Certified Power Systems Operator
Practice Examination Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. What is the primary purpose of Automatic Generation Control (AGC)?
A. To reduce transmission line impedance
B. To maintain system frequency and interchange schedules
C. To increase generator inertia
D. To improve substation grounding
Rationale: AGC adjusts real power output to maintain frequency and
scheduled power interchange.
2. What happens to system frequency if generation is greater than load?
A. Frequency decreases
B. Frequency increases
, C. Voltage collapses
D. Transmission lines overload
Rationale: Excess generation causes frequency to rise above
nominal.
3. Which relay is used primarily for detecting short-circuits by current
magnitude?
A. Distance relay
B. Overvoltage relay
C. Overcurrent relay
D. Differential relay
Rationale: Overcurrent relays operate when current exceeds a preset
threshold indicating faults.
4. What device automatically disconnects equipment during unsafe
system conditions?
A. Recloser
B. Capacitor bank
C. Protective relay
D. Load tap changer
Rationale: Protective relays sense abnormal conditions and trip
breakers.
5. A decrease in system voltage typically indicates:
A. Surplus reactive power
B. Reactive power deficiency
, C. Excess real power
D. Load shedding
Rationale: Low voltage often results from insufficient VAR support.
6. A generator's governor primarily controls:
A. Voltage
B. Real power output
C. VAR compensation
D. Breaker timing
Rationale: Governor adjusts turbine input to regulate real power and
frequency.
7. A transformer tap changer is used to regulate:
A. Frequency
B. Voltage
C. Rotor angle stability
D. Power factor
Rationale: Tap adjustments maintain customer voltage within limits.
8. Which of the following carries both real and reactive power?
A. Ground wire
B. Transmission line
C. Lightning arrester
D. Surge capacitor
Rationale: Transmission lines carry complex power to loads.
Practice Examination Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of Automatic Generation Control (AGC)?
A. To reduce transmission line impedance
B. To maintain system frequency and interchange schedules
C. To increase generator inertia
D. To improve substation grounding
Rationale: AGC adjusts real power output to maintain frequency and
scheduled power interchange.
2. What happens to system frequency if generation is greater than load?
A. Frequency decreases
B. Frequency increases
, C. Voltage collapses
D. Transmission lines overload
Rationale: Excess generation causes frequency to rise above
nominal.
3. Which relay is used primarily for detecting short-circuits by current
magnitude?
A. Distance relay
B. Overvoltage relay
C. Overcurrent relay
D. Differential relay
Rationale: Overcurrent relays operate when current exceeds a preset
threshold indicating faults.
4. What device automatically disconnects equipment during unsafe
system conditions?
A. Recloser
B. Capacitor bank
C. Protective relay
D. Load tap changer
Rationale: Protective relays sense abnormal conditions and trip
breakers.
5. A decrease in system voltage typically indicates:
A. Surplus reactive power
B. Reactive power deficiency
, C. Excess real power
D. Load shedding
Rationale: Low voltage often results from insufficient VAR support.
6. A generator's governor primarily controls:
A. Voltage
B. Real power output
C. VAR compensation
D. Breaker timing
Rationale: Governor adjusts turbine input to regulate real power and
frequency.
7. A transformer tap changer is used to regulate:
A. Frequency
B. Voltage
C. Rotor angle stability
D. Power factor
Rationale: Tap adjustments maintain customer voltage within limits.
8. Which of the following carries both real and reactive power?
A. Ground wire
B. Transmission line
C. Lightning arrester
D. Surge capacitor
Rationale: Transmission lines carry complex power to loads.
