Practice Test NERC Questions With
Correct Answers
Which of the following is a disadvantage of microwave systems? - CORRECT
ANSWER- Radiated beam can be scattered by fog
Microwave telecommunications is often employed for data, voice & control capabilities.
The transmission media in microwave telecommunications systems are: - CORRECT
ANSWER- Air
Assume a system operator issues an operating instruction to a substation operator. The
substation operator repeats back the operating instruction with an error. The operator
shall? - CORRECT ANSWER- Repeat the original statement to resolve the
misunderstanding
Transmission lines are protected by the transfer trip, carrier, and other types of pilot
relay schemes. Pilot relay schemes are necessary for what reason? - CORRECT
ANSWER- Pilot relays allow instantaneous tripping for faults within 10%-20% of the
line distance from the remote terminal with primary protection
While adjusting the tap changer on a large power transformer's protective relay's
operate. The most likely relay to operate would be? - CORRECT ANSWER-
Differential
Load rejection schemes are a form of Remedial Action Schemes RAS. In a load
rejection scheme, the term load refers to the: - CORRECT ANSWER- Generator MW
output
The purpose of the CT and PT is to ________________ the high voltage power source
to the low voltage relays. - CORRECT ANSWER- Step down
High speed transmission protection is a benefit to angle stability because: -
CORRECT ANSWER- Fault duration is reduced, accelerating time is reduced, angle
spread is reduced
What type of relay uses a combination of CT measurements and PT measurements and
operates when the ration of the PT measurements to CT measurements is below a
certain limit for a given period of time? - CORRECT ANSWER- Distance Relay
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 startup 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
Correct Answers
Which of the following is a disadvantage of microwave systems? - CORRECT
ANSWER- Radiated beam can be scattered by fog
Microwave telecommunications is often employed for data, voice & control capabilities.
The transmission media in microwave telecommunications systems are: - CORRECT
ANSWER- Air
Assume a system operator issues an operating instruction to a substation operator. The
substation operator repeats back the operating instruction with an error. The operator
shall? - CORRECT ANSWER- Repeat the original statement to resolve the
misunderstanding
Transmission lines are protected by the transfer trip, carrier, and other types of pilot
relay schemes. Pilot relay schemes are necessary for what reason? - CORRECT
ANSWER- Pilot relays allow instantaneous tripping for faults within 10%-20% of the
line distance from the remote terminal with primary protection
While adjusting the tap changer on a large power transformer's protective relay's
operate. The most likely relay to operate would be? - CORRECT ANSWER-
Differential
Load rejection schemes are a form of Remedial Action Schemes RAS. In a load
rejection scheme, the term load refers to the: - CORRECT ANSWER- Generator MW
output
The purpose of the CT and PT is to ________________ the high voltage power source
to the low voltage relays. - CORRECT ANSWER- Step down
High speed transmission protection is a benefit to angle stability because: -
CORRECT ANSWER- Fault duration is reduced, accelerating time is reduced, angle
spread is reduced
What type of relay uses a combination of CT measurements and PT measurements and
operates when the ration of the PT measurements to CT measurements is below a
certain limit for a given period of time? - CORRECT ANSWER- Distance Relay
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 startup 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
