LADWP Electric Station Operator (Circuit
Breakers, Disconnects, Transformers)
Complete Exam Study Questions with
Accurate Answers
1. One of the primary tasks of the Electric Station Operator is the __________
of high voltage circuits. - ANSWER switching
2. Electrical current may flow across the contacts of ____ to ____ electrical
switches before it reaches the consumer. - ANSWER 50 100
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. - ANSWER improper
4. This is the insulating mechanism that occupies the space between the open
contacts of a CB and prevents the flow of current through the device while
the contacts are in the open position. - ANSWER Dielectric medium
5. The ability of a substance to prevent the flow of electrical current is
described as its __________ strength. - ANSWER Dielectric
6. __________ of electricity have no dielectric strength, as they allow current
to flow in a circuit. - ANSWER Conductors
,7. __________, 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. -
ANSWER Air
8. 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. -
ANSWER Circuit Breakers
9. ___________ and moisture in particular are two elements that can destroy
the interrupting capabilities of a chosen dielectric medium. - ANSWER Dirt
10.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. - ANSWER explode
11.__________ are usually made of insulating porcelain. - ANSWER Bushings
12.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. - ANSWER Nonconductive
13.The operating time, from fully open to fully closed, in many large CBs, is
often less than __________ seconds. - ANSWER 0.2
14.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.
- ANSWER linkage
15.__________ circuits use auxiliary devices that direct the operation of the
CB. - ANSWER Control
16.The mechanical indicator used at the CB to indicate the status of the breaker
is called the ___________. - ANSWER Semaphore
17.__________ must never be used to interrupt current flow in circuit. -
ANSWER Disconnects
18.__________ are usually operated manually by the use of levers, cranks, and
"hook-sticks poles." - ANSWER Disconnects
19.The size of an electric arc and destruction it can cause are directly
proportional to the amount of ___________ being interrupted. - ANSWER
current
20.The current that continues to flow across the opening contacts of a switch (or
across any opening in a circuit) is known as an __________. - ANSWER
Arc
21.Electrical __________ are installed in the path from the generator to the
consumer to provide reliability, flexibility, and safeguards for the electrical
power system. - ANSWER switches
22.Operators use electrical switches to perform routine, automatic, and
____________ switching operations on the electrical system. - ANSWER
emergency
Breakers, Disconnects, Transformers)
Complete Exam Study Questions with
Accurate Answers
1. One of the primary tasks of the Electric Station Operator is the __________
of high voltage circuits. - ANSWER switching
2. Electrical current may flow across the contacts of ____ to ____ electrical
switches before it reaches the consumer. - ANSWER 50 100
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. - ANSWER improper
4. This is the insulating mechanism that occupies the space between the open
contacts of a CB and prevents the flow of current through the device while
the contacts are in the open position. - ANSWER Dielectric medium
5. The ability of a substance to prevent the flow of electrical current is
described as its __________ strength. - ANSWER Dielectric
6. __________ of electricity have no dielectric strength, as they allow current
to flow in a circuit. - ANSWER Conductors
,7. __________, 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. -
ANSWER Air
8. 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. -
ANSWER Circuit Breakers
9. ___________ and moisture in particular are two elements that can destroy
the interrupting capabilities of a chosen dielectric medium. - ANSWER Dirt
10.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. - ANSWER explode
11.__________ are usually made of insulating porcelain. - ANSWER Bushings
12.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. - ANSWER Nonconductive
13.The operating time, from fully open to fully closed, in many large CBs, is
often less than __________ seconds. - ANSWER 0.2
14.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.
- ANSWER linkage
15.__________ circuits use auxiliary devices that direct the operation of the
CB. - ANSWER Control
16.The mechanical indicator used at the CB to indicate the status of the breaker
is called the ___________. - ANSWER Semaphore
17.__________ must never be used to interrupt current flow in circuit. -
ANSWER Disconnects
18.__________ are usually operated manually by the use of levers, cranks, and
"hook-sticks poles." - ANSWER Disconnects
19.The size of an electric arc and destruction it can cause are directly
proportional to the amount of ___________ being interrupted. - ANSWER
current
20.The current that continues to flow across the opening contacts of a switch (or
across any opening in a circuit) is known as an __________. - ANSWER
Arc
21.Electrical __________ are installed in the path from the generator to the
consumer to provide reliability, flexibility, and safeguards for the electrical
power system. - ANSWER switches
22.Operators use electrical switches to perform routine, automatic, and
____________ switching operations on the electrical system. - ANSWER
emergency
