EPRI Practice Test -Questions And Verified Answers
If a generator is producing 500 MW and 200 Mvar, is the generator?
A. Leading
B. Lagging
C. Underexcited
D. Dropping ✔️Ans -B. Lagging
What is the IEEE device number for a differential relay?
A. 87
B. 86
C. 67
D. 50 ✔️Ans -A. 87
Can a synchronous machine have a negative torque angle? What does
this mean?
A. Yes / the machine is absorbing reactive power
B. No / the machine is absorbing active power
C. No / the machine is absorbing reactive power
D. Yes / the machine is absorbing active power ✔️Ans -D. Yes / the
machine is absorbing active power
A customer load is fed at 120 volts. The customer voltage is doubled
while the load magnitude stays the same. What effect does this have on
the power losses?
A. Doubles the losses
B. Halves the losses
C. Increases the losses by a factor of four
D. Decreases the losses by a factor of four ✔️Ans -D. Decreases the
losses by a factor of four
In a DC circuit, a 100 volt battery is connected to both sides of a 2 ohm
resistor. What is the current through the resistor and the power usage of
the resistor?
A. 50 amps / 5000 watts
B. 40 amps / 80 watts
C. 50 amps / 100 watts
D. 40 amps / 3200 watts ✔️Ans -A. 50 amps / 5000 watts
,The actual voltage is 362 kV on a 345 kV bus. What is the p.u. voltage?
A. 1.0
B. 1.05
C. 1.5
D. .95 ✔️Ans -B. 1.05
A load has a power factor of 0.9 lagging. If the load draws 100 MVA,
what is the MW draw?
A. 100
B. 90
C. 111
D. 44 ✔️Ans -B. 90
Which of the following is NOT a synchronizing variable?
A. Phase angle
B. Frequency difference
C. Voltage magnitude difference
D. MW flow differential ✔️Ans -D. MW flow differential
In a typical multi-stage steam turbine, the governor control valves control
the steam entry to the:
A. high pressure turbine
B. intermediate pressure turbine
C. low pressure turbine
D. crossover ✔️Ans -A. high pressure turbine
The high side of a delta-wye connected transformer is connected to a
power system with 199 kV L-G high side voltage. What is the voltage
across the winding of the delta transformer?
A. 199 kV
B. 230 kV
C. 345 kV
D. 500 kV ✔️Ans -C. 345 kV
Thermal limits are the direct result of?
A. High torque and power angles
B. The thermal capability of system equipment
C. A reactive power deficiency
, D. All of the above ✔️Ans -B. The thermal capability of system
equipment
Reactive power flow is influenced more by system power and torque
angles than reactive power.
A. True
B. False ✔️Ans -B. False
At what line power angle does the MW transfer across a transmission path
equal ½ of the path's PMAX?
A. 15 degrees
B. 20 degrees
C. 30 degrees
D. 45 degrees ✔️Ans -C. 30 degrees
A transmission line is rated at 1000 MVA. The power flow is currently 0
MW and 1001 Mvar. Is the transmission line overloaded?
A. Yes
B. No
C. Impossible to determine
D. The line has no load ✔️Ans -A. Yes
The TTC limit has been determine to be 1000 MW from east to west for a
particular transmission path. The transmission path operator sells 500
MW of this TTC. What is the path's ATC?
A. 1000 MW
B. 1500 MW
C. 0 MW
D. 500 MW ✔️Ans -D. 500 MW
A distribution line is rated at 50 MVA. The line's power flow is currently
50 MW and -50 Mvar. This distribution line is overloaded.
A. True
B. False ✔️Ans -A. True
Angle stability limits are the result of?
A. High torque and power angles
B. The thermal capability of system equipment
C. A reactive power deficiency
If a generator is producing 500 MW and 200 Mvar, is the generator?
A. Leading
B. Lagging
C. Underexcited
D. Dropping ✔️Ans -B. Lagging
What is the IEEE device number for a differential relay?
A. 87
B. 86
C. 67
D. 50 ✔️Ans -A. 87
Can a synchronous machine have a negative torque angle? What does
this mean?
A. Yes / the machine is absorbing reactive power
B. No / the machine is absorbing active power
C. No / the machine is absorbing reactive power
D. Yes / the machine is absorbing active power ✔️Ans -D. Yes / the
machine is absorbing active power
A customer load is fed at 120 volts. The customer voltage is doubled
while the load magnitude stays the same. What effect does this have on
the power losses?
A. Doubles the losses
B. Halves the losses
C. Increases the losses by a factor of four
D. Decreases the losses by a factor of four ✔️Ans -D. Decreases the
losses by a factor of four
In a DC circuit, a 100 volt battery is connected to both sides of a 2 ohm
resistor. What is the current through the resistor and the power usage of
the resistor?
A. 50 amps / 5000 watts
B. 40 amps / 80 watts
C. 50 amps / 100 watts
D. 40 amps / 3200 watts ✔️Ans -A. 50 amps / 5000 watts
,The actual voltage is 362 kV on a 345 kV bus. What is the p.u. voltage?
A. 1.0
B. 1.05
C. 1.5
D. .95 ✔️Ans -B. 1.05
A load has a power factor of 0.9 lagging. If the load draws 100 MVA,
what is the MW draw?
A. 100
B. 90
C. 111
D. 44 ✔️Ans -B. 90
Which of the following is NOT a synchronizing variable?
A. Phase angle
B. Frequency difference
C. Voltage magnitude difference
D. MW flow differential ✔️Ans -D. MW flow differential
In a typical multi-stage steam turbine, the governor control valves control
the steam entry to the:
A. high pressure turbine
B. intermediate pressure turbine
C. low pressure turbine
D. crossover ✔️Ans -A. high pressure turbine
The high side of a delta-wye connected transformer is connected to a
power system with 199 kV L-G high side voltage. What is the voltage
across the winding of the delta transformer?
A. 199 kV
B. 230 kV
C. 345 kV
D. 500 kV ✔️Ans -C. 345 kV
Thermal limits are the direct result of?
A. High torque and power angles
B. The thermal capability of system equipment
C. A reactive power deficiency
, D. All of the above ✔️Ans -B. The thermal capability of system
equipment
Reactive power flow is influenced more by system power and torque
angles than reactive power.
A. True
B. False ✔️Ans -B. False
At what line power angle does the MW transfer across a transmission path
equal ½ of the path's PMAX?
A. 15 degrees
B. 20 degrees
C. 30 degrees
D. 45 degrees ✔️Ans -C. 30 degrees
A transmission line is rated at 1000 MVA. The power flow is currently 0
MW and 1001 Mvar. Is the transmission line overloaded?
A. Yes
B. No
C. Impossible to determine
D. The line has no load ✔️Ans -A. Yes
The TTC limit has been determine to be 1000 MW from east to west for a
particular transmission path. The transmission path operator sells 500
MW of this TTC. What is the path's ATC?
A. 1000 MW
B. 1500 MW
C. 0 MW
D. 500 MW ✔️Ans -D. 500 MW
A distribution line is rated at 50 MVA. The line's power flow is currently
50 MW and -50 Mvar. This distribution line is overloaded.
A. True
B. False ✔️Ans -A. True
Angle stability limits are the result of?
A. High torque and power angles
B. The thermal capability of system equipment
C. A reactive power deficiency
