size of an electric arc and destruction it can cause are directly
proportional to the amount of ___________ being interrupted.
Arc - ANSWER The current that continues to flow across the opening contacts of a switch
(or across any opening in a circuit) is known as an __________.
