SOS NERC PREP-RELIABILITY EXAMS WITH
ACTUAL CORRECT QUESTIONS AND VERIFIED
DETAILED RATIONALES ANSWERS LATEST 2024
ALREADY GRADED A+
A Balancing Authority has a 200 MW/0.1 Hz frequency bias with zero schedules. Frequency is 60.00 Hz
and ACE is 0, what should the sum of all the Balancing Authorities Interconnection ties equal?
A) Small MW amount out of the BA
B) System Load
C) Zero
D) Total Generation
C) Zero
A simple power system is composed of three transmission lines that connect the generation area to the
load area. The three lines are different lengths, but each line has the same impedance. Each line is
initially loaded at 200 MW. The SOL of each line is 400 MW. If one of the three lines trips, what will be
the loading on the shortest remaining line and will the SOL of either remaining line be violated?
A) 400 MW/Yes
B) 400 MW/No
C) 300 MW/Yes
D) 300 MW/No
D) 300 MW/No
During a lightning storm, a fault on a transmission line results in the transmission relay operating and
locking-out. The transmission line cannot be returned to service. After running a contingency analysis,
the Transmission Operator realizes that if another transmission line relays, there could be cascading
outages into a neighboring system. Which of the following actions is appropriate for the Transmission
Operator?
A) Reduce transmission voltages by 5% to reduce customer demand.
B) Notify others in the Interconnection of the situation via an Interconnection-wide telecommunications
system.
C) Continue operations without notifying anyone but try to reduce system loading.
D) Prepare a disturbance report and forward it to the Reliability Coordinator.
B) Notify others in the Interconnection of the situation via an Interconnection-wide telecommunications
system.
,A Generator Operator has some vibration problems with a 500MW coal fired steam generator. As the
result of the vibration problems the Generator Operator has to set the maximum reactive power
production for that unit at 25 Megavar instead of the normal 200 Megavar. Who should the generator
operator notify as the result of this problem?
A) Transmission Operator
B) System Coordinator
C) Department of Energy (DOE)
D) Regional Reliability Organization
A) Transmission Operator
A high voltage transmission line was scheduled out for routine maintenance several weeks in advance.
On the scheduled outage date, field personnel call to inform the system operator that they will be taking
the line out of service. Bad weather the previous day has forced other outages. What should the system
operator do?
A) Wait until peak is over to make a decision
B) Run a power flow study to determine the effects of this line outage
C) Do not allow the outage
D) Allow the outage because it was scheduled in advanced
B) Run a power flow study to determine the effects of this line outage
Interconnection frequency is 60.20 Hz. Your ACE is a large positive value and your AGC is pulsing your
units down. What should you do?
A) Suspend AGC and investigate.
B) Place AGC in flat tie line control.
C) Leave AGC in operation as your units respond.
D) Place AGC in constant frequency control.
C) Leave AGC in operation as your units respond.
Which of the following is the most common effect of a Geomagnetic Disturbance on the power system?
A) Increase static electricity
B) Transformer cores becoming saturated
C) Generator output varies
D) Abnormal VAR direction
B) Transformer cores becoming saturated
In a power system, which type of power provides indication of voltage problems, is critical for support of
heavily loaded transmission lines, and is necessary to have sufficient dynamic reserves in preparation for
,a contingency?
A) Solar Power
B) Real Power
C) Reactive Power
D) Apparent Power
C) Reactive Power
You are a transmission operator and you have several large generators operating at full load on the
western portion of your transmission system with 34 kV and 230 kV transmission lines connecting the
generators to the larger metropolitan and Industrial areas in the eastern portion of your transmission
system. You realize by SCADA indications that there is a large power angle approaching 88 degrees
between some of the sending busses at the generation sites and the receiving buses around the load
areas. You realize that the slightest contingency on the system could elevate the power angle above 90
degrees which could cause the generation and load areas to lose synchronism. What would be some of
your first immediate responses to prevent this from happening?
A) Raise the bus voltage at the receiving buses and at the sending buses, if possible. Then, have the
balancing operator provide additional generation on line on th
A) Raise the bus voltage at the receiving buses and at the sending buses, if possible. Then, have the
balancing operator provide additional generation on line on the eastern portion of the large
metropolitan area
A System Operator must operate the transmission system so that instability, uncontrolled separation, or
cascading outages will not occur as a result of _________.
A) The most severe single contingency
B) Normal operations
C) External disturbances
D) Any unplanned outage
A) The most severe single contingency
Which of the following actions would be required in accordance with COM-002-4 when communicating
an Operating Instruction?
A) A Balancing Authority repeats the operating instruction back to the Reliability Coordinator.
B) A Reliability Coordinator clearly states the Operating Instruction.
C) A Reliability Coordinator confirms the instruction was understood correctly or corrects the response if
it is not repeated back correctly.
D) All the Above
, D) All the Above
The largest single contingency for Balancing Authority A is a unit rated at 900 MW. Which of the
following disturbances would constitute a reportable disturbance for DCS evaluation based on the NERC
DCS criteria?
A) The loss of the 900 MW generating unit at 60% output.
B) The loss of two 400 MW units 30 seconds apart.
C) The loss of 750 MW of firm load.
D) The loss of a 700 MW generating unit at 100% output.
B) The loss of two 400 MW units 30 seconds apart.
On a mild spring day, a transmission line trips. The line then trips again when energized. Which of the
following is least likely to be the problem?
A) Vandalism
B) Overload
C) Equipment failure
D) Sabotage
B) Overload
Which of the following is NOT a requirement of the Reliability Coordinator concerning GMDs?
A) Identify conflicts in their area's Transmission Operator plans
B) Specify actions to be included in the Transmission Operator's GMD Operating Procedures
C) Disseminate information concerning GMDs to entities in the Reliability Coordinator's Operating Plan
D) Coordinate the GMD Operating Procedures of Transmission Operators in their area
B) Specify actions to be included in the Transmission Operator's GMD Operating Procedures
A transformer rated at 50 MVA is currently carrying 30 MW of load. At this load, what is the maximum
allowable MVAR flow through the transformer?
A) 50 MVAR
B) 30 MVAR
C) 40 MVAR
D) 0 MVAR
C) 40 MVAR
ACTUAL CORRECT QUESTIONS AND VERIFIED
DETAILED RATIONALES ANSWERS LATEST 2024
ALREADY GRADED A+
A Balancing Authority has a 200 MW/0.1 Hz frequency bias with zero schedules. Frequency is 60.00 Hz
and ACE is 0, what should the sum of all the Balancing Authorities Interconnection ties equal?
A) Small MW amount out of the BA
B) System Load
C) Zero
D) Total Generation
C) Zero
A simple power system is composed of three transmission lines that connect the generation area to the
load area. The three lines are different lengths, but each line has the same impedance. Each line is
initially loaded at 200 MW. The SOL of each line is 400 MW. If one of the three lines trips, what will be
the loading on the shortest remaining line and will the SOL of either remaining line be violated?
A) 400 MW/Yes
B) 400 MW/No
C) 300 MW/Yes
D) 300 MW/No
D) 300 MW/No
During a lightning storm, a fault on a transmission line results in the transmission relay operating and
locking-out. The transmission line cannot be returned to service. After running a contingency analysis,
the Transmission Operator realizes that if another transmission line relays, there could be cascading
outages into a neighboring system. Which of the following actions is appropriate for the Transmission
Operator?
A) Reduce transmission voltages by 5% to reduce customer demand.
B) Notify others in the Interconnection of the situation via an Interconnection-wide telecommunications
system.
C) Continue operations without notifying anyone but try to reduce system loading.
D) Prepare a disturbance report and forward it to the Reliability Coordinator.
B) Notify others in the Interconnection of the situation via an Interconnection-wide telecommunications
system.
,A Generator Operator has some vibration problems with a 500MW coal fired steam generator. As the
result of the vibration problems the Generator Operator has to set the maximum reactive power
production for that unit at 25 Megavar instead of the normal 200 Megavar. Who should the generator
operator notify as the result of this problem?
A) Transmission Operator
B) System Coordinator
C) Department of Energy (DOE)
D) Regional Reliability Organization
A) Transmission Operator
A high voltage transmission line was scheduled out for routine maintenance several weeks in advance.
On the scheduled outage date, field personnel call to inform the system operator that they will be taking
the line out of service. Bad weather the previous day has forced other outages. What should the system
operator do?
A) Wait until peak is over to make a decision
B) Run a power flow study to determine the effects of this line outage
C) Do not allow the outage
D) Allow the outage because it was scheduled in advanced
B) Run a power flow study to determine the effects of this line outage
Interconnection frequency is 60.20 Hz. Your ACE is a large positive value and your AGC is pulsing your
units down. What should you do?
A) Suspend AGC and investigate.
B) Place AGC in flat tie line control.
C) Leave AGC in operation as your units respond.
D) Place AGC in constant frequency control.
C) Leave AGC in operation as your units respond.
Which of the following is the most common effect of a Geomagnetic Disturbance on the power system?
A) Increase static electricity
B) Transformer cores becoming saturated
C) Generator output varies
D) Abnormal VAR direction
B) Transformer cores becoming saturated
In a power system, which type of power provides indication of voltage problems, is critical for support of
heavily loaded transmission lines, and is necessary to have sufficient dynamic reserves in preparation for
,a contingency?
A) Solar Power
B) Real Power
C) Reactive Power
D) Apparent Power
C) Reactive Power
You are a transmission operator and you have several large generators operating at full load on the
western portion of your transmission system with 34 kV and 230 kV transmission lines connecting the
generators to the larger metropolitan and Industrial areas in the eastern portion of your transmission
system. You realize by SCADA indications that there is a large power angle approaching 88 degrees
between some of the sending busses at the generation sites and the receiving buses around the load
areas. You realize that the slightest contingency on the system could elevate the power angle above 90
degrees which could cause the generation and load areas to lose synchronism. What would be some of
your first immediate responses to prevent this from happening?
A) Raise the bus voltage at the receiving buses and at the sending buses, if possible. Then, have the
balancing operator provide additional generation on line on th
A) Raise the bus voltage at the receiving buses and at the sending buses, if possible. Then, have the
balancing operator provide additional generation on line on the eastern portion of the large
metropolitan area
A System Operator must operate the transmission system so that instability, uncontrolled separation, or
cascading outages will not occur as a result of _________.
A) The most severe single contingency
B) Normal operations
C) External disturbances
D) Any unplanned outage
A) The most severe single contingency
Which of the following actions would be required in accordance with COM-002-4 when communicating
an Operating Instruction?
A) A Balancing Authority repeats the operating instruction back to the Reliability Coordinator.
B) A Reliability Coordinator clearly states the Operating Instruction.
C) A Reliability Coordinator confirms the instruction was understood correctly or corrects the response if
it is not repeated back correctly.
D) All the Above
, D) All the Above
The largest single contingency for Balancing Authority A is a unit rated at 900 MW. Which of the
following disturbances would constitute a reportable disturbance for DCS evaluation based on the NERC
DCS criteria?
A) The loss of the 900 MW generating unit at 60% output.
B) The loss of two 400 MW units 30 seconds apart.
C) The loss of 750 MW of firm load.
D) The loss of a 700 MW generating unit at 100% output.
B) The loss of two 400 MW units 30 seconds apart.
On a mild spring day, a transmission line trips. The line then trips again when energized. Which of the
following is least likely to be the problem?
A) Vandalism
B) Overload
C) Equipment failure
D) Sabotage
B) Overload
Which of the following is NOT a requirement of the Reliability Coordinator concerning GMDs?
A) Identify conflicts in their area's Transmission Operator plans
B) Specify actions to be included in the Transmission Operator's GMD Operating Procedures
C) Disseminate information concerning GMDs to entities in the Reliability Coordinator's Operating Plan
D) Coordinate the GMD Operating Procedures of Transmission Operators in their area
B) Specify actions to be included in the Transmission Operator's GMD Operating Procedures
A transformer rated at 50 MVA is currently carrying 30 MW of load. At this load, what is the maximum
allowable MVAR flow through the transformer?
A) 50 MVAR
B) 30 MVAR
C) 40 MVAR
D) 0 MVAR
C) 40 MVAR
