Epri Study Guide 2026 Questions And Answers Graded

EPRI STUDY GUIDE 2026 QUESTIONS AND ANSWERS
GRADED A+
✔✔An isochronous governor has a droop setting of:
A. 5%
B. 0%
C. 10%
D. 8% - ✔✔B. 0%

✔✔What element of the power system is typically most susceptible to damage
from prolonged operation at frequencies above or below 60 HZ?
A. Transformers greater than 300 MVA
B. Low pressure turbine stage blades
C. Synchronous motors
D. Induction motors - ✔✔B. Low pressure turbine stage blades

✔✔11. Hydro-electric generators typically exhibit better governor response than
thermal generators because:
A. Hydro-electric generators typically have more stored energy
B. Thermal generators typically do not carry spinning reserve
C. Water is a better conductor than steam
D. Hydro-electric generators utilize microprocessor based governors while
thermal units utilize mechanical governors - ✔✔A. Hydro-electric generators typically
have more stored energy

✔✔A generator with a 6% droop governor is connected to a 60 HZ power
system. Initially the generator is at 100% load. Frequency then falls 0.9 HZ.
What is the generator's new % output?
A. 75%
B. 100%
C. 0%
D. 25% - ✔✔B. 100%

✔✔What magnitude of frequency change would cause a 10% droop governor
to move its generator from zero to full output in a 60 HZ system?
A. 6 HZ
B. 10 HZ
C. 3 HZ
D. 5 HZ - ✔✔D. 5 HZ

✔✔Which component of the CPS is intended to limit the magnitude of
unscheduled power flows?
A. DCS 1
B. DCS 2
C. CPS1

,D. CPS2 - ✔✔D. CPS2

✔✔What is the upper limit to the CPS1 magnitude?
A. 50%
B. 100%
C. 200%
D. No limit - ✔✔D. No limit

✔✔What is the Mvar production of a 50 Mvar shunt capacitor that is
energized at 90% of its nominal voltage?
A. 40.5
B. 45
C. 55.6
D. 61.7 - ✔✔A. 40.5

✔✔A 5% change in voltage will typically lead to what change in the total load
magnitude?
A. 2%
B. 3%
C. 5%
D. 10% - ✔✔B. 3%

✔✔A transformer can be overexcited if exposed to:
A. High voltage
B. Low frequency
C. High voltage and low frequency
D. All of the above - ✔✔D. All of the above

✔✔What is the approximate Mvar/Mile production for a 345 kV overhead
line?
A. 1/3
B. 3/4
C. 2.0
D. 5.0 - ✔✔B. 3/4

✔✔A 345 kV transmission line operates at various voltage levels throughout
the day. At which voltage level does the transmission line produce more
Mvar?
A. 345 kV
B. 340 kV
C. 350 kV
D. 360 kV - ✔✔D. 360 kV

✔✔A transmission line has 50 ohms of inductive reactance. 25 ohms of series

, capacitors are inserted in the line. What is the line's % series
compensation?
A. 25%
B. 40%
C. 50%
D. 80% - ✔✔C. 50%

✔✔A transmission line's __________ is the MW loading at which the Mvar
from the line's natural capacitance is equal to the Mvar the line needs to
support its voltage.
A. surge impedance loading
B. angle stability limit
C. voltage stability limit
D. thermal limit - ✔✔A. surge impedance loading

✔✔What is the approximate Mvar/Mile production for a 500 kV overhead
line?
A. 1/3
B. 3/4
C. 2.0
D. 5.0 - ✔✔C. 2.0

✔✔Given a purely inductive load, what can be said about the MVA this load
draws from the power system?
A. The load draws only MW
B. The load draws only Mvar
C. The load magnitude cannot exceed 100 MVA
D. The load magnitude cannot exceed 1000 MVA - ✔✔B. The load draws only Mvar

✔✔A generator with spare Mvar is always a source of dynamic reactive
reserve.
A. True
B. False - ✔✔B. False

✔✔The nominal load is:
A. Equal to the rated load
B. Dependent on the actual voltage and frequency
C. Dependent on the scheduled voltage and frequency
D. Equal to the actual load - ✔✔A. Equal to the rated load

✔✔A period of voltage instability always results in a voltage collapse.
A. True
B. False - ✔✔B. False