PRACTICE TEST NERC EXAM
QUESTIONS WITH VERIFIED
ANSWERS. A+ GRADE 2025/2026.
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? - ANS 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? -
ANS 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? -
ANS 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? - ANS 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? - ANS Turbine
Reactive reserve response during a disturbance is best obtained from which devise? -
ANS Synchronous condensers
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,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? - ANS A produces more reactive power than B.
Lightly loaded transmission lines essentially behave like? - ANS 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? - ANS 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? - ANS 63%
Which statement best describes how reactive power MVAR power normally flows? -
ANS High Voltage to Low Voltage
Which of the following types of data are BA and RC not required to share with one another? -
ANS 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? - ANS Planned outages of generation units
A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best described as? -
ANS Operating in a lagging mode. Inductive system
Which of the following types of MW load is the most impacted by an intentional frequency
reduction? - ANS 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? - ANS Angle
Instability
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, The phase voltage in a wye-connected load is 277 V. What is the line to line voltage? -
ANS 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? - ANS 300 MW and No
The best prediction of system load is the load forecast tool that uses? - ANS 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? -
ANS 1/10 of 360 so 36
A ___________ tool is used to ensure the power system can respond within acceptable limits of
N-1 - ANS Contingency Analysis
Which of the following activities would not be included in the procedures for transmission
reliability? - ANS 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. -
ANS 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 - ANS 20 mw and Inductive
How many MVARs does a 230 kV, 50 MVAR capacitor bank provide when the voltage id 207 kV -
ANS Actual MW/ Rated MW ^2 x Capacitor Rating
40
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
QUESTIONS WITH VERIFIED
ANSWERS. A+ GRADE 2025/2026.
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? - ANS 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? -
ANS 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? -
ANS 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? - ANS 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? - ANS Turbine
Reactive reserve response during a disturbance is best obtained from which devise? -
ANS Synchronous condensers
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,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? - ANS A produces more reactive power than B.
Lightly loaded transmission lines essentially behave like? - ANS 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? - ANS 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? - ANS 63%
Which statement best describes how reactive power MVAR power normally flows? -
ANS High Voltage to Low Voltage
Which of the following types of data are BA and RC not required to share with one another? -
ANS 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? - ANS Planned outages of generation units
A 1000 MVA rated generator that produces 800 MW and 100 MVAR is best described as? -
ANS Operating in a lagging mode. Inductive system
Which of the following types of MW load is the most impacted by an intentional frequency
reduction? - ANS 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? - ANS Angle
Instability
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, The phase voltage in a wye-connected load is 277 V. What is the line to line voltage? -
ANS 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? - ANS 300 MW and No
The best prediction of system load is the load forecast tool that uses? - ANS 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? -
ANS 1/10 of 360 so 36
A ___________ tool is used to ensure the power system can respond within acceptable limits of
N-1 - ANS Contingency Analysis
Which of the following activities would not be included in the procedures for transmission
reliability? - ANS 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. -
ANS 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 - ANS 20 mw and Inductive
How many MVARs does a 230 kV, 50 MVAR capacitor bank provide when the voltage id 207 kV -
ANS Actual MW/ Rated MW ^2 x Capacitor Rating
40
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
