NERC Test Questions with complete
solution.verified answers.
A transmission line is operating with a voltage phase angle different of 30
degrees between the sending Vs and the receiving bus Vr. If the receiving end
load is suddenly increased, the voltage phase angle difference will be?
~CORRECT ANSWER~The phase angle will increase. When load is
increased phase angle will increase.
A load has a power factor of 0.9 lagging. If the load draws 100 MVA, what is
the MW draw? ~CORRECT ANSWER~90 pf= mw/mva
The high side of a delta-wye connection transformer is connected to a power
system with 199 kV L-G high side voltage. What is the voltage across the
delta winding of the transformer? ~CORRECT ANSWER~Vl-l= square root
of 3 times Vl-g 1.73x191= 345kV
If a transmission line is carrying 400 MW and 300 MVAR what is the MVA?
~CORRECT ANSWER~3-4-5 triangle 500 MVA
The prime mover is the component of the generator that creates the
rotational force. In a typical coal fired steam generator what component spins
the rotor? ~CORRECT ANSWER~Turbine
Reactive reserve response during a disturbance is best obtained from which
devise? ~CORRECT ANSWER~Synchronous condensers
,For two identically constructed transmission lines where Line A is 150 miles
long and line B is 15 miles long, if both lines are lightly loaded? ~CORRECT
ANSWER~A produces more reactive power than B.
Lightly loaded transmission lines essentially behave like? ~CORRECT
ANSWER~Shunt Capacitors
You receive an alarm that indicates low oil pressure on an underground
transmission cable. SCADA shows the pressure is continuing to drop. What is
the first step you take to protect the line? ~CORRECT ANSWER~Isolate the
line
Computer simulations show that for a 100 MW schedule from Bus A to Bus
B, 63% of the schedule will flow on the scheduled path and the remainder will
flow on other parallel paths. What is the distribution factor for the scheduled
path? ~CORRECT ANSWER~63%
Which statement best describes how reactive power MVAR power normally
flows? ~CORRECT ANSWER~High Voltage to Low Voltage
Which of the following types of data are BA and RC not required to share
with one another? ~CORRECT ANSWER~Generator start up cost
TOP must develop, maintain, and implement formal policies and procedures
to provide for transmission reliability. Which of the following DOES NOT
need to be addressed in these policies and procedures? ~CORRECT
ANSWER~Planned outages of generation units
,A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best
described as? ~CORRECT ANSWER~Operating in a lagging mode.
Inductive system
Which of the following types of MW load is the most impacted by an
intentional frequency reduction? ~CORRECT ANSWER~Motor
Assume there are two 250 mile long transmission lines exporting an
excessive amount of MW from a generation area to a load area. One of the
lines suddenly trips and the area power system collapses within a few
seconds. The most likely cause of the collapse? ~CORRECT
ANSWER~Angle Instability
The phase voltage in a wye-connected load is 277 V. What is the line to line
voltage? ~CORRECT ANSWER~480 V
A simple power system is composed of three lines connecting generation to
load. Each lines the same impedance, is initially loaded at 200 MW, and has
a thermal limit of 400 MW. If one line trips, what the loading on the shortest
remaining line be and will the thermal limit either remaining line be
violated? ~CORRECT ANSWER~300 MW and No
The best prediction of system load is the load forecast tool that uses?
~CORRECT ANSWER~Forecasted Weather
If the phase angel at an open breaker is equal to 1/10 of a cycle, this is the the
same angle as? ~CORRECT ANSWER~1/10 of 360 so 36
, A ___________ tool is used to ensure the power system can respond within
acceptable limits of N-1 ~CORRECT ANSWER~Contingency Analysis
Which of the following activities would not be included in the procedures for
transmission reliability? ~CORRECT ANSWER~Ancillary service pricing
The transmission Operator and BA shall provide documentation that
operating personnel have ______ to implement real time actions to ensure the
stable and reliable operation of the BES. ~CORRECT ANSWER~Proper
NERC Certification Credential
A utility distribution bus has the following customer loads attached. What is
the total customer MW load and is the total customer load capacitive or
inductive? 5 MW 1 MVAR & 3 MW 1 MVAR & 2 MW -2 MVAR & 10 MW 3
MVAR ~CORRECT ANSWER~20 mw and Inductive
How many MVARs does a 230 kV, 50 MVAR capacitor bank provide when the
voltage id 207 kV ~CORRECT ANSWER~Actual MW/ Rated MW ^2 x
Capacitor Rating
40
You are a system operator and the load forecast is for an all time summer
peak load day, generations and reactive resources will be tight. Which
scheduled job would you allow to proceed? ~CORRECT ANSWER~735 kV
shunt reactor maintenance.
solution.verified answers.
A transmission line is operating with a voltage phase angle different of 30
degrees between the sending Vs and the receiving bus Vr. If the receiving end
load is suddenly increased, the voltage phase angle difference will be?
~CORRECT ANSWER~The phase angle will increase. When load is
increased phase angle will increase.
A load has a power factor of 0.9 lagging. If the load draws 100 MVA, what is
the MW draw? ~CORRECT ANSWER~90 pf= mw/mva
The high side of a delta-wye connection transformer is connected to a power
system with 199 kV L-G high side voltage. What is the voltage across the
delta winding of the transformer? ~CORRECT ANSWER~Vl-l= square root
of 3 times Vl-g 1.73x191= 345kV
If a transmission line is carrying 400 MW and 300 MVAR what is the MVA?
~CORRECT ANSWER~3-4-5 triangle 500 MVA
The prime mover is the component of the generator that creates the
rotational force. In a typical coal fired steam generator what component spins
the rotor? ~CORRECT ANSWER~Turbine
Reactive reserve response during a disturbance is best obtained from which
devise? ~CORRECT ANSWER~Synchronous condensers
,For two identically constructed transmission lines where Line A is 150 miles
long and line B is 15 miles long, if both lines are lightly loaded? ~CORRECT
ANSWER~A produces more reactive power than B.
Lightly loaded transmission lines essentially behave like? ~CORRECT
ANSWER~Shunt Capacitors
You receive an alarm that indicates low oil pressure on an underground
transmission cable. SCADA shows the pressure is continuing to drop. What is
the first step you take to protect the line? ~CORRECT ANSWER~Isolate the
line
Computer simulations show that for a 100 MW schedule from Bus A to Bus
B, 63% of the schedule will flow on the scheduled path and the remainder will
flow on other parallel paths. What is the distribution factor for the scheduled
path? ~CORRECT ANSWER~63%
Which statement best describes how reactive power MVAR power normally
flows? ~CORRECT ANSWER~High Voltage to Low Voltage
Which of the following types of data are BA and RC not required to share
with one another? ~CORRECT ANSWER~Generator start up cost
TOP must develop, maintain, and implement formal policies and procedures
to provide for transmission reliability. Which of the following DOES NOT
need to be addressed in these policies and procedures? ~CORRECT
ANSWER~Planned outages of generation units
,A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best
described as? ~CORRECT ANSWER~Operating in a lagging mode.
Inductive system
Which of the following types of MW load is the most impacted by an
intentional frequency reduction? ~CORRECT ANSWER~Motor
Assume there are two 250 mile long transmission lines exporting an
excessive amount of MW from a generation area to a load area. One of the
lines suddenly trips and the area power system collapses within a few
seconds. The most likely cause of the collapse? ~CORRECT
ANSWER~Angle Instability
The phase voltage in a wye-connected load is 277 V. What is the line to line
voltage? ~CORRECT ANSWER~480 V
A simple power system is composed of three lines connecting generation to
load. Each lines the same impedance, is initially loaded at 200 MW, and has
a thermal limit of 400 MW. If one line trips, what the loading on the shortest
remaining line be and will the thermal limit either remaining line be
violated? ~CORRECT ANSWER~300 MW and No
The best prediction of system load is the load forecast tool that uses?
~CORRECT ANSWER~Forecasted Weather
If the phase angel at an open breaker is equal to 1/10 of a cycle, this is the the
same angle as? ~CORRECT ANSWER~1/10 of 360 so 36
, A ___________ tool is used to ensure the power system can respond within
acceptable limits of N-1 ~CORRECT ANSWER~Contingency Analysis
Which of the following activities would not be included in the procedures for
transmission reliability? ~CORRECT ANSWER~Ancillary service pricing
The transmission Operator and BA shall provide documentation that
operating personnel have ______ to implement real time actions to ensure the
stable and reliable operation of the BES. ~CORRECT ANSWER~Proper
NERC Certification Credential
A utility distribution bus has the following customer loads attached. What is
the total customer MW load and is the total customer load capacitive or
inductive? 5 MW 1 MVAR & 3 MW 1 MVAR & 2 MW -2 MVAR & 10 MW 3
MVAR ~CORRECT ANSWER~20 mw and Inductive
How many MVARs does a 230 kV, 50 MVAR capacitor bank provide when the
voltage id 207 kV ~CORRECT ANSWER~Actual MW/ Rated MW ^2 x
Capacitor Rating
40
You are a system operator and the load forecast is for an all time summer
peak load day, generations and reactive resources will be tight. Which
scheduled job would you allow to proceed? ~CORRECT ANSWER~735 kV
shunt reactor maintenance.
