NERC EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES |ALREADY GRADED
A+ | LATEST UPDATE
A 50 MVA rated transformer has 30 MW of load. How many MVARs can flow through the transformer
without exceeding the rating?
A. 50 MVAR
B. 40 MVAR
C. 30 MVAR
D. 80 MVAR - ANSWER-B. 40 MVAR
A balancing authority is responsible for load - interchange - generation balance, which calculated value
reflects that balance?
A. Frequency
B. System Lambda
C. Operating reserves
D. ACE - ANSWER-D. ACE
A transmission line has a net VAR load of 25 MVAR into the line resembles which of these statements?
A. The line is equivalent to an inductor
B. The line is transferring the optimum load
C. The line is nearing voltage collapse
D. The line is equivalent to a capacitor - ANSWER-A. The line is equivalent to an inductor
Frequency of the power system is mainly determined by which factor?
A. Load and generation balance in your balancing authority area
B. Load and generation balance in the interconnection
C. Generation power flowing on the transmission lines
D. Load requirement of each power system - ANSWER-B. Load and generation balance in the
interconnection
,Generator reactive power output increases dynamically under which condition?
A. Low voltage
B. High voltage
C. Transmission line trip
D. Energy and capacity deficiency - ANSWER-A. Low voltage
If interconnection frequency is 59.95 Hz, how do balancing authorities support interconnection
frequency?
A. Remain at current MW output level
B. Increasing MW output
C. Decreasing MW output
D. Increasing excitation on the field windings - ANSWER-B. Increasing MW output
In a power system which type of power is especially critical to support heavily loaded transmission lines
and to have dynamic reserves in preparation for contingency?
A. Reactive power
B. Real power
C. Power flow
D. Apparent power - ANSWER-A. Reactive power
Reactive power is needed to support which type of load?
A. Capacitive
B. Resistive
C. Impedance
D. Inductive - ANSWER-D. Inductive
System inertia is the ability of a power system to:
A. Increase the speed of the rotation of the units resulting in an increase in system frequency
, B. Decrease the speed of the rotation of the units resulting in a decrease in system frequency
C. Oppose changes in frequency due to resistance provided by kinetic energy of the rotating masses
D. All of the above - ANSWER-D. All of the above
The ACE equation must include which metered data in addition to the dynamic schedules, pseudo ties,
actual frequency?
A. Generation
B. Transformers
C. Tie Lines
D. Communications - ANSWER-C. Tie Lines
The load on a power transformer is 40 MW and 30 MVAR. What is the transformer's power factor?
A. 0.80
B. 0.70
C. 0.60
D. 0.50 - ANSWER-A. 0.80
The primary cause of low voltage is:
A. VAR losses associated with heavy power transfers
B. Insufficient generation
C. Insufficient transmission capacity
D. Insufficient shunt reactors in service - ANSWER-A. VAR losses associated with heavy power transfers
What causes real power losses on the bulk power system?
A. Current flow causing heating
B. Load that is not online
C. High cost generation
D. Inefficient heat rates - ANSWER-A. Current flow causing heating
ANSWERS WITH RATIONALES |ALREADY GRADED
A+ | LATEST UPDATE
A 50 MVA rated transformer has 30 MW of load. How many MVARs can flow through the transformer
without exceeding the rating?
A. 50 MVAR
B. 40 MVAR
C. 30 MVAR
D. 80 MVAR - ANSWER-B. 40 MVAR
A balancing authority is responsible for load - interchange - generation balance, which calculated value
reflects that balance?
A. Frequency
B. System Lambda
C. Operating reserves
D. ACE - ANSWER-D. ACE
A transmission line has a net VAR load of 25 MVAR into the line resembles which of these statements?
A. The line is equivalent to an inductor
B. The line is transferring the optimum load
C. The line is nearing voltage collapse
D. The line is equivalent to a capacitor - ANSWER-A. The line is equivalent to an inductor
Frequency of the power system is mainly determined by which factor?
A. Load and generation balance in your balancing authority area
B. Load and generation balance in the interconnection
C. Generation power flowing on the transmission lines
D. Load requirement of each power system - ANSWER-B. Load and generation balance in the
interconnection
,Generator reactive power output increases dynamically under which condition?
A. Low voltage
B. High voltage
C. Transmission line trip
D. Energy and capacity deficiency - ANSWER-A. Low voltage
If interconnection frequency is 59.95 Hz, how do balancing authorities support interconnection
frequency?
A. Remain at current MW output level
B. Increasing MW output
C. Decreasing MW output
D. Increasing excitation on the field windings - ANSWER-B. Increasing MW output
In a power system which type of power is especially critical to support heavily loaded transmission lines
and to have dynamic reserves in preparation for contingency?
A. Reactive power
B. Real power
C. Power flow
D. Apparent power - ANSWER-A. Reactive power
Reactive power is needed to support which type of load?
A. Capacitive
B. Resistive
C. Impedance
D. Inductive - ANSWER-D. Inductive
System inertia is the ability of a power system to:
A. Increase the speed of the rotation of the units resulting in an increase in system frequency
, B. Decrease the speed of the rotation of the units resulting in a decrease in system frequency
C. Oppose changes in frequency due to resistance provided by kinetic energy of the rotating masses
D. All of the above - ANSWER-D. All of the above
The ACE equation must include which metered data in addition to the dynamic schedules, pseudo ties,
actual frequency?
A. Generation
B. Transformers
C. Tie Lines
D. Communications - ANSWER-C. Tie Lines
The load on a power transformer is 40 MW and 30 MVAR. What is the transformer's power factor?
A. 0.80
B. 0.70
C. 0.60
D. 0.50 - ANSWER-A. 0.80
The primary cause of low voltage is:
A. VAR losses associated with heavy power transfers
B. Insufficient generation
C. Insufficient transmission capacity
D. Insufficient shunt reactors in service - ANSWER-A. VAR losses associated with heavy power transfers
What causes real power losses on the bulk power system?
A. Current flow causing heating
B. Load that is not online
C. High cost generation
D. Inefficient heat rates - ANSWER-A. Current flow causing heating
